Valgus Considered: Redefining Total Knee Arthroplasty Alignment for Optimal Patient Outcomes

Valgus Considered: Redefining Total Knee Arthroplasty Alignment for Optimal Patient Outcomes | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Valgus Considered: Redefining Total Knee Arthroplasty Alignment for Optimal Patient Outcomes Runze Zhou, Hanyang Sun, Zhanqi Wei, Yixin Bian, Wei Zhu, Bin Feng, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7329372/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Valgus knees are common deformities induced by osteoarthritis (OA), which is usually characterized by a hip–knee angle (HKA)>3° valgus or a femoral-tibial angle (FTA)<170°. Total knee arthroplasty (TKA) is a pivotal treatment for valgus knee deformity in end-stage knee OA; however, the optimal alignment strategy remains a subject of debate. Traditionally, TKA aims for a neutral mechanical alignment (-3°< HKA 3°) alignment post-TKA has not been extensively studied. Methods: This retrospective study included patients with knee valgus who underwent TKA from September 2011 to September 2021. Patients were divided into two groups on the basis of postoperative HKA: neutral alignment (NA group) (-3°<HKA3°). The clinical outcomes were assessed by the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), KSS, Hospital for Special Surgery (HSS) knee score, range of motion (ROM) and visual analog scale (VAS). Patient satisfaction and radiographic outcomes were also compared between the two groups. Results: A follow-up of 3–10 years was conducted on 99 patients, with an average age of 5.9 years, with no significant demographic differences between the NA and UA groups. Surgical outcomes, including hospital stay, operation duration, and total blood loss, were not obviously different. Pain scores were also measured by the WOMAC and were not significantly different between the two groups, nor were visual analog scale (VAS) scores or pain during movement. The clinical scores (KSS, HSS, and WOMAC function, stiffness, and total scores) and range of motion (ROM) were also comparable, as was patient satisfaction. The radiographic results demonstrated that the preoperative HKA was similar, but the postoperative HKA was significantly greater (p<0.0001, ****) in the UA group due to the study design. Other radiographic results, including the medial and posterior tibial slopes (PTS), mechanical lateral distal femoral angle (mLDFA) and mechanical medial proximal tibial angle (mMPTA), showed no significant differences preoperatively, but the postoperative mLDFA was significantly lower in the UA group (p<0.0001, **** ). The incidence of complications and survival did not markedly differ between the groups. Conclusion: This study revealed no significant differences in postoperative outcomes between TKA patients with neutral alignment and those with slight valgus retention. This suggests that retaining slight valgus of an average of 6.3° may not compromise the success of TKA and could offer an alternative standard for surgical planning. Total Knee Arthroplasty Valgus Deformity Alignment Postoperative Prognosis Patient Satisfaction Figures Figure 1 Figure 2 Figure 3 Introduction Osteoarthritis (OA), a degenerative joint disorder, is a leading cause of musculoskeletal morbidity and disability worldwide. Its prevalence is particularly pronounced in the geriatric population, where knee OA accounts for a substantial proportion of the disease burden ( 1 , 2 ). The quest for an optimal treatment strategy for end-stage knee OA has led to the widespread adoption of total knee arthroplasty (TKA), a procedure that promises to alleviate symptoms and restore joint function. The hallmark of advanced knee OA is often valgus deformity, which is characterized by a complex interplay of anatomical and biomechanical alterations that culminate in pain and functional impairment ( 3 , 4 ). Clinically, the valgus knee is often defined by a hip-knee angle (HKA) > 3° valgus or a femoral-tibial angle (FTA) < 170°.( 5 ) However, the overall incidence of valgus knees in TKA is somewhat lower than that of varum knees( 6 ), and different strategies are suggested for traditional varus knees. Historically, the surgical community has gravitated toward achieving a neutral mechanical alignment (+ 3° to -3°), postulating that this standard ensures an even distribution of joint loads and minimizes implant-related complications ( 7 ). However, the pursuit of this neutral mechanical alignment has not been without its critics, who argue that the one-size-fits-all approach may not account for the individual patient's biomechanical nuances ( 8 , 9 , 10 ). Emerging evidence suggests that a departure from the traditional mechanical alignment paradigm, specifically, maintaining an undercorrected mechanical axis post-TKA, may offer a viable alternative ( 11 , 12 , 13 ). This approach hypothesizes that, with respect to the patient's preexisting biomechanics and soft tissue adaptations, the procedure may enhance patient satisfaction and clinical outcomes ( 8 ). Despite its potential, the outcome of retention of slight post-operative valgus for valgus knees remains unclear. This study aims to analyze the outcomes of TKA for patients with knee valgus deformity and compare the outcomes of different alignment correction strategies in an attempt to clarify whether the retention of slight valgus alignment offers any benefits over neutral alignment in terms of pain relief, functional recovery, and patient-reported satisfaction and survivorship. Patients and methods The study design was a retrospective, double-blinded evaluation that adhered to the ethical principles outlined in the Helsinki Declaration and was approved by the Peking Union Medical College Hospital (PUMCH) Ethics Committee. (IRB: I-24PJ2200) All participants provided informed consent for treatment. Patient selection and grouping Eligible participants were identified from a cohort of patients aged 20–85 years who underwent primary TKA for valgus deformity, defined clinically either by HKA > 3° or FTA < 170°, accompanying primary or secondary knee OA between September 2011 and September 2021 and agreed to join the research. Exclusion criteria were applied to eliminate patients who lost contact and whose data were missing, who had undergone revision surgery before TKA, who had a history of prior open orthopedic surgery, or who had other conditions that could confound the results. ( Fig. 1 ) Patients were then divided into three groups on the basis of postoperative HKA: neutral alignment (NA group) (-3°<HKA 3°) and overcorrection (HKA<-3°). Patients from both groups were divided into 3 groups considering their different follow-up intervals: 3 years of follow-up; 5 years of follow-up; and 10 years of follow-up. Moreover, we separated the patients in both groups into two different degrees (mild and severe) of valgum according to their preoperative HKA (mild valgus knee: 3°<HKA 6°). ( Fig. 2 , 3 ) ( 14 ) Surgical technique All patients underwent primary cemented TKA with a midline incision and the medial para-patellar approach. The tibia cut was performed under an extramedullary guide, whereas the distal femoral cut was performed under an intramedullary guide with a 5°-6° valgus angle. The epicondylar line was used as a reference for rotation of the femoral component. The inside-out release of the soft tissue was applied to each patient to balance the medial and lateral gaps of valgus knees, which usually have a larger medial gap, as well as to achieve the following balance between the flexion and extension gaps, whose aim is to create the same rectangular gap of the knee in both the extension and flexion positions. ( 15 , 16 ) The process first includes the cut of cruciate ligaments, which is determined by the utilization of different protheses: the posterior stabilized (PS) prothesis and the cruciate retention (CR) prothesis.( 17 ) The following steps include the release of the lateral capsule up to the posterior iliotibial band and the eventual release of the iliotibial band via the pie-crusting technique.( 18 ) The release of soft tissue above has always been conducted at the extension position, and the balance of the gaps of extension and flexion may still require further soft tissue release. Moreover, the inside-out strategy releases the soft tissue step by step, but when the gaps between the distal femur and tibial plateau fail to be balanced even with the release of the iliotibial band, the Constrained Condylar Knee (CCK) prosthesis or mid-flexion constrained prosthesis is used. All the patellae were nonresurfaced in this study. Perioperative and postoperative management Intraoperatively, patients received intravenous (i.v.) and topical tranexamic acid (TXA). A prophylactic dose of 1.0 g i.v. TXA was administered prior to tourniquet release to minimize blood loss. Additionally, the surgical site was irrigated with a diluted solution of TXA in saline (1.0 g TXA per liter). For postoperative analgesia, a multimodal approach, including periarticular injections and nonsteroidal anti-inflammatory drug (NSAID)-based multimodal analgesia, was employed. All patients adhered to a standardized rehabilitation protocol. This protocol included the use of continuous passive motion (CPM) to maintain joint mobility, a mechanical booster pump to enhance venous return and reduce the risk of thromboembolic events, and pharmacological anticoagulation treatment to prevent chemical thrombosis. Clinical outcome measures The duration of the operation, strategies for correcting the lower limb axis through modifying the position of patellar or soft tissue release, femoral cut angle differences, various types of implants, soft tissue release conditions, total blood loss, postoperative transfusion volume, and length of hospital stay were recorded by the same doctor. In addition, all the patients underwent preoperative and postoperative blood tests, from which the total blood loss was calculated. The primary TKA was conducted by doctors from the same group, and patient-reported outcome measures (PROMs), including hospital for special surgery knee score (HSS), knee society score (KSS), and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores, were collected. Moreover, the range of motion (ROM) was recorded during the follow-up, and the degree of pain was measured via the visual analog scale (VAS) score of postoperative pain at rest and during movement. An additional investigation was conducted to investigate the patients’ satisfaction with the surgery, which was also evaluated by satisfaction scores (very satisfied: 9–10, satisfied: 7–8, moderate: 5–6, not very satisfied: 3–4, disappointed: 0–2). Furthermore, complications, including intraoperative blood transfusion and infection, were recorded. Moreover, revision surgeries and implant survival rates were recorded. Radiographic assessment The preoperative and postoperative weight-bearing long-leg X-rays and lateral views were collected and measured by the same doctor. The anteroposterior (AP) views were selected, and the hip-knee-angle (HKA) angles were measured. ( 19 , 20 ) Other angles, such as the tibial slope angle (both medial and posterior), mechanical lateral distal femoral angle (mLDFA) and mechanical medial proximal tibial angle (mMPTA), were measured.( 10 , 21 ) Lateral views were used to measure the posterior tibial slope (PTS). Furthermore, to evaluate loosening or infection of the prosthesis, the radiolucent line was measured, and pathological conditions were recorded. ( Fig. 2 , 3 ) ( 22 ) Data analysis All the data were calculated and manipulated with GraphPad Prism 9.5. The data were checked visually for normality via histograms. Continuous variables such as the KSS and HSS scores were recorded as means with 95% confidence intervals (CIs), and their differences were analyzed by t tests. Categorical variables such as the visual analog scale (VAS) score were also recorded as the means with 95% confidence intervals (CIs); however, the results were compared via the Pearson test. P < 0.05 was regarded as significant ( * ), and the number * represents the degree of significance. Results Patient characteristics In this retrospective study, patients who underwent TKA from September 2011 to September 2021 at PUMCH were selected, and 210 patients were selected (36 males and 174 females). According to the inclusion and exclusion criteria, 99 patients and 110 knees were included. We defined a valgus degree greater than 3° as a valgus deformity, categorizing 64 cases as neutral alignment (NA group) and 35 cases as undercorrection alignment. (UA group). Zero patients were found to be overcorrected. The flowchart of patient selection is shown in Fig. 1 . The total average follow-up interval was 5.9 years, while the NA group had 3–10 years of follow-up, with an average of 5.8 years, while the UA group had 3–10 years of follow-up, with an average of 6.2 years, and no significant difference was shown (p = 0.251, according to the t test; p = 0.468, according to the Pearson test). The demographic characteristics and clinical classifications were not significantly different between the two groups. The detailed data are shown in Table 1 . Table 1 Baseline data for knees with neutral alignment and undercorrection alignment. Characteristics Neutral alignment group Undercorrection alignment group p -value Age (yrs.) 64.95 (61.96–67.95) 64.23 (59.78–68.68) 0.7805 Obesity (n) # 9 2 0.2104 BMI (kg/m 2 ) 25.69 (24.66–26.72) 24.60 (23.56–25.65) 0.1727 Sex (male/female) # 14/50 4/31 0.2015 Follow-up interval(years) 5.756 (5.273–6.239) 6.225 (5.565–6.886) 0.2506 Follow-up groups# / / 0.4679 3 years follow-up 14 5 / 5 years follow-up 42 23 / 10 years follow-up 8 7 / Operation side(s) # Left Right Double 18 41 5 10 19 6 0.3445 Pre-operative osteoporosis # 23 9 0.3033 ASA classification (n) # Grade I Grade II Grade III