From Empirical to Analytical: Synergizing Robotic Assistance with Customized Implants for Superior TKA Outcomes

From Empirical to Analytical: Synergizing Robotic Assistance with Customized Implants for Superior TKA 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 From Empirical to Analytical: Synergizing Robotic Assistance with Customized Implants for Superior TKA Outcomes Hanlong Zheng, Zhaolun Wang, Ji Zhang, Kaiding Wu, Jiajun Zheng, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9065050/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 17 You are reading this latest preprint version Abstract Background Despite advancements in robotic-assisted total knee arthroplasty (TKA), improvements in patient satisfaction remain limited. This study aimed to compare outcomes and satisfaction among three TKA approaches: robotic-assisted TKA with patient-specific implants, robotic-assisted TKA with off-the-shelf implants, and manual TKA with off-the-shelf implants. Methods A retrospective cohort study was conducted on 140 knees who underwent TKA between December 2022 and December 2024. Patients were categorized into three groups: RA-C group (n = 43), which underwent robotic-assisted TKA with customized implants; RA-O group (n = 45), which received robotic-assisted TKA using Mako system with off-the-shelf implants; and Manual group (n = 52), which underwent conventional manual TKA using AK A3 GT implants. Customized implants in RA-C group were individually designed based on preoperative CT scans to optimize bony coverage and sagittal curvature, and featured separate medial and lateral tibial inserts. Outcomes included alignment, Knee Injury and Osteoarthritis Outcome Score (KOOS), Forgotten Joint Score (FJS), and a 5-level patient satisfaction scale. Results No significant differences were found in baseline demographics. In terms of post-operative outcomes, The RA-C group demonstrated significantly higher patient satisfaction than other groups (86.0% very satisfied, 11.6% satisfied and 2.3% neutral, p = 0.002). The RA-C group also presented a higher FJS-12 score (78.0 ± 14.2) compared to the Manual group (67.4 ± 20.2, p = 0.012). Conclusion Synergizing robotics with customized implants showed superior satisfaction and functional outcomes compared to robotic-assisted TKA with off-the-shelf implants and manual TKA. Individualized implant design, rather than robotics alone, may be more critical in optimizing TKA outcomes. Robotic-assisted TKA Patient-specific implants Customized Surface geometry Gap balancing Patient satisfaction Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Soft-tissue imbalance remains one of the leading causes of postoperative dissatisfaction in total knee arthroplasty (TKA) [ 1 ]. With the development of robotic technology, the paradigms of TKA alignment have been changing from mechanical alignment to functional /kinematic alignment, potentially reducing soft-tissue releases, achieving better gap balance while respecting alignment boundary[ 2 ]. However, whether robotics alone can consistently improve patient satisfaction and functional outcomes remains controversial [ 3 – 5 ]. A fundamental challenge lies in the discrepancy between standardized implants and individual anatomy: while anatomical morphology and soft-tissue elasticity exhibit significant variability among individuals [ 6 – 11 ], prosthetic geometries are typically standardized. Consequently, this mismatch generates kinematic conflicts—defined as the disharmony between the motion dictated by the implant's geometry and the natural kinematics guided by the patient's soft-tissue envelope—which may contribute to mid-flexion instability, stiffness, and persistent pain [ 9 , 12 ]. While patient-specific TKA implants have emerged to address these challenges[ 13 , 14 ], current applications often fall short of functional restoration [ 15 – 19 ]. Critically, most systems achieve only 'implant individualization' in terms of morphological fit (bony coverage) while retaining standardized articular curvatures, thus failing to address the underlying kinematic mismatch. Moreover, reliance on conventional instruments or static patient-specific guides (PSI) restricts restricts the surgery to a purely mechanical process, denying surgeons the ability to perform intraoperative quantitative analysis or apply mathematical decision-making, rendering personalized, dynamic optimization of the joint gap impossible [ 20 , 21 ]. Our team initially synergized robotics and customized implants in TKA procedure, in an 'Analytical' approach. Utilizing a CT-based system integrated with quantitative gap-force sensors, this approach employs a novel modular implant system designed for independent medial-lateral optimization. On the tibial side, surgeons can independently select and combine medial and lateral inserts—varying in thickness, congruency, and posterior slope—based on real-time intraoperative sensor data. On the femoral side, distal condylar and posterior condylar thickness could also be modifyed. By synergizing this analytical workflow with the implant’s comprehensive modularity, surgeons can achieve a multi-factorial optimization of the joint—balancing gap tension, surface geometry, and rotational kinematics simultaneously. However, comparative evidence supporting the clinical superiority of this technique remains limited. Consequently, the objective of this study was to evaluate whether this shift from empirical to analytical surgery translates to clinical benefit. We compared patient satisfaction, functional scores, and radiological outcomes across three distinct approaches: Analytical TKA with patient-specific implants (RA-C), robotic-assisted TKA with off-the-shelf implants (RA-O), and conventional manual TKA with off-the-shelf implants (Manual). We hypothesized that the Analytical TKA approach, by synergizing intraoperative quantitative balancing with geometric customization, would effectively mitigate kinematic conflicts and yield superior patient satisfaction compared to standard off-the-shelf techniques. Patients and Methods Patient Selection This retrospective-cohort study was approved by the institutional review board (IRB) of our institute. Patients who underwent TKA between Dec 2022 and Dec 2024 were enrolled and divided into 3 sub-groups: Robotic-assisted TKA with customized implants (RA-C), Robotic-assisted TKA with off-the-shelf implants (RA-O), Manual TKA with off-the-shelf implants (Manual). Inclusion Criteria： 1.Patients aged 50 to 80 years. 