Grade IV-VI 3 40 21 0 6 18 11 0 0.1137 KL classification (n) # Grade I-II Grade III Grade IV 0 38 31 0 22 19 0.8855 BMI, body mass index; ASA, American society of Aneshesiologists; K-L, Kellgren-Lawrence. Values are mean (95% CI range) unless otherwise specified with #. Surgical-related outcomes The surgery-related outcomes are shown in Table 2 and include the angle of the femur cut, type of prosthesis (PS, CR or Constrained Condylar Knee (CCK) prosthesis), soft tissue release, length of hospital stay after the operation, duration of the operation, and total blood loss. There were no significant differences between the angles of the distal femur cut during the operation (p = 0.643) and the angle of implant selection (p = 0.265). Moreover, other surgical-related information, such as the length of hospitalization (p = 0.734), duration of operation (p = 0.231) and total blood loss (p = 0.117), did not significantly differ between the two groups. The soft tissues most commonly released in the valgus knee during the TKA procedure were the posterolateral articular capsule and iliotibial tract band in this study. The lateral collateral ligament was also released in 9 patients in total (6 in the NA group and 3 in the UA group). There were no differences in the release frequencies of all three ligaments (p = 0.908): the posterolateral articular capsule (p = 0.451), iliotibial tract band (p = 0.654), or lateral collateral ligament (p = 0.844). Table 2 Surgical related outcomes for knees with neutral alignment and undercorrection alignment. Surgical outcomes Neutral alignment group Undercorrection alignment group p -value Femur cut angle 5.422 (5.290–5.554) 5.371 (5.203–5.540) 0.6427 Types of prothesis / / 0.2650 PS# 64 (91.43%) 33 (82.50%) / CR# 4 (5.714%) 6 (15.00%) / CCK# 2 (2.857%) 1 (2.50%) / Release of soft tissue / / 0.9078 Posterolateral articular capsule# 23 (32.85%) 16 (40.00%) 0.4513 Iliotibial tract band# 10 (14.29%) 7 (27.50%) 0.6537 Lateral collateral ligament# 6 (8.57%) 3 (7.50%) 0.8437 Length of stay after operation (days) 6.828 (5.819–7.838) 7.229 (5.916–8.541) 0.7336 Duration of operation (min) 108.0 (98.30-117.7) 117.3 (101.4-133.1) 0.2922 Total blood loss (mL) 806.2 (710.9-901.5) 769.7 (608.7-930.7) 0.1167 PS, posterior stabilized; CR, cruciate retention; CCK, Constrained Condylar Knee prothesis. Values are mean (95% CI range) unless otherwise specified with #. Clinical outcomes The clinical outcomes are presented in Table 3 . There were no statistically significant differences in postoperative outcome scores, including the KSS knee score (p = 0.570), KSS function score (p = 0.227), HSS score (p = 0.467), WOMAC pain score (p = 0.404), WOMAC function score (p = 0.283), WOMAC stiffness score (p = 0.592), or WOMAC total score (p = 0.391), between the NA group and UA group. The ROM (p = 0.939) also resembled that in both groups, with a mean of 129.0 degrees in the NA group and 128.7 degrees in the UA group. ( Table 4 ) There was no difference in the postoperative VAS pain score at rest (the average score of the NA group: the UA group 0.72: 1.2) (p = 0.227) or during movement (1.4: 1.9) (p = 0.266) between the UA group and the NA group. The patients were separated into different groups according to their satisfaction levels. The percentages of the very satisfied group in the NA group and the UA group were 54.7% and 42.9%, respectively, whereas the percentages of the satisfied group were 37.5% and 37.1%, moderate 3.1% and 8.6%, not very satisfied 4.7% and 5.7%, disappointing 0% and 5.7%, respectively. Generally, there was no difference in the satisfaction rate (p = 0.226) between the two groups according to the Pearson test, and detailed satisfaction grouping data are recorded in Table 4 . Table 3 Clinical scores for knees with neutral alignment and undercorrection alignment. Clinical scores Neutral alignment group Undercorrection alignment group p -value KSS knee score 86.80 (82.91–90.69) 84.71 (77.74–91.68) 0.5698 KSS function score 89.92 (86.42–93.42) 85.43 (77.62–93.24) 0.2267 HSS score 87.73 (84.46–91.01) 85.23 (78.01–92.45) 0.4671 WOMAC Pain score 1.641 (1.156–2.125) 2.143 (0.7609–3.525) 0.4037 WOMAC function score 3.266 (2.254–4.277) 4.457 (2.068–6.846) 0.2833 WOMAC stiffness score 0.7500 (0.4756–1.024) 0.6286 (0.2743–0.9829) 0.5924 WOMAC total score 5.656 (3.994–7.319) 7.229 (3.267–11.19) 0.3912 ROM ( ° ) 129.0 (124.0-134.0) 128.7 (122.4–135.0) 0.9386 KSS, knee society score; HSS, hospital for special surgery knee score; WOMAC, Western Ontario and McMaster University Osteoarthritis Index; ROM, range of motion. Values are mean (95% CI range) unless otherwise specified with #. Table 4 WOMAC Pain score and Satisfaction VAS scores for knees with neutral alignment and undercorrection alignment. Clinical scores Neutral alignment group Undercorrection alignment group p -value Pain at rest 0.7188 (0.4026–1.035) 1.171 (0.3321–2.011) 0.2267 Pain at movement 1.375 (0.8646–1.885) 1.886 (1.066–2.705) 0.2656 Satisfaction / / 0.2259 Very satisfied# 35 (54.69%) 15 (42.86%) / Satisfied# 24 (37.50%) 13 (37.14%) / Moderate# 2 (3.125%) 3 (8.571%) / Not very satisfied# 3 (4.688%) 2 (5.714%) / Disappointed# 0 (0%) 2 (5.714%) / WOMAC, Western Ontario and McMaster University Osteoarthritis Index; VAS, visual analog scale. Values are mean (95% CI range) unless otherwise specified with #. Radiographic results The radiographic outcomes, which were mainly the preoperative and postoperative HKA, are presented in Table 5 . There were also no clear differences in the preoperative HKA between the NA group and the undercorrection alignment group (means: 11.2 ° and 9.9 °, respectively; p = 0.131). The results of further grouping of mild and severe valgus knees also revealed no significant difference (p = 0.211), with 6 patients in the mild valgus group and 58 in the severe valgus group in the NA group and 7 patients in the mild valgus group and 28 in the severe valgus group in the UA group. However, there was a significantly larger postoperative HKA in the UA group (p < 0.0001, **** ), the mean of which was 6.3 ° compared with the 1.2 ° in the NA group. Moreover, the medial and posterior tibial slope angles, mLDFA and mMPTA are also recorded in Table 5 . No significant differences were found in the preoperative medial tibial slope angles, mLDFA or mMPTA (NA group: 2.1 ° (1.0–3.2 ° ); 83.0 ° (82.0–84.0 ° ); 88.0 ° (86.9–89.1 ° ); UA group: 1.1 ° (-0.3–2.4 ° ); 83.4 ° (81.3–85.5 ° ); 88.9 ° (87.6–90.3 ° ), and p = 0.282; 0.705–0.289, respectively). However, the postoperative mLDFA of the undercorrection group (86 ° .9 ° (85.9 ° -88.0 ° )) was much lower than that of the NA group (89.19 ° (88.8 ° -89.6 ° )) (p < 0.0001, **** ), whereas the mMPTA was significantly greater (90.5 ° (89.8 ° -91.2 ° ): 89.6 ° (89.2 ° -90.1 ° ) for the undercorrection group and the NA group, respectively; p = 0.034, * ). Since the postoperative mMPTA of the two groups was approximately 90 degrees, the remaining valgum in the UA group was confirmed to be based mainly on undercorrection of the distal femur. In addition, the tibial plateau of the UA group tilted laterally (-0.5 ° (-1.2 ° -0.2 ° )) after surgery, whereas that of the NA group tilted slightly to the medial side (0.4 ° (-0.08 ° -0.8 ° )). This significant difference (p = 0.038) might also contribute to the remaining deformity. Other postoperative angles were not significantly different. ( Table 5 ) Finally, no pathological radiolucent line was recorded in any of the patients, indicating that no cases of implant loosening or infection occurred. Table 5 Radiographic outcomes for knees with neutral alignment and undercorrection alignment. Radiographic outcomes Neutral alignment group Undercorrection alignment group p -value HKA Pre-operative HKA ( ° ) 11.22 (10.26–12.18) 9.914 (8.368–11.46) 0.1314 Groups: 0.2114 Mild valgus knee 6 7 Severe valgus knee 58 28 Post-operative HKA ( ° ) 1.219 (0.9081–1.529) 6.286 (5.711–6.860) < 0.0001 Medial tibial slope angle Pre-operative medial tibial slope angle ( ° ) 2.059 (0.9564–3.161) 1.076 (-0.2563-2.409) 0.2822 Post-operative medial tibial slope angle ( ° ) 0.3529 (-0.08119-0.7871) -0.4771 (-1.196-0.2412) 0.0381 Posterior lateral tibial slope angle Pre-operative posterior tibial slope angle ( ° ) 8.032 (6.740–9.324) 6.261 (4.298–8.225) 0.1169 Post-operative lateral posterior tibial slope angle ( ° ) 4.034 (3.268–4.801) 4.263 (3.107–5.418) 0.7487 mLDFA Pre-operative mLDFA ( ° ) 83.01 (82.03-84.00) 83.39 (81.33–85.46) 0.7053 Post-operative mLDFA ( ° ) 89.19 (88.80-89.58) 86.90 (85.85–87.95) < 0.0001 mMPTA Pre-operative mMPTA ( ° ) 87.96 (86.86–89.06) 88.92 (87.59–90.26) 0.2886 Post-operative mMPTA ( ° ) 89.63 (89.20-90.06) 90.48 (89.76–91.20) 0.0335 Pathological radiolucent line# 0 0 / HKA, hip-knee-angle; mLDFA, mechanical lateral distal femoral angle; mMPTA, mechanical medial proximal tibial angle. Values are mean (95% CI range) unless otherwise specified with #. Positive values refer to valgus angles. Complications As shown in Table 6 , generally, no significant differences were detected between the two groups (p = 0.555). Moreover, the most common complication after TKA is deep venous thrombosis in the lower extremities. Thrombosis occurs in approximately 2.0% of patients who undergo TKA even with antithrombosis strategies.( 23 ) The percentages of deep venous thrombosis in both groups were 3.1 and 2.9%, respectively, which were not significantly different (p = 0.915). Peroneal nerve injury is also considered to be related to the release of lateral ligaments during TKA.( 4 ) However, no patients experienced such injuries. None of the patients in either group underwent revision surgery after their primary TKA, representing 100% survival of the implants. However, there were more types of complications in the NA group. Table 6 Post-operative complications and survivorship for knees with neutral alignment and undercorrection alignment. Complications# Neutral alignment group Undercorrection alignment group p -value Deep venous thrombosis 4 2 0.9150 Blood intravenous infusion 2 1 0.9407 Osteoporosis 1 2 0.2493 Lung nodule 2 0 0.2907 Prothesis infection 1 0 0.4573 Periprosthetic fractures 1 0 0.4573 Patella Baja 1 0 0.4573 Lower lobe pulmonary bulla 1 0 0.4573 Renal cyst 1 0 0.4573 Cystic density lesion in the adnexal region 1 0 0.4573 Hyperuricemia 1 0 0.4573 Coronary artery plaque formation 1 0 0.4573 Chronic otitis media 1 0 0.4573 Hyperlipidemia 1 0 0.4573 Chronic superficial gastritis 1 0 0.4573 Diabetes 0 1 0.1741 Urinary tract infection 0 1 0.1741 Rosacea 0 1 0.1741 Thyroid nodule 0 1 0.1741 Implant failure 0 0 / Values are mean (95% CI range) unless otherwise specified with #. Discussion Since neutral mechanical alignment has long been considered the best treatment and remains the trending method, other methods for TKA, such as anatomical or kinematic alignment, which retains the varum, have also been reported to provide good results.( 24 ) However, the results of the remaining volume after TKA have rarely been reported, which makes the current research necessary to obtain a complete review of TKA prognosis. The current research focused mainly on the prognosis between TKA with a neutral alignment and the valgum remaining strategy. Primarily, the resemblance of the recovery time in hospitals between the two strategies showed no clear difference. The detailed data revealed that there were no significant changes in the PROMs between the NA group and the UA group, indicating that the functional recovery of the two groups was associated with comparable outcomes. The lack of significant variation in the ROM results also demonstrated a similar functional prognosis. Radiographic results revealed that the preoperative angles of the lower limb axis did not vary significantly, whereas the postoperative mLDFA deviated more from the neutral alignment (90°) in the UA group, indicating that the undercorrection of the valgus knee was usually caused by the remaining deformity at the femur site. It has long been recognized that varus deformities of the tibia can induce implant failure. ( 25 ) However, in 2023, Luyckx et al reported that when the femoral component was placed in > 3° of valgus (mLDFA < 87°), the survival of the implant significantly (p = 0.003) decreased over 12.9 years of follow-up, whereas the alignment of the tibia had a minor effect (p = 0.855).( 26 ) However, in our research, no survival difference was recorded due to the differences in mLDFA. The contradictions in survival might be attributed to the shorter interval of follow-up and different surgical strategies. Moreover, in the NA group, the operation significantly decreased the PTS (p < 0.0001, **** ), whereas in the UA group, it did not (p = 0.065). These findings revealed that, in the undercorrection group, osteotomy was not sufficient to change the original deformity, and similar clinical outcomes were achieved. PTS has been reported to be crucial for the stability of knee joints, the reduction of which could decrease the possibility of implant failure in anterior cruciate ligament reconstruction operations.( 27 ) However, considering the similar results of the PROMs of the patients in this study, the patients seemed to be accustomed to the deformity, which mightpotentially lead to less loss of bone mass in future surgeries. In addition, the results were consistent with those of previous studies; more postoperative radiographic angles were compared by Lee et al.( 14 ), who reported no significant differences between the conventional method and the valgum-remaining strategy. Patient satisfaction has been regarded as crucial for defining whether TKA is successful. Various factors are considered to affect the satisfaction of patients, including the type of prosthesis,( 28 ) PROMs,( 29 ) occurrence of complications( 23 ) and postoperative rehabilitation process.( 30 ) In this study, there was no difference in the factors above, resulting in similar levels of satisfaction between the two groups. However, an F test was further conducted to compare the variances between the two groups and revealed significant differences (p = 0.0011, ** ), revealing much greater standard variance in the UA group (2.390) than in the NA group (1.489), which might reveal that a strategy aimed at neutral alignment could lead to more stable outcomes. Finally, gait alternations could also be included in the prognosis of TKA since it was reported that gait was associated with feelings of pain and the type of prosthesis. Generally, TKA relieves pain and improves gait performance.( 31 ) Recently, Fukui et al( 32 ) examined gait alternations with a Walkway analyzer, a sheet-type gait analyzer, and reported that after unilateral TKA, the time indices, stance phase, and double-limb support phase time, which were shorter on the affected side, whereas the swing phase, which was longer on the affected side, normalized after the operation. Moreover, the different outcomes of gait after TKA due to different types of prostheses and the combination of ankle arthritis have also been reported, suggesting that different strategies of TKA might result in various gaits.( 28 , 33 ) Nevertheless, whether the remaining valgum affects gait compared with the neutral alignment has not been fully researched, and more studies could be performed to compare the two strategies of TKA. The traditional mechanical alignment remains the gold standard for reducing damage to the implant by ensuring equal distribution of loads between the medial and lateral compartments of the knee and thus alleviating the shear forces between the implants and bone.( 34 ) Moreover, in contrast to the method of remaining varum, which is based mainly on kinematic or anatomical alignment, the retention of valgum is not based on the constituted anatomic varum of the tibio-femoral alignment; the purpose of retaining the valgum could be attributed to the severity of the preoperative valgum,( 35 ) and other reasons remain to be researched. However, according to the follow-up results, the prognosis did not differ clearly between the anatomic alignment technique and the valgum-remaining technique. The discomfort of patients after TKA is considered to be caused mainly by implant loosening or failure. Neutral alignment has been reported to reduce the asymmetric bearing wear of implants, which can potentially increase the survival rate of the prosthesis.( 8 ) However, more detailed research revealed that the failure rate in knees with varus alignment was significantly greater than that in knees with neutral alignment (p = 0.02), whereas no significant difference was detected in the survival rates of patients with valgus malalignment and neutral alignment.( 36 ) No revision surgeries were performed after the last TKA in either group in this research; thus, a longer follow-up time might be necessary. Furthermore, the relationship between the level of undercorrection and the degree of implant failure remains unclear. More studies are needed to evaluate the survival of implants in patients with different degrees of valgum remaining. Additionally, since only a few patients with severe valgum had HKA values greater than 20°, both the NA group and UA group had severe valgum values. The prognosis of TKA patients has yet to be fully reported, and it is difficult to propose a proper treatment strategy. In addition, soft tissue release is the most commonly used method to correct the lower limb axis and create proper gaps between bones. For the correction of valgus knees, the release of the lateral ligaments, including the iliotibial tract band or the lateral collateral ligament, and the posterolateral articular capsule and constriction of the medial ligament, such as the medial collateral ligament, have all been reported to be efficient.( 37 , 38 ) Nevertheless, there are alternations in the previous joint line, which patients are likely accustomed to due to prolonged reformation of soft tissue.( 39 ) A multicenter study conducted by Vigdorchik et al.( 40 ) also revealed that additional release of soft tissue would also lead to a worse prognosis. However, in this study, no significant difference in the release of lateral soft tissues was recorded, which might be the potential reason for the similar outcomes. Further studies can be conducted to create better designs for TKA. Currently, the Coronal Plane Alignment of the Knee (CPAK) classification is widely used to generate more detailed categories of knee deformations. The conventional definition for the valgus knee is related to the HKA when HKA > 3° is considered the knee valgum. However, the CPAK standard separates the valgus knee into 3 detailed groups considering the different joint line obliquity (JLO) values (mMPTA + mLDFA). When the mMPTA + mLDFA is greater than 180°, it is called the apex proximal deformity, whereas when the mMPTA + mLDFA is less than 180°, it is called the apex distal deformity. Thus, the knee valgum is categorized into 3 groups, namely, CPAK III (valgum combining apex distal), VI (valgum with neutral JLO) and IX (valgum combining apex proximal).( 10 ) For different CPAK types of valgus, different TKA strategies, including mechanical alignment and kinetic alignment, can yield various outcomes, and the optimal choices for each type of valgum vary, similar to the differences in survivorship mentioned previously.( 26 ) Even though, generally, the mMPTA and mLDFA were elevated significantly after surgery (NA group: p mMPTA =0.0053, ** ; p mLDFA <0.0001, **** ; UA group: p mMPTA = 0.0392, * ; p mLDFA = 0.0028, ** ), the majorly altered angles in different patients varied. Furthermore, we assumed that for the undercorrection alignment strategy, there should be different optimal valgus angles as well as the mMPTA and mLDFA for different patients; however, no specific research has been conducted to identify exact strategies. Finally, since the robotic operation strategy is now prevalent and still in need of modification to achieve the best result, as the previous standard was to be as accurate as possible to achieve mechanical alignment, which was found to be not suitable for all patients,( 41 ) this research might contribute to the development of more flexible criteria for judgment of the section angle during robotic operation.( 8 ) Nevertheless, there are still many limitations that need improvement in this research. More patients can be included in our studies, and longer-term follow-up is needed to assess outcomes over a longer period. Moreover, the number of included cases was limited, and complex cases were not included. Randomized controlled trials (RCTs) are needed in the future. Finally, no further investigations of the mechanisms of the influence of valgus deformity on patients were carried out in this study, which is also needed in the future. Conclusion This study revealed no significant differences in postoperative outcomes between TKA patients with conventional mechanical alignment and those with slight valgus retention. This finding suggests that retaining slight valgus with an average angle of 6.3° may not compromise the success of TKA and could offer an alternative standard for surgical planning. Declarations Ethics statement This study was reviewed and approved by Peking Union Medical College Hospital and the Peking Union Medical College Hospital Ethics Committee. (IRB: I-24PJ2200) All participants provided informed consent for treatment. The patients provided written informed consent to participate in this study. Written informed consent was obtained from the individuals for the publication of any potentially identifiable images or data included in this article. Consent to Publish Consent to publication was obtained from the participants. Clinical trial number Not applicable. Conflict of interest All the authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or nonfinancial interest in the subject matter or materials discussed in this manuscript. Funding Not applicable. Author Contribution This work was designed by Xisheng Weng and Bin Feng. The procedures were performed by Xisheng Weng and Bin Feng. The data were collected by Runze Zhou and Hanyang Sun. The data were analyzed by Runze Zhou, Yixin Bian and Zhanqi Wei. This manuscript was written by Runze Zhou and Zhanqi Wei. All the authors approved the final version. Data availability statement The original contributions presented in the study are included in the article. Further inquiries can be directed to the corresponding author. 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Clin Orthop Relat Res. 1986(205) Luyckx T, Moreels R, Geernaert H, Scheys L, Vandenneucker H (2023) Valgus alignment of the femoral component is associated with higher revision rates 10 years after TKA. Knee Surg Sports Traumatol Arthrosc 31(10):4171–4178 Onishi S, Kim Y, Nakayama H, Mansour AA 3rd, Lowe WR, Ollivier M (2024) Infratubercle Anterior Closing Wedge Osteotomy Corrects Sagittal Alignment without Affecting Coronal Alignment or Patellar Height. J Clin Med. ;13(16) Dorr LD, Ochsner JL, Gronley J, Perry J (1988) Functional comparison of posterior cruciate-retained versus cruciate-sacrificed total knee arthroplasty. Clin Orthop Relat Res. (236):36–43 Blackburn AZ, Feder O, Amakiri I, Melnic CM, Huddleston JI, Malchau H et al (2024) One-Year Postoperative Patient-Reported Outcome Measures Are Associated With Three-Year to Five-Year Postoperative Satisfaction in Total Knee Arthroplasty. J Arthroplasty 39(3):683–688 Jiao S, Feng Z, Dai T, Huang J, Liu R, Meng Q (2024) High-Intensity Progressive Rehabilitation Versus Routine Rehabilitation After Total Knee Arthroplasty: A Randomized Controlled Trial. J Arthroplasty. ;39(3) Kroll MA, Otis JC, Sculco TP, Lee AC, Paget SA, Bruckenstein R et al (1989) The relationship of stride characteristics to pain before and after total knee arthroplasty. Clin Orthop Relat Res. (239):191–195 Fukui J, Matsui Y, Mizuno T, Watanabe T, Takemura M, Ishizuka S et al (2024) Comparison of gait analysis before and after unilateral total knee arthroplasty for knee osteoarthritis. J Orthop Surg Res 19(1):506 Kikuchi N, Kanamori A, Kadone H, Okuno K, Hyodo K, Yamazaki M (2024) Varus knee osteoarthritis with ankle osteoarthritis demonstrates greater hindfoot inversion and larger ankle inversion loading during gait following total knee arthroplasty compared to varus knee osteoarthritis alone. Knee Surg Sports Traumatol Arthrosc 32(9):2309–2317 Aunan E, Röhrl SM (2018) No detrimental effect of ligament balancing on functional outcome after total knee arthroplasty: a prospective cohort study on 129 mechanically aligned knees with 3 years' follow-up. Acta Orthop 89(5):548–554 Tian F, Zang XH, Sun YS (2018) Impact of knee varus and valgus deformity on alignment in lower extremities after total knee arthroplasty (TKA). Eur Rev Med Pharmacol Sci 22(1 Suppl):83–89 Liu H-X, Shang P, Ying X-Z, Zhang Y (2016) Shorter survival rate in varus-aligned knees after total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 24(8):2663–2671 Whiteside LA (1993) Correction of ligament and bone defects in total arthroplasty of the severely valgus knee. Clin Orthop Relat Res. (288):234–245 Krackow KA, Jones MM, Teeny SM, Hungerford DS Primary total knee arthroplasty in patients with fixed valgus deformity. Clin Orthop Relat Res. 1991(273). Victor JMK, Bassens D, Bellemans J, Gürsu S, Dhollander AAM, Verdonk PCM (2014) Constitutional varus does not affect joint line orientation in the coronal plane. Clin Orthop Relat Res. ;472(1) Vigdorchik JM, Wakelin EA, Koenig JA, Ponder CE, Plaskos C, DeClaire JH et al (2022) Impact of Component Alignment and Soft Tissue Release on 2-Year Outcomes in Total Knee Arthroplasty. J Arthroplasty. ;37(10) Drexler M, Abolghasemian M, Barbuto R, Naini MS, Voshmeh N, Rutenberg TF et al (2017) Patient's Height and Hip Medial Offset Are the Main Determinants of the Valgus Cut Angle During Total Knee Arthroplasty. J Arthroplasty 32(5):1496–1501 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7329372","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":504185899,"identity":"896bd006-65bb-4d3c-8136-9f0824432978","order_by":0,"name":"Runze Zhou","email":"","orcid":"","institution":"Chinese Academy of Medical Sciences and Peking Union Medical College","correspondingAuthor":false,"prefix":"","firstName":"Runze","middleName":"","lastName":"Zhou","suffix":""},{"id":504185900,"identity":"5df21021-2627-4399-8549-619edac5f42c","order_by":1,"name":"Hanyang Sun","email":"","orcid":"","institution":"Chinese Academy of Medical Sciences and Peking Union Medical College","correspondingAuthor":false,"prefix":"","firstName":"Hanyang","middleName":"","lastName":"Sun","suffix":""},{"id":504185901,"identity":"f45ca183-2963-4d23-b2f9-6b8184c5f83a","order_by":2,"name":"Zhanqi Wei","email":"","orcid":"","institution":"Sun Yat-sen University","correspondingAuthor":false,"prefix":"","firstName":"Zhanqi","middleName":"","lastName":"Wei","suffix":""},{"id":504185902,"identity":"20a5566d-6935-45c3-a6a9-4f0f278ef967","order_by":3,"name":"Yixin Bian","email":"","orcid":"","institution":"Chinese Academy of Medical Sciences and Peking Union Medical College","correspondingAuthor":false,"prefix":"","firstName":"Yixin","middleName":"","lastName":"Bian","suffix":""},{"id":504185903,"identity":"2fb91da8-754f-46a6-9f63-525e039b5646","order_by":4,"name":"Wei Zhu","email":"","orcid":"","institution":"Chinese Academy of Medical Sciences and Peking Union Medical College","correspondingAuthor":false,"prefix":"","firstName":"Wei","middleName":"","lastName":"Zhu","suffix":""},{"id":504185904,"identity":"6685f152-5089-4426-81ba-b56f6813a004","order_by":5,"name":"Bin Feng","email":"","orcid":"","institution":"Chinese Academy of Medical Sciences and Peking Union Medical College","correspondingAuthor":false,"prefix":"","firstName":"Bin","middleName":"","lastName":"Feng","suffix":""},{"id":504185905,"identity":"3cf05b13-0c4f-4c20-8847-ca03fbe48f35","order_by":6,"name":"Xisheng Weng","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAxklEQVRIiWNgGAWjYDCCA1DagL2x8eEH0rTwHG42liBNi0R6mwAPMTr4bp8xfFzw67C9ueTDNgYJBjs53QYCWiTP5Rgbz+xLS9w5O7HtQQFDsrHZAQJaDM7wbpPm7bFJMLid2G4gwXAgcRsRWrb/5u2RsDe4ebBNgodILduYeX7YMG64wUikFskz/J+leRvSEjecSQQGsgERfuE7w5b4mefPYXuD48cfPvxQYSdHUAsYMLbB3UmMcjD4Q7TKUTAKRsEoGIkAAF/VRYBkX7ugAAAAAElFTkSuQmCC","orcid":"","institution":"Chinese Academy of Medical Sciences and Peking Union Medical College","correspondingAuthor":true,"prefix":"","firstName":"Xisheng","middleName":"","lastName":"Weng","suffix":""}],"badges":[],"createdAt":"2025-08-08 17:23:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7329372/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7329372/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":90380557,"identity":"aaa2a702-e321-41a1-9f60-7be3df622d9f","added_by":"auto","created_at":"2025-09-02 06:44:14","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":165691,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart of the study.