2.Varus or flexion deformity < 25°, and valgus deformity < 20°. 3.For subgroup allocation: RA-C Group: Robotic-assisted TKA using AK (AK Medical, Beijing, China) customized cruciate-retaining (CR)implants. RA-O Group: Robotic-assisted TKA with the MAKO system and cruciate-retaining (CR) implants. Manual Group: Manual TKA with an A3GT (AK Medical, Beijing, China) CR prosthesis. Exclusion Criteria： 1.Knee instability or posterior cruciate ligament (PCL) deficiency contraindicating a cruciate-retaining (CR) TKA procedure. 2.Incomplete data. 3.Inability or unwillingness to comply with follow-up assessments. Implant Customization Patients in RA-C group underwent hip-knee-ankle CT scans twelve weeks before surgery, both for robotic planning and implant customization. Utilizing CAD software for 3-D modeling, surface geometry designs were based on the of their off-the-shelf product (A3GT, AK Medical, Beijing, China), modifying the anteroposterior (AP) and mediolateral (ML) dimensions as well as anterior flange, to acquire best bony coverage. If a patient presented with knee laxity, hyperextension, we prepare implants and trial components with a 1.5 mm thickening of the distal femur; In severe flexion deformity, 2mm thickening posterior condyle would be additionally perpared, to well-adapt the flexion-extension mismatch. The curvature transition areas were smoothed, and the surgeon had alternative options for femoral condyles based on intraoperative balancing. The customization of tibial tray was achieved by optimizing best coverage, with separately designed medial and lateral tibial inserts. Surgical Procedures RA-C group All procedures were performed using TiRobot Recon system, based on hip-knee-ankle CT scans. A mid-patellar approach was used, osteophytes were initially removed, and the anterior cruciate ligament (ACL) was excised. After registration, the maximum medial and lateral gaps during knee flexion and extension were captured, and the surgical plan was adjusted using a "titration" of sequential bone-cutting technique[22] (Fig.2). The robot’s starting alignment was mechanical, and boundary of alignment was 4 degrees on the tibia and 5 degrees in total. Bone-cut of distal femur, posterior condyles, posterior chamfer and tibia were initially performed, medial and lateral meniscus were excised, leaving the anterior femoral cortex and anterior chamfer untouched, allowing for further possible adjustments. A "pre-cutting" femoral trial component was inserted, sharing the same surface geometry as the distal and posterior part of A3GT condyle, while 2 mm thinner in general, without anterior flange or chamfer. To quantify gap-forcing balance, Solver (Tinavi Beijing, China) were employed [22, 9], calculating absolute gaps at certain force and elastic modulus of collateral ligaments (Fig.3). According to the matrix of the Solver, if necessary, surgeons will do a secondary adjustment and finish the whole bone-cut of the femur. Trials were then implanted to assess medial/lateral gaps and tibiofemoral kinematics. Anterior drawer test (ADT) were also captured to evaluate anteroposterior translation. In RA-C group, our protocol for implant section was shown in Figure 4. Optimized femorl condyles were provided for extension-flexion eqality. Different thicknesses (8–14 mm), posterior slopes (3° or 6°), and deep-dish constrained liners could be selected to optimize balance, kinematics and stability. RA-O group All surgeries in RA-O group were performed using Mako system. Surgical approach, robotic manipulation and alignment boundary were similar. To minimize the confounding factors of different robots and gap-balancing techniques, Solver was also adopted in this group. Triathlon CR implants were used, with the 9mm, 11mm and 13mm thickness of tibial inserts eligible. Manual group All patients underwent manual TKA used A3GT prosthesis (AK medical, Beijing China). This multi-radius designed implant was the prototype of customized implants in our study. Surgical approach was identical to other groups. Femoral bone-cut employed intramedullary guidance, while tibial bone-cut used extramedullary guidance, both utilizing measured resection techniques starting with mechanical alignment, although a maximum of 5 degrees residual was permitted. Gap balancing was assessed using spacer blocks. Inserts with 8mm, 10mm and 12mm were eligible, all of which were designed 3 degrees’ slope. All operations in our study were performed by two experienced surgeons who shared the same surgical philosophy and alignment preference. The posterior cruciate ligament (PCL) was preserved in all cases, and no patellar resurfacing was performed. All implants were cemented. Data Collection Patient demographic data were collected, including gender, age, height, weight, BMI, and preoperative alignment. Postoperative follow-up included patient satisfaction (categorized as very dissatisfied, dissatisfied, neutral, satisfied, or very satisfied), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Forgotten Joint Score (FJS). Post-operative radiographic analysis included the overall hip-knee-ankle (HKA) alignment and medial proximal tibial angle (MPTA). Statistical Analysis All data were analyzed using SPSS version 22.0. Analysis of variance (ANOVA) was used to compare continuous variables among the three groups, post hoc pairwise comparisons were performed using the Least Significant Difference (LSD) test. Categorical variables were analyzed using the chi-square test. Satisfaction grades were compared using the Kruskal-Wallis H test, and post-hoc pairwise comparisons were performed using Mann-Whitney U test with Bonferroni correction (where the p-value was multiplied by 3 to account for the three pairwise tests). Statistical significance was determined at the p < 0.05 level. Results A total of 140 patients (150 knees) met inclusion criteria, and 10 patients were excluded.The final enrollment (Figure 5) included 43 knees in RA-O group, 45 knees in RA-C group and 52 knees in Manual group. Patient demographics were shown in Table 1. Baseline characteristics of the three groups were compared. No statistically significant differences were found in terms of gender, operative side, age, height, weight, body mass index (BMI), preoperative hip-knee-ankle angle (HKA), or follow-up duration. Table 1. Patient demographics Variables RA-C Group (N=43) RA-O Group (N=45) Manual Group (N=52) Total (N=140) P value Gender (Male/Female) 15 (34.9) / 28 (65.1) 12 (26.7) / 33 (73.3) 18 (34.6) / 34 (65.4) 45 (32.1) / 95 (67.9) 0.634 Side (left/right) 25 (58.1%) / 18 (41.9%) 28 (62.2%) / 17 (37.8%) 24 (46.2%) / 28 (53.8%) 77 (55.0%) / 63 (45.0%) 0.251 Age (years) 65.9 ± 7.0 (52-80) 67.9 ± 4.9 (58-76) 68.1 ± 5.5 (56-78) 67.4 ± 5.9 (52-80) 0.151 Height (cm) 161.6 ± 7.2 (150-175) 162.6 ± 7.4 (145-180) 162.3 ± 9.2 (145-188) 162.2 ± 8.0 (145-188) 0.822 Weight (kg) 72.8 ± 10.6 (55-105) 72.5 ± 12.8 (48-122) 72.1 ± 10.3 (55-100) 72.4 ± 11.2 (48-122) 0.958 BMI (kg/m²) 27.9 ± 3.5 (22.0-37.7) 27.3 ± 3.9 (18.3-39.4) 27.4 ± 3.3 (20.8-33.3) 27.5 ± 3.6 (18.3-39.4) 0.743 Pre-op HKA (°) 173.3 ± 7.2 (162.0-192.0) 174.3 ± 6.2 (165.8-196.8) 172.7 ± 4.9 (163.0-188.5) 173.4 ± 6.1 (162.0-196.8) 0.412 Follow-up (months) 22.8 ± 7.3 (12-37) 23.0 ± 4.1 (13-27) 22.6 ± 5.9 (12-34) 22.8 ± 5.9 (12-37) 0.951 In RA-O group, 4 cases have chosen surface geometry optimized femoral condyles for better flexion-extension balance, including 3 distal-thickened and 1 posterior-thickened implants. Table 2 showed the distribution of medial and lateral tibial inserts. Only 12 cases (27.9%) adopted exact symmetric medial and lateral inserts. To achieve medial-pivot kinematics, 7 cases (16.3%) used medial deep-dish insert. 13 cases (30.2%) applied inserts with different thickness, mostly 1mm thicker in the lateral side. Table 2. Distribution of medial and lateral tibial inserts in patient-specific implants Inserts L\M M standard (3°slope) M 6°slope M Deep-dish L Standard (3°slope) 8 (18.6%) 11(25.6%) 7(16.3%) L 6°slope 0 (0%) 4 (9.3%) 0 (0%) L standard +1mm 6 (14.0%) 3 (7.0%) 2 (4.7%) L standard -1mm 0 (0%) 0 (0%) 1 (2.3%) L 6°slope -1mm 0 (0%) 0 (0%) 1 (2.3%) M: medial L: lateral Standard: CR inserts with 3° posterior slope, similar to off-the shelf designs Deep-dish: inserts with deep-dish design, providing more congruency and restrictions. Postoperative radiographic assessment (Table 3) revealed significant differences among the three groups in both the postoperative HKA (P = 0.002) and the postoperative medial proximal tibial angle (MPTA) (P =0.002). Post-hoc analysis indicated that the RA-O Group achieved a significantly greater postoperative HKA and MPTA compared to both the RA-C and Manual Groups. Regarding patient-reported outcomes (Table 3), no significant inter-group differences were observed in any of the five KOOS subscales (Symptoms, Pain, Activities of Daily Living, Sports/Recreation, and Quality of Life. However, a significant difference was found in terms of Forgotten Joint Score-12 (FJS-12) (p = 0.04). Post-hoc comparison suggested significant difference between the RA-C group vs Manual group (p=0.012), while no statistical difference among the rest groups. Table 3. Post-operative radiographic assessments and patient-reported outcomes Variables RA-C Group (N=43) RA-O Group (N=45) Manual Group (N=52) Total (N=140) P value Post-op HKA (°) 178.2 ± 1.8 (175.0-183.0) 179.1 ± 3.3 (172.6-187.2) 177.4 ± 2.1 (173.0-185.0) 178.2 ± 2.6 (172.6-187.2) 0.002 c Post-op MPTA (°) 88.3 ± 1.2 (85.0-91.5) 89.5 ± 1.9 (85.7-92.9) 88.9 ± 1.6 (86.0-93.0) 88.9 ± 1.6 (85.0-93.0) 0.002 a KOOS-Symptom 91.4 ± 10.9 (53.6-100.0) 90.3 ± 9.8 (57.1-100.0) 93.2 ± 12.1 (39.3-100.0) 91.7 ± 11.0 (39.3-100.0) 0.426 KOOS-Pain 92.7 ± 9.7 (55.6-100.0) 92.1 ± 10.5 (55.6-100.0) 91.5 ± 13.0 (41.7-100.0) 92.1 ± 11.2 (41.7-100.0) 0.876 KOOS-Activities 87.2 ± 8.1 (45.6-94.1) 88.4 ± 14.5 (36.8-100.0) 85.9 ± 11.4 (30.9-94.1) 87.1 ± 11.6 (30.9-100.0) 0.588 KOOS-Sports 58.5 ± 13.7 (15.0-85.0) 52.2 ± 15.3 (15.0-85.0) 56.4 ± 14.5 (10.0-90.0) 55.7 ± 14.6 (10.0-90.0) 0.120 KOOS-Life Quality 80.1 ± 20.7 (6.3-100.0) 82.1 ± 22.5 (6.3-100.0) 76.7 ± 19.6 (0.0-100.0) 79.5 ± 20.9 (0.0-100.0) 0.436 FJS-12 78.0 ± 14.2 (43.8-100.0) 73.3 ± 24.7 (2.1-100.0) 67.4 ± 20.2 (0.0-100.0) 72.6 ± 20.5 (0.0-100.0) 0.04 b Satisfaction 0.002 ab Very Unsatisfied 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) Unsatisfied 0 (0.0%) 2 (4.4%) 2 (3.8%) 4 (2.9%) Neutral 1 (2.3%) 3 (6.7%) 1 (1.9%) 5 (3.6%) Satisfied 5 (11.6%) 17 (37.8%) 16 (30.8%) 38 (27.1%) Very Satisfied 37 (86.0%) 23 (51.1%) 33 (63.5%) 93 (66.4%) a: Significant difference between RA-C and RA-O group. b: Significant difference between RA-C and Manual group. c: Significant difference between RA-O and Manual group. The distribution of satisfaction levels (Table 3) differed significantly among the groups (P = 0.002). RA-C Group had the highest proportion of "Very Satisfied" responses (86.0%), and only one patient (2.3%) was “neutral”, with no dissatisfaction cases. In post-hoc test, RA-C group presented significant satisfaction comparing to both RA-O group (p=0.042) and Manual group (p<0.001), while no