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7329372/v1/e82a38c458543c6da18313a8.png"},{"id":90382247,"identity":"7967eb34-c4d5-4375-84b7-8e567854ae1e","added_by":"auto","created_at":"2025-09-02 06:52:14","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":405964,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea) \u003c/strong\u003ePreoperative and postoperativeX-rays of the TKA with neutral alignment with the HKA; the medial tibial slope (between the red and adjacent white solid lines and slope toward the medial side was considered positive), mLDFA and mMPTA of each operated knee are marked. i) Preoperative, HKA=15°, medial tibial slope=-2°, mLDFA=79°, mMPTA=92°;ii) postoperative, HKA=2°, medial tibial slope=-2°, mLDFA=92°, mMPTA=92°. The red solid line shows the line perpendicular to the tibial anatomic axis. \u003cstrong\u003eb)\u003c/strong\u003e Preoperative and postoperativeX-rays of the TKA with neutral alignment with the PTS: i) preoperative PTS= 7° and ii) postoperativePTS= 0°. (The blacksolid line shows the line perpendicular to the tibial anatomic axis.)\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7329372/v1/844956a44add97c658761dff.png"},{"id":90383506,"identity":"51eb12b3-e70a-41f5-8d98-9176525277cf","added_by":"auto","created_at":"2025-09-02 07:00:14","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":508958,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea) \u003c/strong\u003ePreoperative and postoperativeX-rays of the TKA with undercorrection alignment with the HKA; the medial tibial slope (between the red and adjacent white solid lines and slope toward the medial side was considered positive), mLDFA and mMPTA of each operated knee are marked. i) Preoperative, HKA=12°; medial tibial slope=1°; mLDFA=79°; mMPTA=89°; ii) postoperative, HKA=9°; medial tibial slope=-4°; mLDFA=87°; mMPTA=94°. The red solid line shows the line perpendicular to the tibial anatomic axis. \u003cstrong\u003eb) \u003c/strong\u003ePreoperative and postoperative X-rays taken duringTKA with undercorrection alignment with the PTS. i) Preoperative PTS= 6°. ii) Postoperative PTS= 6°. (The black solid line shows the line perpendicular to the tibial anatomic axis.)\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7329372/v1/d6b64b12f257f1018f6cc6d1.png"},{"id":94474337,"identity":"4810a814-07fe-4c43-9464-db2ce1642ecd","added_by":"auto","created_at":"2025-10-27 15:48:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2074288,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7329372/v1/98c0abfb-ce78-4b14-9ff4-f63bc3c1d1bd.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Valgus Considered: Redefining Total Knee Arthroplasty Alignment for Optimal Patient Outcomes","fulltext":[{"header":"Introduction","content":"\u003cp\u003eOsteoarthritis (OA), a degenerative joint disorder, is a leading cause of musculoskeletal morbidity and disability worldwide. Its prevalence is particularly pronounced in the geriatric population, where knee OA accounts for a substantial proportion of the disease burden (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). The quest for an optimal treatment strategy for end-stage knee OA has led to the widespread adoption of total knee arthroplasty (TKA), a procedure that promises to alleviate symptoms and restore joint function. The hallmark of advanced knee OA is often valgus deformity, which is characterized by a complex interplay of anatomical and biomechanical alterations that culminate in pain and functional impairment (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Clinically, the valgus knee is often defined by a hip-knee angle (HKA)\u0026thinsp;\u0026gt;\u0026thinsp;3\u0026deg; valgus or a femoral-tibial angle (FTA)\u0026thinsp;\u0026lt;\u0026thinsp;170\u0026deg;.(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e) However, the overall incidence of valgus knees in TKA is somewhat lower than that of varum knees(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e), and different strategies are suggested for traditional varus knees.\u003c/p\u003e\u003cp\u003eHistorically, the surgical community has gravitated toward achieving a neutral mechanical alignment (+\u0026thinsp;3\u0026deg; to -3\u0026deg;), postulating that this standard ensures an even distribution of joint loads and minimizes implant-related complications (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). However, the pursuit of this neutral mechanical alignment has not been without its critics, who argue that the one-size-fits-all approach may not account for the individual patient's biomechanical nuances (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eEmerging evidence suggests that a departure from the traditional mechanical alignment paradigm, specifically, maintaining an undercorrected mechanical axis post-TKA, may offer a viable alternative (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). This approach hypothesizes that, with respect to the patient's preexisting biomechanics and soft tissue adaptations, the procedure may enhance patient satisfaction and clinical outcomes (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Despite its potential, the outcome of retention of slight post-operative valgus for valgus knees remains unclear.\u003c/p\u003e\u003cp\u003eThis study aims to analyze the outcomes of TKA for patients with knee valgus deformity and compare the outcomes of different alignment correction strategies in an attempt to clarify whether the retention of slight valgus alignment offers any benefits over neutral alignment in terms of pain relief, functional recovery, and patient-reported satisfaction and survivorship.\u003c/p\u003e"},{"header":"Patients and methods","content":"\u003cp\u003e The study design was a retrospective, double-blinded evaluation that adhered to the ethical principles outlined in the Helsinki Declaration and was approved by the Peking Union Medical College Hospital (PUMCH) Ethics Committee. (IRB: I-24PJ2200) All participants provided informed consent for treatment.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003ePatient selection and grouping\u003c/h2\u003e\u003cp\u003eEligible participants were identified from a cohort of patients aged 20\u0026ndash;85 years who underwent primary TKA for valgus deformity, defined clinically either by HKA\u0026thinsp;\u0026gt;\u0026thinsp;3\u0026deg; or FTA\u0026thinsp;\u0026lt;\u0026thinsp;170\u0026deg;, accompanying primary or secondary knee OA between September 2011 and September 2021 and agreed to join the research. Exclusion criteria were applied to eliminate patients who lost contact and whose data were missing, who had undergone revision surgery before TKA, who had a history of prior open orthopedic surgery, or who had other conditions that could confound the results. \u003cb\u003e(\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e Patients were then divided into three groups on the basis of postoperative HKA: neutral alignment (NA group) (-3\u0026deg;\u0026lt;HKA\u0026thinsp;\u0026lt;\u0026thinsp;3\u0026deg;), undercorrection alignment (UA group) (HKA\u0026thinsp;\u0026gt;\u0026thinsp;3\u0026deg;) and overcorrection (HKA\u0026lt;-3\u0026deg;). Patients from both groups were divided into 3 groups considering their different follow-up intervals: 3 years of follow-up; 5 years of follow-up; and 10 years of follow-up. Moreover, we separated the patients in both groups into two different degrees (mild and severe) of valgum according to their preoperative HKA (mild valgus knee: 3\u0026deg;\u0026lt;HKA\u0026thinsp;\u0026lt;\u0026thinsp;6\u0026deg;; severe valgus knee: HKA\u0026thinsp;\u0026gt;\u0026thinsp;6\u0026deg;). \u003cb\u003e(\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e,\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e)\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eSurgical technique\u003c/h3\u003e\n\u003cp\u003eAll patients underwent primary cemented TKA with a midline incision and the medial para-patellar approach. The tibia cut was performed under an extramedullary guide, whereas the distal femoral cut was performed under an intramedullary guide with a 5\u0026deg;-6\u0026deg; valgus angle. The epicondylar line was used as a reference for rotation of the femoral component.\u003c/p\u003e\u003cp\u003eThe inside-out release of the soft tissue was applied to each patient to balance the medial and lateral gaps of valgus knees, which usually have a larger medial gap, as well as to achieve the following balance between the flexion and extension gaps, whose aim is to create the same rectangular gap of the knee in both the extension and flexion positions. (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e) The process first includes the cut of cruciate ligaments, which is determined by the utilization of different protheses: the posterior stabilized (PS) prothesis and the cruciate retention (CR) prothesis.(\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e) The following steps include the release of the lateral capsule up to the posterior iliotibial band and the eventual release of the iliotibial band via the pie-crusting technique.(\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e) The release of soft tissue above has always been conducted at the extension position, and the balance of the gaps of extension and flexion may still require further soft tissue release. Moreover, the inside-out strategy releases the soft tissue step by step, but when the gaps between the distal femur and tibial plateau fail to be balanced even with the release of the iliotibial band, the Constrained Condylar Knee (CCK) prosthesis or mid-flexion constrained prosthesis is used. All the patellae were nonresurfaced in this study.\u003c/p\u003e\n\u003ch3\u003ePerioperative and postoperative management\u003c/h3\u003e\n\u003cp\u003eIntraoperatively, patients received intravenous (i.v.) and topical tranexamic acid (TXA). A prophylactic dose of 1.0 g i.v. TXA was administered prior to tourniquet release to minimize blood loss. Additionally, the surgical site was irrigated with a diluted solution of TXA in saline (1.0 g TXA per liter). For postoperative analgesia, a multimodal approach, including periarticular injections and nonsteroidal anti-inflammatory drug (NSAID)-based multimodal analgesia, was employed.\u003c/p\u003e\u003cp\u003eAll patients adhered to a standardized rehabilitation protocol. This protocol included the use of continuous passive motion (CPM) to maintain joint mobility, a mechanical booster pump to enhance venous return and reduce the risk of thromboembolic events, and pharmacological anticoagulation treatment to prevent chemical thrombosis.\u003c/p\u003e\n\u003ch3\u003eClinical outcome measures\u003c/h3\u003e\n\u003cp\u003eThe duration of the operation, strategies for correcting the lower limb axis through modifying the position of patellar or soft tissue release, femoral cut angle differences, various types of implants, soft tissue release conditions, total blood loss, postoperative transfusion volume, and length of hospital stay were recorded by the same doctor. In addition, all the patients underwent preoperative and postoperative blood tests, from which the total blood loss was calculated. The primary TKA was conducted by doctors from the same group, and patient-reported outcome measures (PROMs), including hospital for special surgery knee score (HSS), knee society score (KSS), and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores, were collected. Moreover, the range of motion (ROM) was recorded during the follow-up, and the degree of pain was measured via the visual analog scale (VAS) score of postoperative pain at rest and during movement. An additional investigation was conducted to investigate the patients\u0026rsquo; satisfaction with the surgery, which was also evaluated by satisfaction scores (very satisfied: 9\u0026ndash;10, satisfied: 7\u0026ndash;8, moderate: 5\u0026ndash;6, not very satisfied: 3\u0026ndash;4, disappointed: 0\u0026ndash;2). Furthermore, complications, including intraoperative blood transfusion and infection, were recorded. Moreover, revision surgeries and implant survival rates were recorded.\u003c/p\u003e\n\u003ch3\u003eRadiographic assessment\u003c/h3\u003e\n\u003cp\u003eThe preoperative and postoperative weight-bearing long-leg X-rays and lateral views were collected and measured by the same doctor. The anteroposterior (AP) views were selected, and the hip-knee-angle (HKA) angles were measured. (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e) Other angles, such as the tibial slope angle (both medial and posterior), mechanical lateral distal femoral angle (mLDFA) and mechanical medial proximal tibial angle (mMPTA), were measured.(\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e) Lateral views were used to measure the posterior tibial slope (PTS). Furthermore, to evaluate loosening or infection of the prosthesis, the radiolucent line was measured, and pathological conditions were recorded. \u003cb\u003e(\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e,\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e)\u003c/p\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eData analysis\u003c/h2\u003e\u003cp\u003eAll the data were calculated and manipulated \u003cem\u003ewith GraphPad Prism 9.5.\u003c/em\u003e The data were checked visually for normality via histograms. Continuous variables such as the KSS and HSS scores were recorded as means with 95% confidence intervals (CIs), and their differences were analyzed by t tests. Categorical variables such as the visual analog scale (VAS) score were also recorded as the means with 95% confidence intervals (CIs); however, the results were compared via the Pearson test. P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was regarded as significant (\u003csup\u003e*\u003c/sup\u003e), and the number \u003csup\u003e*\u003c/sup\u003e represents the degree of significance.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\n \u003ch2\u003ePatient characteristics\u003c/h2\u003e\n \u003cp\u003eIn this retrospective study, patients who underwent TKA from September 2011 to September 2021 at PUMCH were selected, and 210 patients were selected (36 males and 174 females). According to the inclusion and exclusion criteria, 99 patients and 110 knees were included.\u003c/p\u003e\n \u003cp\u003eWe defined a valgus degree greater than 3\u0026deg; as a valgus deformity, categorizing 64 cases as neutral alignment (NA group) and 35 cases as undercorrection alignment. (UA group). Zero patients were found to be overcorrected. The flowchart of patient selection is shown in Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n \u003cp\u003eThe total average follow-up interval was 5.9 years, while the NA group had 3\u0026ndash;10 years of follow-up, with an average of 5.8 years, while the UA group had 3\u0026ndash;10 years of follow-up, with an average of 6.2 years, and no significant difference was shown (p\u0026thinsp;=\u0026thinsp;0.251, according to the t test; p\u0026thinsp;=\u0026thinsp;0.468, according to the Pearson test). The demographic characteristics and clinical classifications were not significantly different between the two groups. The detailed data are shown in Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eBaseline data for knees with neutral alignment and undercorrection alignment.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCharacteristics\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNeutral alignment group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eUndercorrection alignment group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAge (yrs.)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e64.95 (61.96\u0026ndash;67.95)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e64.23 (59.78\u0026ndash;68.68)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.7805\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eObesity (n) #\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2104\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e25.69 (24.66\u0026ndash;26.72)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e24.60 (23.56\u0026ndash;25.65)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.1727\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSex (male/female) #\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14/50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4/31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2015\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFollow-up interval(years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.756 (5.273\u0026ndash;6.239)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.225 (5.565\u0026ndash;6.886)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2506\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFollow-up groups#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4679\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 years follow-up\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5 years follow-up\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10 years follow-up\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOperation side(s) #\u003c/p\u003e\n \u003cp\u003eLeft\u003c/p\u003e\n \u003cp\u003eRight\u003c/p\u003e\n \u003cp\u003eDouble\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003cp\u003e41\u003c/p\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0.3445\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePre-operative osteoporosis #\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.3033\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eASA classification (n) #\u003c/p\u003e\n \u003cp\u003eGrade I\u003c/p\u003e\n \u003cp\u003eGrade II\u003c/p\u003e\n \u003cp\u003eGrade III\u003c/p\u003e\n \u003cp\u003eGrade IV-VI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0.1137\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eKL classification (n) #\u003c/p\u003e\n \u003cp\u003eGrade I-II\u003c/p\u003e\n \u003cp\u003eGrade III\u003c/p\u003e\n \u003cp\u003eGrade IV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e38\u003c/p\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0.8855\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eBMI, body mass index; ASA, American society of Aneshesiologists; K-L, Kellgren-Lawrence.\u003c/p\u003e\n \u003cp\u003eValues are mean (95% CI range) unless otherwise specified with #.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003eSurgical-related outcomes\u003c/h2\u003e\n \u003cp\u003eThe surgery-related outcomes are shown in Table \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e and include the angle of the femur cut, type of prosthesis (PS, CR or Constrained Condylar Knee (CCK) prosthesis), soft tissue release, length of hospital stay after the operation, duration of the operation, and total blood loss.\u003c/p\u003e\n \u003cp\u003eThere were no significant differences between the angles of the distal femur cut during the operation (p\u0026thinsp;=\u0026thinsp;0.643) and the angle of implant selection (p\u0026thinsp;=\u0026thinsp;0.265). Moreover, other surgical-related information, such as the length of hospitalization (p\u0026thinsp;=\u0026thinsp;0.734), duration of operation (p\u0026thinsp;=\u0026thinsp;0.231) and total blood loss (p\u0026thinsp;=\u0026thinsp;0.117), did not significantly differ between the two groups. The soft tissues most commonly released in the valgus knee during the TKA procedure were the posterolateral articular capsule and iliotibial tract band in this study. The lateral collateral ligament was also released in 9 patients in total (6 in the NA group and 3 in the UA group). There were no differences in the release frequencies of all three ligaments (p\u0026thinsp;=\u0026thinsp;0.908): the posterolateral articular capsule (p\u0026thinsp;=\u0026thinsp;0.451), iliotibial tract band (p\u0026thinsp;=\u0026thinsp;0.654), or lateral collateral ligament (p\u0026thinsp;=\u0026thinsp;0.844).\u0026nbsp;\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eSurgical related outcomes for knees with neutral alignment and undercorrection alignment.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSurgical outcomes\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNeutral alignment group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eUndercorrection alignment group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFemur cut angle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.422 (5.290\u0026ndash;5.554)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.371 (5.203\u0026ndash;5.540)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.6427\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTypes of prothesis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2650\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePS#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e64 (91.43%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33 (82.50%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCR#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (5.714%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6 (15.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCCK#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 (2.857%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1 (2.50%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRelease of soft tissue\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.9078\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePosterolateral articular capsule#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23 (32.85%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16 (40.00%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4513\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eIliotibial tract band#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10 (14.29%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7 (27.50%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.6537\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLateral collateral ligament#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6 (8.57%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (7.50%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.8437\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLength of stay after operation (days)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.828 (5.819\u0026ndash;7.838)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.229 (5.916\u0026ndash;8.541)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.7336\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDuration of operation (min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e108.0 (98.30-117.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e117.3 (101.4-133.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2922\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTotal blood loss (mL)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e806.2 (710.9-901.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e769.7 (608.7-930.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.1167\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003ePS, posterior stabilized; CR, cruciate retention; CCK, Constrained Condylar Knee prothesis.\u003c/p\u003e\n \u003cp\u003eValues are mean (95% CI range) unless otherwise specified with #.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n \u003ch2\u003eClinical outcomes\u003c/h2\u003e\n \u003cp\u003eThe clinical outcomes are presented in Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e. There were no statistically significant differences in postoperative outcome scores, including the KSS knee score (p\u0026thinsp;=\u0026thinsp;0.570), KSS function score (p\u0026thinsp;=\u0026thinsp;0.227), HSS score (p\u0026thinsp;=\u0026thinsp;0.467), WOMAC pain score (p\u0026thinsp;=\u0026thinsp;0.404), WOMAC function score (p\u0026thinsp;=\u0026thinsp;0.283), WOMAC stiffness score (p\u0026thinsp;=\u0026thinsp;0.592), or WOMAC total score (p\u0026thinsp;=\u0026thinsp;0.391), between the NA group and UA group. The ROM (p\u0026thinsp;=\u0026thinsp;0.939) also resembled that in both groups, with a mean of 129.0 degrees in the NA group and 128.7 degrees in the UA group. \u003cstrong\u003e(\u003c/strong\u003eTable \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e\u003cstrong\u003e)\u003c/strong\u003e There was no difference in the postoperative VAS pain score at rest (the average score of the NA group: the UA group 0.72: 1.2) (p\u0026thinsp;=\u0026thinsp;0.227) or during movement (1.4: 1.9) (p\u0026thinsp;=\u0026thinsp;0.266) between the UA group and the NA group. The patients were separated into different groups according to their satisfaction levels. The percentages of the very satisfied group in the NA group and the UA group were 54.7% and 42.9%, respectively, whereas the percentages of the satisfied group were 37.5% and 37.1%, moderate 3.1% and 8.6%, not very satisfied 4.7% and 5.7%, disappointing 0% and 5.7%, respectively. Generally, there was no difference in the satisfaction rate (p\u0026thinsp;=\u0026thinsp;0.226) between the two groups according to the Pearson test, and detailed satisfaction grouping data are recorded in Table \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e.\u0026nbsp;\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab3\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eClinical scores for knees with neutral alignment and undercorrection alignment.