statistical difference was found between RA-C group and manual group (p=0.195). Discussions According to our findings, robotic TKA with patient-specific implants showed significant improved satisfaction, and thus may possibly further break the ceiling effect of robotics. Although FJS-12 did not show statistical difference between RA-C and RA-O group (78.0 vs 73.3), probably due to limited sample size, the overall satisfaction were siginificantly higher(97.6%) in the RA-C group. Additionally, the lower end of FJS-12(43.8) and satisfaction (only 1 neutral, no dissatisfaction) were also elevated. In contrast, although robotics alone showed slightly higher FJS-12 than manual group (while no statistical difference was found), the overall satisfaction did not improve. In assessment of post-operative radiology, RA-O group aquired more neutral HKA alignment and MTPA, probably due to intergroup heterogeneity. Since all procedures were performed by the same surgical team adhering to a unified alignment philosophy, we believe the difference in radiology would not translate to clinically meaningful differences in patient-reported outcomes. Our findings provided evidence that individualized implant design, rather than robotics alone, may be the more critical factor in optimizing TKA outcomes. Numerous studies reported that robotics alone has not consistently translated into superior clinical outcomes for TKA. A recent meta-analysis[ 23 ] with 1148 patients from 17 articles found no statistically significant difference in satisfaction rates between robotic-assisted TKA (95%) and conventional TKA (91%), despite robotic group demonstrating superior radiological precision. A large sample-sized randomized controlled trial (RCT) at minimum of 10-year follow-up by Kim et al[ 3 ] also found no difference between robotics and conventional TKA in terms of patient-reported outcomes, aseptic loosening and complications.Current robotic TKA systems primarily optimize bone resection plans through gap balancing under manual stress. While this allows surgeons to replicate their preferred alignment and balance targets, its precision is inherently limited by the unpredictable nature of pre-resection stress. Consequently, even achieving four “symmetric” medial and lateral gaps in extension and flexion does not guarantee a satisfactory outcome. Another critical limitation lies in patient-specific anatomy. As highlighted by a meta-analysis from Dobbelaere et al [ 11 ], high variation exists in sagittal femoral condylar radii-curvature, ranging from spherical to ovoid, while a surgeon typically prefers only one or two designs of implants, and may lead to mismatch and mid-flexion imbalance. Following initial bone-cut, uncorrected flexion contracture or unexpected hyperextension(especially in single-radii implants) are not rare. Additional bone-cut, soft-tissue releases or using thicker inserts may cause further instability or pain. Combining robotics with individulized implants could be one solution. Although extensive literature confirms the efficacy of customized TKA [ 24 , 15 , 25 – 27 ], manufacturers remain resistant to modifying femoral sagittal curvature. Most surgical robots are exclusively compatible with proprietary implants, creating integration barriers and specialized instrumentation deficits for customized prostheses. Conversely, the TiRicon system, while analogous to Mako in principle and practicing, accommodates diverse implant systems, enabling seamless integration with customized knee components. As is shown in our protocol, optimized femoral condyles could compensate for flexion-extension mismatch, rather than additional bone-cut or thicker liners; only 27.9% cases in our study adopted exact symmetric inserts, suggesting that minimal imbalance may still exist. Extension gap dedicates insert thickness, with maximum 1mm difference. Kinematics and stability decide slope and congruency of medial insert. In the beginning of our practice, several lateral inserts with 6° slope were adopted, while now we routinely use 3° laterally, as morphology of medial insert was more important than lateral. This stepwise methodology, termed "differential" TKA, integrates robotic assistance, quantified gap balancing, sequential bone cuts, and customized implants. Borrowed from mathematics, "differential" signifies optimizing outcomes through incremental adjustments. To improve clinical outcomes and reduce patient dissatisfaction, the future of TKA requires a pivotal paradigm shift from empirical to analytically driven practice. Limitations of our study include relatively small sample-size, limited follow-up duration, and non-prospective design. The long-term durability of the locking mechanism for separate tibial inserts warranted further validation. Moreover, the use of different robotic systems (TiRobot vs. Mako) with different implant surface geometry in the comparative groups was another limitation. While both robots are image-based semi-active systems, and all cases used Solver to quantify gap balancing, the confounding factor of different robots could be minimized. Future studies should control for the robotic platform and matched implant designs, employ randomized controlled trials and multi-center studies, to establish higher levels of evidence. Conclusions Synergizing robotic assistance with customized implants showed superior patient satisfaction and functional outcomes compared to robotic-assisted TKA with off-the-shelf implants and and manual TKA. Individualized implant design with more accurate guide of bone-cut, rather than robotics alone, may be the more critical factor in optimizing TKA outcomes.The findings support a paradigm shift in TKA from empirical, alignment-focused methods toward an analytical approach. Future studies should control for the robotic platform with matched implant designs, and employ prospective, multicenter randomized controlled trials, to establish higher-level evidence. Abbreviations TKA: total knee arthroplasty RA-C: robotic-assisted customized RA-O: robotic-assisted off-the-shelf HKA: hip-knee-ankle ACL: anterior cruciate ligament PCL: posterior cruciate ligament ADT: anterior drawer test KOOS: Knee Injury and Osteoarthritis Outcome Score FJS: Forgotten Joint Score Declarations Ethics approval and consent to participate: This research was approved by Ethics Committee of Beijing Jishuitan Hospital, Capital Medical University. Approval number was K2025-538-00. Informed consent to participate was obtained from all of the participants. Our study strictly adhered to the Declaration of Helsinki. Consent for publication: Written informed consent was obtained from all participants for publication of this research and any accompanying images. Competing interests: We declare that the authors have no competing interests. Funding: This research was supported by Beijing Natural Science Foundation (funding number :L254008) Author Contribution Hanlong Zheng wrote the main manuscript text , tables and prepared figure 2 to 4. Zhaolun Wang, Kaiding Wu and Jiajun Zheng performed patient follow-up. Hongyi Shao and Zhaolun Wang provided help for statistical analysis. Yixin Zhou and Ji Zhang andperformed all surgeries in this study, utilizing similar surgical concepts. Yixin Zhou initiated the core concept of "Analitycal TKA", provided figure 1 and figure 5, and made substantial revisions for this manuscript. All authors reviewed the manuscript. Acknowledgements: None Data Availability We do not have any research data outside the submitted manuscript file. Orignal data could be aquired by e-mailing the corresponding author. References Flierl MA, Sobh AH, Culp BM, Baker EA, Sporer SM. Evaluation of the Painful Total Knee Arthroplasty. 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Patient-specific implants with custom cutting blocks better approximate natural knee kinematics than standard TKA without custom cutting blocks. Knee. 2015;22:624–9. https://doi.org/10.1016/j.knee.2015.08.002 . Ivie CB, Probst PJ, Bal AK, Stannard JT, Crist BD, et al. Improved Radiographic Outcomes With Patient-Specific Total Knee Arthroplasty. J Arthroplasty. 2014;29:2100–3. https://doi.org/10.1016/j.arth.2014.06.024 . Schroeder L, Dunaway A, Dunaway D. (2022) A Comparison of Clinical Outcomes and Implant Preference of Patients with Bilateral TKA. JBJS Rev 10. https://doi.org/10.2106/jbjs.Rvw.20.00182 Arnholdt J, Kamawal Y, Horas K, Holzapfel BM, Gilbert F, et al. Accurate implant fit and leg alignment after cruciate-retaining patient-specific total knee arthroplasty. BMC Musculoskelet Disord 21. 2020. https://doi.org/10.1186/s12891-020-03707-2 . Zeller IM, Sharma A, Kurtz WB, Anderle MR, Komistek RD. Customized versus Patient-Sized Cruciate-Retaining Total Knee Arthroplasty: An In Vivo Kinematics Study Using Mobile Fluoroscopy. J Arthroplasty. 2017;32:1344–50. https://doi.org/10.1016/j.arth.2016.09.034 . Culler SD, Martin GM, Swearingen A. Comparison of adverse events rates and hospital cost between customized individually made implants and standard off-the-shelf implants for total knee arthroplasty. Arthroplasty Today. 2017;3:257–63. https://doi.org/10.1016/j.artd.2017.05.001 . Schwarzkopf R, Brodsky M, Garcia GA, Gomoll AH. Surgical and Functional Outcomes in Patients Undergoing Total Knee Replacement With Patient-Specific Implants Compared With Off-the-Shelf Implants. Orthop J Sports Med. 2015;3. https://doi.org/10.1177/2325967115590379 . Victor J, Vermue H. Custom TKA: what to expect and where do we stand today? Arch Orthop Trauma Surg. 2021;141:2195–203. https://doi.org/10.1007/s00402-021-04038-0 . Wendelspiess S, Kaelin R, Vogel N, Rychen T, Arnold MP. No difference in patient-reported satisfaction after 12 months between customised individually made and off‐the‐shelf total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc. 2022;30:2948–57. https://doi.org/10.1007/s00167-022-06900-z . Chen M, Yang D, Shao H, Rui S, Cao Y, et al. Using sequential bone cutting to titrate soft tissue balance in total knee arthroplasty effectively minimizes soft tissue release. BMC Musculoskelet Disord 24. 2023. https://doi.org/10.1186/s12891-023-07005-5 . Hoveidaei AH, Esmaeili S, Ghaseminejad-Raeini A, Pirahesh K, Fallahi MS, et al. Robotic assisted Total Knee Arthroplasty (TKA) is not associated with increased patient satisfaction: a systematic review and meta-analysis. Int Orthop. 2024;48:1771–84. https://doi.org/10.1007/s00264-024-06206-4 . Steinert AF, Schröder L, Sefrin L, Janßen B, Arnholdt J, et al. The Impact of Total Knee Replacement with a Customized Cruciate-Retaining Implant Design on Patient-Reported and Functional Outcomes. J Pers Med 12. 2022. https://doi.org/10.3390/jpm12020194 . Schroeder L, Pumilia CA, Sarpong NO, Martin G. Patient Satisfaction, Functional Outcomes, and Implant Survivorship in Patients Undergoing Customized Cruciate-Retaining TKA. JBJS Reviews. 2021;9. 00077.https://doi.org/10.2106/jbjs.Rvw.20.00074 . :e20.00074-. Moret CS, Schelker BL, Hirschmann MT. Clinical and Radiological Outcomes after Knee Arthroplasty with Patient-Specific versus Off-the-Shelf Knee Implants: A Systematic Review. J Pers Med 11. 2021. https://doi.org/10.3390/jpm11070590 . Moret CS, Hirschmann MT, Vogel N, Arnold MP. Customised, individually made total knee arthroplasty shows promising 1-year clinical and patient reported outcomes. Arch Orthop Trauma Surg. 2021;141:2217–25. https://doi.org/10.1007/s00402-021-04045-1 . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 11 Apr, 2026 Reviews received at journal 08 Apr, 2026 Reviews received at journal 07 Apr, 2026 Reviewers agreed at journal 06 Apr, 2026 Reviewers agreed at journal 06 Apr, 2026 Reviews received at journal 04 Apr, 2026 Reviewers agreed at journal 04 Apr, 2026 Reviewers agreed at journal 03 Apr, 2026 Reviews received at journal 03 Apr, 2026 Reviewers agreed at journal 03 Apr, 2026 Reviewers agreed at journal 03 Apr, 2026 Reviewers agreed at journal 02 Apr, 2026 Reviewers agreed at journal 01 Apr, 2026 Reviewers invited by journal 01 Apr, 2026 Editor assigned by journal 18 Mar, 2026 Submission checks completed at journal 17 Mar, 2026 First submitted to journal 14 Mar, 2026 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-9065050","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":617589533,"identity":"e8266020-5027-4113-a8a8-a00b5629299e","order_by":0,"name":"Hanlong Zheng","email":"","orcid":"","institution":"Beijing Jishuitan Hospital, Capital Medical University, National Center for Orthopaedics","correspondingAuthor":false,"prefix":"","firstName":"Hanlong","middleName":"","lastName":"Zheng","suffix":""},{"id":617589534,"identity":"60190a8c-83ba-440d-86a8-8fa0d16378a2","order_by":1,"name":"Zhaolun Wang","email":"","orcid":"","institution":"Beijing Jishuitan Hospital, Capital Medical University, National Center for Orthopaedics","correspondingAuthor":false,"prefix":"","firstName":"Zhaolun","middleName":"","lastName":"Wang","suffix":""},{"id":617589536,"identity":"a3ba8be3-60a4-4fb6-ba0d-599a222f2bf5","order_by":2,"name":"Ji Zhang","email":"","orcid":"","institution":"Beijing Jishuitan Hospital, Capital Medical University, National Center for Orthopaedics","correspondingAuthor":false,"prefix":"","firstName":"Ji","middleName":"","lastName":"Zhang","suffix":""},{"id":617589537,"identity":"46e0e0c2-f192-4acd-befe-e77fd562d01a","order_by":3,"name":"Kaiding Wu","email":"","orcid":"","institution":"Beijing Jishuitan Hospital, Capital Medical University, National Center for Orthopaedics","correspondingAuthor":false,"prefix":"","firstName":"Kaiding","middleName":"","lastName":"Wu","suffix":""},{"id":617589538,"identity":"fa0622f3-9826-4533-9758-e2484dea0edb","order_by":4,"name":"Jiajun Zheng","email":"","orcid":"","institution":"Beijing Jishuitan Hospital, Capital Medical University, National Center for Orthopaedics","correspondingAuthor":false,"prefix":"","firstName":"Jiajun","middleName":"","lastName":"Zheng","suffix":""},{"id":617589539,"identity":"51e71009-2b74-49d0-bb14-d686485e0050","order_by":5,"name":"Hongyi Shao","email":"","orcid":"","institution":"Beijing Jishuitan Hospital, Capital Medical University, National Center for Orthopaedics","correspondingAuthor":false,"prefix":"","firstName":"Hongyi","middleName":"","lastName":"Shao","suffix":""},{"id":617589540,"identity":"086a9049-41cf-4e23-9ab3-7a9a42caf1a2","order_by":6,"name":"Yixin Zhou","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA00lEQVRIiWNgGAWjYHACNiCWAJLMBxgYG4jSwQzTwpZAkhYQ4DEgTgu/9PljDz62WST2Sfd8k/i5w0aOgf3w0Q34tEj2JbMbzmyTMGaTObtNsvdMmjEDT1raDXxaDM4ws0nztknIsUnkbpPgbTuc2CDBY0aUFh42iZxnkn9J0QK0JQfEIEKLZA+zmeSMc0C/SKQZW8u2pRmzEfILPw/jM4kPZXWJ82ckP7z5ts1Gjp/98DG8WsCAERI1LBIgkg2vUjj4AyaZPxCnehSMglEwCkYaAADkbj6BSQ1YOgAAAABJRU5ErkJggg==","orcid":"","institution":"Beijing Jishuitan Hospital, Capital Medical University, National Center for Orthopaedics","correspondingAuthor":true,"prefix":"","firstName":"Yixin","middleName":"","lastName":"Zhou","suffix":""}],"badges":[],"createdAt":"2026-03-08 14:54:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9065050/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9065050/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106309597,"identity":"d6a60f43-477a-4fbd-9f9f-2dd972247419","added_by":"auto","created_at":"2026-04-07 10:18:41","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":47596,"visible":true,"origin":"","legend":"\u003cp\u003eThe design of patient-specific implants.\u003c/p\u003e\n\u003cp\u003e1a: based on off-the shelf geometry of A3GT, bony coverage was initially personalized. 1b: Sagittal surface geometry of posterior-thickeded femoral condyle. Modified part was marked yellow. 1c: Sagittal surface geometry of distal-thickeded femoral condyle. Instead of changing condyle curvature, we proximized the internal bone-cut surface by 1.5mm, marked orange.\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9065050/v1/1d5922f9551ca12023631596.jpg"},{"id":106403338,"identity":"ab0b0c2b-1723-4c15-986b-72373a72402c","added_by":"auto","created_at":"2026-04-08 09:14:06","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":96205,"visible":true,"origin":"","legend":"\u003cp\u003eRobotic procedures, gap balancing and pre-cutting trials.\u003c/p\u003e\n\u003cp\u003e2a: TiRobot Recon system based on pre-operative CT scan. 2b: We routinely use Solver to quantify gap-force balancing with an universally-adapted pre-cutting trial. 2c: implanted patient-specific prosthesis could well-adapt patient’s anatomy with perfect coverage. Yellow arrow showed medial deep-dish insert.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9065050/v1/db2fa858c5310de98ccde1c3.jpg"},{"id":106404348,"identity":"af94f72a-221a-4b58-8ffc-dbedf1853c6e","added_by":"auto","created_at":"2026-04-08 09:15:51","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":68761,"visible":true,"origin":"","legend":"\u003cp\u003eQuantifed gap-force balance and kinematics.\u003c/p\u003e\n\u003cp\u003e3a: gap-force matrix of the Solver. With increasingly exerted force (from 30N to 90N), the matrix could quantify medial-lateral balance and elastic modulus of collateral ligaments, deciding bone-cut adjustment or soft-tissue release, if necessary. This balance graph showed that the extension gap was symmetric, and the flexion gap remained physiological lateral laxity. 3b: intraoperative kinematics of tibia-femoral track from extension to flexion. 3c: Anterior drawer test.\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9065050/v1/a383d9c38f301c69ba6715ce.jpg"},{"id":106309594,"identity":"38ab229a-78af-4caf-87e8-56bf35f35ab2","added_by":"auto","created_at":"2026-04-07 10:18:40","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":93125,"visible":true,"origin":"","legend":"\u003cp\u003eProtocol for implant section in robotic-assisted customized TKA.