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eClinical scores\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNeutral alignment group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eUndercorrection alignment group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eKSS knee score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e86.80 (82.91\u0026ndash;90.69)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e84.71 (77.74\u0026ndash;91.68)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.5698\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eKSS function score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e89.92 (86.42\u0026ndash;93.42)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e85.43 (77.62\u0026ndash;93.24)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.2267\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHSS score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e87.73 (84.46\u0026ndash;91.01)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e85.23 (78.01\u0026ndash;92.45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.4671\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eWOMAC Pain score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.641 (1.156\u0026ndash;2.125)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.143 (0.7609\u0026ndash;3.525)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.4037\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eWOMAC function score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.266 (2.254\u0026ndash;4.277)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.457 (2.068\u0026ndash;6.846)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.2833\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eWOMAC stiffness score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.7500 (0.4756\u0026ndash;1.024)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.6286 (0.2743\u0026ndash;0.9829)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.5924\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eWOMAC total score\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5.656 (3.994\u0026ndash;7.319)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7.229 (3.267\u0026ndash;11.19)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.3912\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eROM (\u003csup\u003e\u0026deg;\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e129.0 (124.0-134.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e128.7 (122.4\u0026ndash;135.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.9386\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eKSS, knee society score; HSS, hospital for special surgery knee score; WOMAC, Western Ontario and McMaster University Osteoarthritis Index; ROM, range of motion.\u003c/p\u003e\n \u003cp\u003eValues are mean (95% CI range) unless otherwise specified with #.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab4\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eWOMAC Pain score and Satisfaction VAS scores for knees with neutral alignment and undercorrection alignment.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eClinical scores\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNeutral alignment group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eUndercorrection alignment group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePain at rest\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.7188 (0.4026\u0026ndash;1.035)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.171 (0.3321\u0026ndash;2.011)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2267\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePain at movement\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.375 (0.8646\u0026ndash;1.885)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.886 (1.066\u0026ndash;2.705)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2656\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSatisfaction\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2259\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eVery satisfied#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35 (54.69%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15 (42.86%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSatisfied#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e24 (37.50%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13 (37.14%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eModerate#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 (3.125%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (8.571%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNot very satisfied#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (4.688%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 (5.714%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDisappointed#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0 (0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 (5.714%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eWOMAC, Western Ontario and McMaster University Osteoarthritis Index; VAS, visual analog scale.\u003c/p\u003e\n \u003cp\u003eValues are mean (95% CI range) unless otherwise specified with #.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003ch2\u003eRadiographic results\u003c/h2\u003e\n \u003cp\u003eThe radiographic outcomes, which were mainly the preoperative and postoperative HKA, are presented in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e. There were also no clear differences in the preoperative HKA between the NA group and the undercorrection alignment group (means: 11.2\u003csup\u003e\u0026deg;\u003c/sup\u003e and 9.9\u003csup\u003e\u0026deg;,\u003c/sup\u003e respectively; p\u0026thinsp;=\u0026thinsp;0.131). The results of further grouping of mild and severe valgus knees also revealed no significant difference (p\u0026thinsp;=\u0026thinsp;0.211), with 6 patients in the mild valgus group and 58 in the severe valgus group in the NA group and 7 patients in the mild valgus group and 28 in the severe valgus group in the UA group. However, there was a significantly larger postoperative HKA in the UA group (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001, \u003csup\u003e****\u003c/sup\u003e), the mean of which was 6.3\u003csup\u003e\u0026deg;\u003c/sup\u003e compared with the 1.2\u003csup\u003e\u0026deg;\u003c/sup\u003e in the NA group.\u003c/p\u003e\n \u003cp\u003eMoreover, the medial and posterior tibial slope angles, mLDFA and mMPTA are also recorded in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e. No significant differences were found in the preoperative medial tibial slope angles, mLDFA or mMPTA (NA group: 2.1\u003csup\u003e\u0026deg;\u003c/sup\u003e (1.0\u0026ndash;3.2\u003csup\u003e\u0026deg;\u003c/sup\u003e); 83.0\u003csup\u003e\u0026deg;\u003c/sup\u003e (82.0\u0026ndash;84.0\u003csup\u003e\u0026deg;\u003c/sup\u003e); 88.0\u003csup\u003e\u0026deg;\u003c/sup\u003e (86.9\u0026ndash;89.1\u003csup\u003e\u0026deg;\u003c/sup\u003e); UA group: 1.1\u003csup\u003e\u0026deg;\u003c/sup\u003e (-0.3\u0026ndash;2.4\u003csup\u003e\u0026deg;\u003c/sup\u003e); 83.4\u003csup\u003e\u0026deg;\u003c/sup\u003e (81.3\u0026ndash;85.5\u003csup\u003e\u0026deg;\u003c/sup\u003e); 88.9\u003csup\u003e\u0026deg;\u003c/sup\u003e (87.6\u0026ndash;90.3\u003csup\u003e\u0026deg;\u003c/sup\u003e), and p\u0026thinsp;=\u0026thinsp;0.282; 0.705\u0026ndash;0.289, respectively). However, the postoperative mLDFA of the undercorrection group (86\u003csup\u003e\u0026deg;\u003c/sup\u003e.9\u003csup\u003e\u0026deg;\u003c/sup\u003e (85.9\u003csup\u003e\u0026deg;\u003c/sup\u003e-88.0\u003csup\u003e\u0026deg;\u003c/sup\u003e)) was much lower than that of the NA group (89.19\u003csup\u003e\u0026deg;\u003c/sup\u003e (88.8\u003csup\u003e\u0026deg;\u003c/sup\u003e-89.6\u003csup\u003e\u0026deg;\u003c/sup\u003e)) (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001, \u003csup\u003e****\u003c/sup\u003e), whereas the mMPTA was significantly greater (90.5\u003csup\u003e\u0026deg;\u003c/sup\u003e (89.8\u003csup\u003e\u0026deg;\u003c/sup\u003e-91.2\u003csup\u003e\u0026deg;\u003c/sup\u003e): 89.6\u003csup\u003e\u0026deg;\u003c/sup\u003e (89.2\u003csup\u003e\u0026deg;\u003c/sup\u003e-90.1\u003csup\u003e\u0026deg;\u003c/sup\u003e) for the undercorrection group and the NA group, respectively; p\u0026thinsp;=\u0026thinsp;0.034,\u003csup\u003e*\u003c/sup\u003e). Since the postoperative mMPTA of the two groups was approximately 90 degrees, the remaining valgum in the UA group was confirmed to be based mainly on undercorrection of the distal femur. In addition, the tibial plateau of the UA group tilted laterally (-0.5\u003csup\u003e\u0026deg;\u003c/sup\u003e (-1.2\u003csup\u003e\u0026deg;\u003c/sup\u003e-0.2\u003csup\u003e\u0026deg;\u003c/sup\u003e)) after surgery, whereas that of the NA group tilted slightly to the medial side (0.4\u003csup\u003e\u0026deg;\u003c/sup\u003e (-0.08\u003csup\u003e\u0026deg;\u003c/sup\u003e-0.8\u003csup\u003e\u0026deg;\u003c/sup\u003e)). This significant difference (p\u0026thinsp;=\u0026thinsp;0.038) might also contribute to the remaining deformity. Other postoperative angles were not significantly different. \u003cstrong\u003e(\u003c/strong\u003eTable\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e\u003cstrong\u003e)\u003c/strong\u003e Finally, no pathological radiolucent line was recorded in any of the patients, indicating that no cases of implant loosening or infection occurred.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n \u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n \u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n \u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n \u003ctable id=\"Tab5\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eRadiographic outcomes for knees with neutral alignment and undercorrection alignment.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eRadiographic outcomes\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNeutral alignment group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eUndercorrection alignment group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHKA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePre-operative HKA (\u003csup\u003e\u0026deg;\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11.22 (10.26\u0026ndash;12.18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.914 (8.368\u0026ndash;11.46)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.1314\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGroups:\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2114\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMild valgus knee\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSevere valgus knee\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePost-operative HKA (\u003csup\u003e\u0026deg;\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.219 (0.9081\u0026ndash;1.529)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.286 (5.711\u0026ndash;6.860)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMedial tibial slope angle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePre-operative medial tibial slope angle (\u003csup\u003e\u0026deg;\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.059 (0.9564\u0026ndash;3.161)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.076 (-0.2563-2.409)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2822\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePost-operative medial tibial slope angle (\u003csup\u003e\u0026deg;\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.3529 (-0.08119-0.7871)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e-0.4771 (-1.196-0.2412)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.0381\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePosterior lateral tibial slope angle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePre-operative posterior tibial slope angle (\u003csup\u003e\u0026deg;\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.032 (6.740\u0026ndash;9.324)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6.261 (4.298\u0026ndash;8.225)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.1169\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePost-operative lateral posterior tibial slope angle (\u003csup\u003e\u0026deg;\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.034 (3.268\u0026ndash;4.801)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.263 (3.107\u0026ndash;5.418)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.7487\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003emLDFA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePre-operative mLDFA (\u003csup\u003e\u0026deg;\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e83.01 (82.03-84.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e83.39 (81.33\u0026ndash;85.46)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.7053\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePost-operative mLDFA (\u003csup\u003e\u0026deg;\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e89.19 (88.80-89.58)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e86.90 (85.85\u0026ndash;87.95)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003emMPTA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePre-operative mMPTA (\u003csup\u003e\u0026deg;\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e87.96 (86.86\u0026ndash;89.06)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e88.92 (87.59\u0026ndash;90.26)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2886\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePost-operative mMPTA (\u003csup\u003e\u0026deg;\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e89.63 (89.20-90.06)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e90.48 (89.76\u0026ndash;91.20)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.0335\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePathological radiolucent line#\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eHKA, hip-knee-angle; mLDFA, mechanical lateral distal femoral angle; mMPTA, mechanical medial proximal tibial angle.\u003c/p\u003e\n \u003cp\u003eValues are mean (95% CI range) unless otherwise specified with #. Positive values refer to valgus angles.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\n \u003ch2\u003eComplications\u003c/h2\u003e\n \u003cp\u003eAs shown in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e, generally, no significant differences were detected between the two groups (p\u0026thinsp;=\u0026thinsp;0.555). Moreover, the most common complication after TKA is deep venous thrombosis in the lower extremities. Thrombosis occurs in approximately 2.0% of patients who undergo TKA even with antithrombosis strategies.(\u003cspan class=\"CitationRef\"\u003e23\u003c/span\u003e) The percentages of deep venous thrombosis in both groups were 3.1 and 2.9%, respectively, which were not significantly different (p\u0026thinsp;=\u0026thinsp;0.915). Peroneal nerve injury is also considered to be related to the release of lateral ligaments during TKA.