\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9065050/v1/e5a762b8fe2ff451547e75ef.jpg"},{"id":106309598,"identity":"2c53c526-2561-49fd-861f-04245818c1d2","added_by":"auto","created_at":"2026-04-07 10:18:41","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":81579,"visible":true,"origin":"","legend":"\u003cp\u003eflowchart of patient selection\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9065050/v1/7479f5bc55c514e047590e0c.jpg"},{"id":106405705,"identity":"260139c7-7d1f-469b-ae2a-d155afa97ee6","added_by":"auto","created_at":"2026-04-08 09:28:19","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1216499,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9065050/v1/ad6cebb9-07dc-49c7-8858-0f1bba9aacb5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"From Empirical to Analytical: Synergizing Robotic Assistance with Customized Implants for Superior TKA Outcomes","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSoft-tissue imbalance remains one of the leading causes of postoperative dissatisfaction in total knee arthroplasty (TKA) [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. With the development of robotic technology, the paradigms of TKA alignment have been changing from mechanical alignment to functional /kinematic alignment, potentially reducing soft-tissue releases, achieving better gap balance while respecting alignment boundary[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. However, whether robotics alone can consistently improve patient satisfaction and functional outcomes remains controversial [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. A fundamental challenge lies in the discrepancy between standardized implants and individual anatomy: while anatomical morphology and soft-tissue elasticity exhibit significant variability among individuals [\u003cspan additionalcitationids=\"CR7 CR8 CR9 CR10\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], prosthetic geometries are typically standardized. Consequently, this mismatch generates kinematic conflicts\u0026mdash;defined as the disharmony between the motion dictated by the implant's geometry and the natural kinematics guided by the patient's soft-tissue envelope\u0026mdash;which may contribute to mid-flexion instability, stiffness, and persistent pain [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWhile patient-specific TKA implants have emerged to address these challenges[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], current applications often fall short of functional restoration [\u003cspan additionalcitationids=\"CR16 CR17 CR18\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Critically, most systems achieve only 'implant individualization' in terms of morphological fit (bony coverage) while retaining standardized articular curvatures, thus failing to address the underlying kinematic mismatch. Moreover, reliance on conventional instruments or static patient-specific guides (PSI) restricts restricts the surgery to a purely mechanical process, denying surgeons the ability to perform intraoperative quantitative analysis or apply mathematical decision-making, rendering personalized, dynamic optimization of the joint gap impossible [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOur team initially synergized robotics and customized implants in TKA procedure, in an 'Analytical' approach. Utilizing a CT-based system integrated with quantitative gap-force sensors, this approach employs a novel modular implant system designed for independent medial-lateral optimization. On the tibial side, surgeons can independently select and combine medial and lateral inserts\u0026mdash;varying in thickness, congruency, and posterior slope\u0026mdash;based on real-time intraoperative sensor data. On the femoral side, distal condylar and posterior condylar thickness could also be modifyed. By synergizing this analytical workflow with the implant\u0026rsquo;s comprehensive modularity, surgeons can achieve a multi-factorial optimization of the joint\u0026mdash;balancing gap tension, surface geometry, and rotational kinematics simultaneously. However, comparative evidence supporting the clinical superiority of this technique remains limited.\u003c/p\u003e \u003cp\u003eConsequently, the objective of this study was to evaluate whether this shift from empirical to analytical surgery translates to clinical benefit. We compared patient satisfaction, functional scores, and radiological outcomes across three distinct approaches: Analytical TKA with patient-specific implants (RA-C), robotic-assisted TKA with off-the-shelf implants (RA-O), and conventional manual TKA with off-the-shelf implants (Manual). We hypothesized that the Analytical TKA approach, by synergizing intraoperative quantitative balancing with geometric customization, would effectively mitigate kinematic conflicts and yield superior patient satisfaction compared to standard off-the-shelf techniques.\u003c/p\u003e"},{"header":"Patients and Methods","content":"\u003cp\u003e\u003cstrong\u003ePatient Selection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis retrospective-cohort study was approved by the institutional review board (IRB) of our institute. Patients who underwent TKA between Dec 2022 and Dec 2024 were enrolled and divided into 3 sub-groups: Robotic-assisted TKA with customized implants (RA-C), Robotic-assisted TKA with off-the-shelf implants (RA-O), Manual TKA with off-the-shelf implants (Manual).\u003c/p\u003e\n\u003cp\u003eInclusion Criteria：\u003c/p\u003e\n\u003cp\u003e1.Patients aged 50 to 80 years.\u003c/p\u003e\n\u003cp\u003e2.Varus or flexion deformity \u0026lt; 25°, and valgus deformity \u0026lt; 20°.