(\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e) However, no patients experienced such injuries. None of the patients in either group underwent revision surgery after their primary TKA, representing 100% survival of the implants. However, there were more types of complications in the NA group.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n \u003cdiv class=\"colspec\" align=\"char\"\u003e\u0026nbsp;\u003c/div\u003e\n \u003cdiv class=\"colspec\" align=\"char\"\u003e\u0026nbsp;\u003c/div\u003e\n \u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n \u003ctable id=\"Tab6\" border=\"1\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003ePost-operative complications and survivorship for knees with neutral alignment and undercorrection alignment.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eComplications#\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eNeutral alignment group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eUndercorrection alignment group\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDeep venous thrombosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.9150\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBlood intravenous infusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.9407\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOsteoporosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2493\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLung nodule\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.2907\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eProthesis infection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4573\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePeriprosthetic fractures\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4573\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePatella Baja\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4573\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLower lobe pulmonary bulla\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4573\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRenal cyst\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4573\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCystic density lesion in the adnexal region\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4573\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHyperuricemia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4573\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCoronary artery plaque formation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4573\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eChronic otitis media\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4573\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHyperlipidemia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4573\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eChronic superficial gastritis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.4573\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDiabetes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.1741\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUrinary tract infection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.1741\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRosacea\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.1741\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThyroid nodule\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.1741\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eImplant failure\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e/\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eValues are mean (95% CI range) unless otherwise specified with #.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eSince neutral mechanical alignment has long been considered the best treatment and remains the trending method, other methods for TKA, such as anatomical or kinematic alignment, which retains the varum, have also been reported to provide good results.(\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e) However, the results of the remaining volume after TKA have rarely been reported, which makes the current research necessary to obtain a complete review of TKA prognosis.\u003c/p\u003e\u003cp\u003eThe current research focused mainly on the prognosis between TKA with a neutral alignment and the valgum remaining strategy. Primarily, the resemblance of the recovery time in hospitals between the two strategies showed no clear difference. The detailed data revealed that there were no significant changes in the PROMs between the NA group and the UA group, indicating that the functional recovery of the two groups was associated with comparable outcomes. The lack of significant variation in the ROM results also demonstrated a similar functional prognosis.\u003c/p\u003e\u003cp\u003eRadiographic results revealed that the preoperative angles of the lower limb axis did not vary significantly, whereas the postoperative mLDFA deviated more from the neutral alignment (90\u0026deg;) in the UA group, indicating that the undercorrection of the valgus knee was usually caused by the remaining deformity at the femur site. It has long been recognized that varus deformities of the tibia can induce implant failure. (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e) However, in 2023, Luyckx et al reported that when the femoral component was placed in \u0026gt;\u0026thinsp;3\u0026deg; of valgus (mLDFA\u0026thinsp;\u0026lt;\u0026thinsp;87\u0026deg;), the survival of the implant significantly (p\u0026thinsp;=\u0026thinsp;0.003) decreased over 12.9 years of follow-up, whereas the alignment of the tibia had a minor effect (p\u0026thinsp;=\u0026thinsp;0.855).(\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e) However, in our research, no survival difference was recorded due to the differences in mLDFA. The contradictions in survival might be attributed to the shorter interval of follow-up and different surgical strategies. Moreover, in the NA group, the operation significantly decreased the PTS (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001, \u003csup\u003e****\u003c/sup\u003e), whereas in the UA group, it did not (p\u0026thinsp;=\u0026thinsp;0.065). These findings revealed that, in the undercorrection group, osteotomy was not sufficient to change the original deformity, and similar clinical outcomes were achieved. PTS has been reported to be crucial for the stability of knee joints, the reduction of which could decrease the possibility of implant failure in anterior cruciate ligament reconstruction operations.(\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e) However, considering the similar results of the PROMs of the patients in this study, the patients seemed to be accustomed to the deformity, which mightpotentially lead to less loss of bone mass in future surgeries. In addition, the results were consistent with those of previous studies; more postoperative radiographic angles were compared by Lee et al.(\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e), who reported no significant differences between the conventional method and the valgum-remaining strategy.\u003c/p\u003e\u003cp\u003ePatient satisfaction has been regarded as crucial for defining whether TKA is successful. Various factors are considered to affect the satisfaction of patients, including the type of prosthesis,(\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e) PROMs,(\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e) occurrence of complications(\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e) and postoperative rehabilitation process.(\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e) In this study, there was no difference in the factors above, resulting in similar levels of satisfaction between the two groups. However, an F test was further conducted to compare the variances between the two groups and revealed significant differences (p\u0026thinsp;=\u0026thinsp;0.0011, \u003csup\u003e**\u003c/sup\u003e), revealing much greater standard variance in the UA group (2.390) than in the NA group (1.489), which might reveal that a strategy aimed at neutral alignment could lead to more stable outcomes.\u003c/p\u003e\u003cp\u003eFinally, gait alternations could also be included in the prognosis of TKA since it was reported that gait was associated with feelings of pain and the type of prosthesis. Generally, TKA relieves pain and improves gait performance.(\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e) Recently, Fukui et al(\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e) examined gait alternations with a Walkway analyzer, a sheet-type gait analyzer, and reported that after unilateral TKA, the time indices, stance phase, and double-limb support phase time, which were shorter on the affected side, whereas the swing phase, which was longer on the affected side, normalized after the operation. Moreover, the different outcomes of gait after TKA due to different types of prostheses and the combination of ankle arthritis have also been reported, suggesting that different strategies of TKA might result in various gaits.(\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e) Nevertheless, whether the remaining valgum affects gait compared with the neutral alignment has not been fully researched, and more studies could be performed to compare the two strategies of TKA.\u003c/p\u003e\u003cp\u003eThe traditional mechanical alignment remains the gold standard for reducing damage to the implant by ensuring equal distribution of loads between the medial and lateral compartments of the knee and thus alleviating the shear forces between the implants and bone.(\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e) Moreover, in contrast to the method of remaining varum, which is based mainly on kinematic or anatomical alignment, the retention of valgum is not based on the constituted anatomic varum of the tibio-femoral alignment; the purpose of retaining the valgum could be attributed to the severity of the preoperative valgum,(\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e) and other reasons remain to be researched. However, according to the follow-up results, the prognosis did not differ clearly between the anatomic alignment technique and the valgum-remaining technique. The discomfort of patients after TKA is considered to be caused mainly by implant loosening or failure. Neutral alignment has been reported to reduce the asymmetric bearing wear of implants, which can potentially increase the survival rate of the prosthesis.(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e) However, more detailed research revealed that the failure rate in knees with varus alignment was significantly greater than that in knees with neutral alignment (p\u0026thinsp;=\u0026thinsp;0.02), whereas no significant difference was detected in the survival rates of patients with valgus malalignment and neutral alignment.(\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e) No revision surgeries were performed after the last TKA in either group in this research; thus, a longer follow-up time might be necessary. Furthermore, the relationship between the level of undercorrection and the degree of implant failure remains unclear. More studies are needed to evaluate the survival of implants in patients with different degrees of valgum remaining. Additionally, since only a few patients with severe valgum had HKA values greater than 20\u0026deg;, both the NA group and UA group had severe valgum values. The prognosis of TKA patients has yet to be fully reported, and it is difficult to propose a proper treatment strategy. In addition, soft tissue release is the most commonly used method to correct the lower limb axis and create proper gaps between bones. For the correction of valgus knees, the release of the lateral ligaments, including the iliotibial tract band or the lateral collateral ligament, and the posterolateral articular capsule and constriction of the medial ligament, such as the medial collateral ligament, have all been reported to be efficient.(\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e, \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e) Nevertheless, there are alternations in the previous joint line, which patients are likely accustomed to due to prolonged reformation of soft tissue.(\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e) A multicenter study conducted by Vigdorchik et al.(\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e) also revealed that additional release of soft tissue would also lead to a worse prognosis. However, in this study, no significant difference in the release of lateral soft tissues was recorded, which might be the potential reason for the similar outcomes.\u003c/p\u003e\u003cp\u003eFurther studies can be conducted to create better designs for TKA. Currently, the Coronal Plane Alignment of the Knee (CPAK) classification is widely used to generate more detailed categories of knee deformations. The conventional definition for the valgus knee is related to the HKA when HKA\u0026thinsp;\u0026gt;\u0026thinsp;3\u0026deg; is considered the knee valgum. However, the CPAK standard separates the valgus knee into 3 detailed groups considering the different joint line obliquity (JLO) values (mMPTA\u0026thinsp;+\u0026thinsp;mLDFA). When the mMPTA\u0026thinsp;+\u0026thinsp;mLDFA is greater than 180\u0026deg;, it is called the apex proximal deformity, whereas when the mMPTA\u0026thinsp;+\u0026thinsp;mLDFA is less than 180\u0026deg;, it is called the apex distal deformity. Thus, the knee valgum is categorized into 3 groups, namely, CPAK III (valgum combining apex distal), VI (valgum with neutral JLO) and IX (valgum combining apex proximal).(\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e) For different CPAK types of valgus, different TKA strategies, including mechanical alignment and kinetic alignment, can yield various outcomes, and the optimal choices for each type of valgum vary, similar to the differences in survivorship mentioned previously.(\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e) Even though, generally, the mMPTA and mLDFA were elevated significantly after surgery (NA group: p\u003csub\u003emMPTA\u003c/sub\u003e=0.0053, \u003csup\u003e**\u003c/sup\u003e; p\u003csub\u003emLDFA\u003c/sub\u003e\u0026lt;0.0001, \u003csup\u003e****\u003c/sup\u003e; UA group: p\u003csub\u003emMPTA\u003c/sub\u003e= 0.0392, \u003csup\u003e*\u003c/sup\u003e; p\u003csub\u003emLDFA\u003c/sub\u003e= 0.0028, \u003csup\u003e**\u003c/sup\u003e), the majorly altered angles in different patients varied. Furthermore, we assumed that for the undercorrection alignment strategy, there should be different optimal valgus angles as well as the mMPTA and mLDFA for different patients; however, no specific research has been conducted to identify exact strategies. Finally, since the robotic operation strategy is now prevalent and still in need of modification to achieve the best result, as the previous standard was to be as accurate as possible to achieve mechanical alignment, which was found to be not suitable for all patients,(\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e) this research might contribute to the development of more flexible criteria for judgment of the section angle during robotic operation.(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)\u003c/p\u003e\u003cp\u003eNevertheless, there are still many limitations that need improvement in this research. More patients can be included in our studies, and longer-term follow-up is needed to assess outcomes over a longer period. Moreover, the number of included cases was limited, and complex cases were not included. Randomized controlled trials (RCTs) are needed in the future. Finally, no further investigations of the mechanisms of the influence of valgus deformity on patients were carried out in this study, which is also needed in the future.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study revealed no significant differences in postoperative outcomes between TKA patients with conventional mechanical alignment and those with slight valgus retention. This finding suggests that retaining slight valgus with an average angle of 6.3\u0026deg; may not compromise the success of TKA and could offer an alternative standard for surgical planning.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003ch2\u003eEthics statement\u003c/h2\u003e\u003cp\u003e This study was reviewed and approved by Peking Union Medical College Hospital and the Peking Union Medical College Hospital Ethics Committee. (IRB: I-24PJ2200) All participants provided informed consent for treatment. The patients provided written informed consent to participate in this study. Written informed consent was obtained from the individuals for the publication of any potentially identifiable images or data included in this article.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003ch2\u003eConsent to Publish\u003c/h2\u003e\u003cp\u003eConsent to publication was obtained from the participants.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003ch2\u003eClinical trial number\u003c/h2\u003e\u003cp\u003eNot applicable.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003ch2\u003eConflict of interest\u003c/h2\u003e\u003cp\u003eAll the authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or nonfinancial interest in the subject matter or materials discussed in this manuscript.\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e\u003cp\u003eNot applicable.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eThis work was designed by Xisheng Weng and Bin Feng. The procedures were performed by Xisheng Weng and Bin Feng. The data were collected by Runze Zhou and Hanyang Sun. The data were analyzed by Runze Zhou, Yixin Bian and Zhanqi Wei. This manuscript was written by Runze Zhou and Zhanqi Wei. All the authors approved the final version.\u003c/p\u003e\u003ch2\u003eData availability statement\u003c/h2\u003e\u003cp\u003eThe original contributions presented in the study are included in the article. Further inquiries can be directed to the corresponding author.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMartel-Pelletier J, Barr AJ, Cicuttini FM, Conaghan PG, Cooper C, Goldring MB et al (2016) Osteoarthr Nat Rev Dis Primers 2:16072\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGlyn-Jones S, Palmer AJR, Agricola R, Price AJ, Vincent TL, Weinans H et al (2015) Osteoarthr Lancet 386(9991):376\u0026ndash;387\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFavorito PJ, Mihalko WM, Krackow KA (2002) Total knee arthroplasty in the valgus knee. J Am Acad Orthop Surg 10(1):16\u0026ndash;24\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRossi R, Rosso F, Cottino U, Dettoni F, Bonasia DE, Bruzzone M (2014) Total knee arthroplasty in the valgus knee. 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J Bone Joint Surg Am 91(10):2461\u0026ndash;2468\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEspandar R, Mortazavi SM-J, Baghdadi T (2010) Angular deformities of the lower limb in children. Asian J Sports Med 1(1):46\u0026ndash;53\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChang CB, Shetty GM, Lee JS, Kim YC, Kwon JH, Nha KW (2017) A Combined Closing Wedge Distal Femoral Osteotomy and Medial Reefing Procedure for Recurrent Patellar Dislocation with Genu Valgum. Yonsei Med J 58(4):878\u0026ndash;883\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGulati A, Chau R, Pandit HG, Gray H, Price AJ, Dodd CAF et al (2009) The incidence of physiological radiolucency following Oxford unicompartmental knee replacement and its relationship to outcome. 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Knee Surg Sports Traumatol Arthrosc 31(10):4171\u0026ndash;4178\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOnishi S, Kim Y, Nakayama H, Mansour AA 3rd, Lowe WR, Ollivier M (2024) Infratubercle Anterior Closing Wedge Osteotomy Corrects Sagittal Alignment without Affecting Coronal Alignment or Patellar Height. J Clin Med. ;13(16)\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDorr LD, Ochsner JL, Gronley J, Perry J (1988) Functional comparison of posterior cruciate-retained versus cruciate-sacrificed total knee arthroplasty. Clin Orthop Relat Res. (236):36\u0026ndash;43\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBlackburn AZ, Feder O, Amakiri I, Melnic CM, Huddleston JI, Malchau H et al (2024) One-Year Postoperative Patient-Reported Outcome Measures Are Associated With Three-Year to Five-Year Postoperative Satisfaction in Total Knee Arthroplasty. J Arthroplasty 39(3):683\u0026ndash;688\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJiao S, Feng Z, Dai T, Huang J, Liu R, Meng Q (2024) High-Intensity Progressive Rehabilitation Versus Routine Rehabilitation After Total Knee Arthroplasty: A Randomized Controlled Trial. J Arthroplasty. ;39(3)\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKroll MA, Otis JC, Sculco TP, Lee AC, Paget SA, Bruckenstein R et al (1989) The relationship of stride characteristics to pain before and after total knee arthroplasty. Clin Orthop Relat Res. (239):191\u0026ndash;195\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFukui J, Matsui Y, Mizuno T, Watanabe T, Takemura M, Ishizuka S et al (2024) Comparison of gait analysis before and after unilateral total knee arthroplasty for knee osteoarthritis. J Orthop Surg Res 19(1):506\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKikuchi N, Kanamori A, Kadone H, Okuno K, Hyodo K, Yamazaki M (2024) Varus knee osteoarthritis with ankle osteoarthritis demonstrates greater hindfoot inversion and larger ankle inversion loading during gait following total knee arthroplasty compared to varus knee osteoarthritis alone. Knee Surg Sports Traumatol Arthrosc 32(9):2309\u0026ndash;2317\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAunan E, R\u0026ouml;hrl SM (2018) No detrimental effect of ligament balancing on functional outcome after total knee arthroplasty: a prospective cohort study on 129 mechanically aligned knees with 3 years' follow-up. Acta Orthop 89(5):548\u0026ndash;554\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTian F, Zang XH, Sun YS (2018) Impact of knee varus and valgus deformity on alignment in lower extremities after total knee arthroplasty (TKA). Eur Rev Med Pharmacol Sci 22(1 Suppl):83\u0026ndash;89\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu H-X, Shang P, Ying X-Z, Zhang Y (2016) Shorter survival rate in varus-aligned knees after total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 24(8):2663\u0026ndash;2671\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWhiteside LA (1993) Correction of ligament and bone defects in total arthroplasty of the severely valgus knee. Clin Orthop Relat Res. (288):234\u0026ndash;245\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKrackow KA, Jones MM, Teeny SM, Hungerford DS Primary total knee arthroplasty in patients with fixed valgus deformity. Clin Orthop Relat Res. 1991(273).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVictor JMK, Bassens D, Bellemans J, G\u0026uuml;rsu S, Dhollander AAM, Verdonk PCM (2014) Constitutional varus does not affect joint line orientation in the coronal plane. Clin Orthop Relat Res. ;472(1)\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVigdorchik JM, Wakelin EA, Koenig JA, Ponder CE, Plaskos C, DeClaire JH et al (2022) Impact of Component Alignment and Soft Tissue Release on 2-Year Outcomes in Total Knee Arthroplasty. J Arthroplasty. ;37(10)\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDrexler M, Abolghasemian M, Barbuto R, Naini MS, Voshmeh N, Rutenberg TF et al (2017) Patient's Height and Hip Medial Offset Are the Main Determinants of the Valgus Cut Angle During Total Knee Arthroplasty. J Arthroplasty 32(5):1496\u0026ndash;1501\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Total Knee Arthroplasty, Valgus Deformity, Alignment, Postoperative Prognosis, Patient Satisfaction","lastPublishedDoi":"10.21203/rs.3.rs-7329372/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7329372/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eValgus knees are common deformities induced by osteoarthritis (OA), which is usually characterized by a hip–knee angle (HKA)\u0026gt;3° valgus or a femoral-tibial angle (FTA)\u0026lt;170°. Total knee arthroplasty (TKA) is a pivotal treatment for valgus knee deformity in end-stage knee OA; however, the optimal alignment strategy remains a subject of debate. Traditionally, TKA aims for a neutral mechanical alignment (-3°\u0026lt; HKA \u0026lt;3°); however, the impact of retaining slight valgus (HKA\u0026gt;3°) alignment post-TKA has not been extensively studied.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003eThis retrospective study included patients with knee valgus who underwent TKA from September 2011 to September 2021. Patients were divided into two groups on the basis of postoperative HKA: neutral alignment (NA group) (-3°\u0026lt;HKA\u0026lt;3°) and undercorrection alignment (UA group) (HKA\u0026gt;3°). The clinical outcomes were assessed by the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), KSS, Hospital for Special Surgery (HSS) knee score, range of motion (ROM) and visual analog scale (VAS). Patient satisfaction and radiographic outcomes were also compared between the two groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e A follow-up of 3–10 years was conducted on 99 patients, with an average age of 5.9 years, with no significant demographic differences between the NA and UA groups. Surgical outcomes, including hospital stay, operation duration, and total blood loss, were not obviously different. Pain scores were also measured by the WOMAC and were not significantly different between the two groups, nor were visual analog scale (VAS) scores or pain during movement. The clinical scores (KSS, HSS, and WOMAC function, stiffness, and total scores) and range of motion (ROM) were also comparable, as was patient satisfaction. The radiographic results demonstrated that the preoperative HKA was similar, but the postoperative HKA was significantly greater (p\u0026lt;0.0001, ****) in the UA group due to the study design. Other radiographic results, including the medial and posterior tibial slopes (PTS), mechanical lateral distal femoral angle (mLDFA) and mechanical medial proximal tibial angle (mMPTA), showed no significant differences preoperatively, but the postoperative mLDFA was significantly lower in the UA group (p\u0026lt;0.0001,\u003csup\u003e ****\u003c/sup\u003e). The incidence of complications and survival did not markedly differ between the groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e This study revealed no significant differences in postoperative outcomes between TKA patients with neutral alignment and those with slight valgus retention. This suggests that retaining slight valgus of an average of 6.3° may not compromise the success of TKA and could offer an alternative standard for surgical planning.\u003c/p\u003e","manuscriptTitle":"Valgus Considered: Redefining Total Knee Arthroplasty Alignment for Optimal Patient Outcomes","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-02 06:44:09","doi":"10.21203/rs.3.rs-7329372/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"bd2cb921-8ecd-4f61-8d35-e21c37ac81b9","owner":[],"postedDate":"September 2nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-10-27T14:38:18+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-02 06:44:09","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7329372","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7329372","identity":"rs-7329372","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}