\u003c/p\u003e\n\u003cp\u003e3.For subgroup allocation:\u003c/p\u003e\n\u003cp\u003eRA-C Group: Robotic-assisted TKA using AK (AK Medical, Beijing, China) customized cruciate-retaining (CR)implants.\u003c/p\u003e\n\u003cp\u003eRA-O Group: Robotic-assisted TKA with the MAKO system and cruciate-retaining (CR) implants.\u003c/p\u003e\n\u003cp\u003eManual Group: Manual TKA with an A3GT (AK Medical, Beijing, China) CR prosthesis.\u003c/p\u003e\n\u003cp\u003eExclusion Criteria：\u003c/p\u003e\n\u003cp\u003e1.Knee instability or posterior cruciate ligament (PCL) deficiency contraindicating a cruciate-retaining (CR) TKA procedure.\u003c/p\u003e\n\u003cp\u003e2.Incomplete data.\u003c/p\u003e\n\u003cp\u003e3.Inability or unwillingness to comply with follow-up assessments.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eImplant Customization\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients in RA-C group underwent hip-knee-ankle CT scans twelve weeks before surgery, both for robotic planning and implant customization. Utilizing CAD software for 3-D modeling, surface geometry designs were based on the of their off-the-shelf product (A3GT, AK Medical, Beijing, China), modifying the anteroposterior (AP) and mediolateral (ML) dimensions as well as anterior flange, to acquire best bony coverage. If a patient presented with knee laxity, hyperextension, we prepare implants and trial components with a 1.5 mm thickening of the distal femur; In severe flexion deformity, 2mm thickening posterior condyle would be additionally perpared, to well-adapt the flexion-extension mismatch. The curvature transition areas were smoothed, and the surgeon had alternative options for femoral condyles based on intraoperative balancing. The customization of tibial tray was achieved by optimizing best coverage, with separately designed medial and lateral tibial inserts. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSurgical Procedures\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRA-C group\u003c/p\u003e\n\u003cp\u003eAll procedures were performed using TiRobot Recon system, based on hip-knee-ankle CT scans. A mid-patellar approach was used, osteophytes were initially removed, and the anterior cruciate ligament (ACL) was excised. After registration, the maximum medial and lateral gaps during knee flexion and extension were captured, and the surgical plan was adjusted using a \"titration\" of sequential bone-cutting technique[22] (Fig.2). The robot’s starting alignment was mechanical, and boundary of alignment was 4 degrees on the tibia and 5 degrees in total. Bone-cut of distal femur, posterior condyles, posterior chamfer and tibia were initially performed, medial and lateral meniscus were excised, leaving the anterior femoral cortex and anterior chamfer untouched, allowing for further possible adjustments. A \"pre-cutting\" femoral trial component was inserted, sharing the same surface geometry as the distal and posterior part of A3GT condyle, while 2 mm thinner in general, without anterior flange or chamfer.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTo quantify gap-forcing balance, Solver (Tinavi Beijing, China) were employed [22, 9], calculating absolute gaps at certain force and elastic modulus of collateral ligaments (Fig.3). According to the matrix of the Solver, if necessary, surgeons will do a secondary adjustment and finish the whole bone-cut of the femur. Trials were then implanted to assess medial/lateral gaps and tibiofemoral kinematics. Anterior drawer test (ADT) were also captured to evaluate anteroposterior translation.\u003c/p\u003e\n\u003cp\u003eIn RA-C group, our protocol for implant section was shown in Figure 4. Optimized femorl condyles were provided for extension-flexion eqality. Different thicknesses (8–14 mm), posterior slopes (3° or 6°), and deep-dish constrained liners could be selected to optimize balance, kinematics and stability.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eRA-O group\u003c/p\u003e\n\u003cp\u003eAll surgeries in RA-O group were performed using Mako system. Surgical approach, robotic manipulation and alignment boundary were similar. To minimize the confounding factors of different robots and gap-balancing techniques, Solver was also adopted in this group. Triathlon CR implants were used, with the 9mm, 11mm and 13mm thickness of tibial inserts eligible.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eManual group\u003c/p\u003e\n\u003cp\u003eAll patients underwent manual TKA used A3GT prosthesis (AK medical, Beijing China). This multi-radius designed implant was the prototype of customized implants in our study. Surgical approach was identical to other groups. Femoral bone-cut employed intramedullary guidance, while tibial bone-cut used extramedullary guidance, both utilizing measured resection techniques starting with mechanical alignment, although a maximum of 5 degrees residual was permitted. Gap balancing was assessed using spacer blocks. Inserts with 8mm, 10mm and 12mm were eligible, all of which were designed 3 degrees’ slope.\u003c/p\u003e\n\u003cp\u003eAll operations in our study were performed by two experienced surgeons who shared the same surgical philosophy and alignment preference. The posterior cruciate ligament (PCL) was preserved in all cases, and no patellar resurfacing was performed. All implants were cemented.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Collection \u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatient demographic data were collected, including gender, age, height, weight, BMI, and preoperative alignment. Postoperative follow-up included patient satisfaction (categorized as very dissatisfied, dissatisfied, neutral, satisfied, or very satisfied), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Forgotten Joint Score (FJS). Post-operative radiographic analysis included the overall hip-knee-ankle (HKA) alignment and medial proximal tibial angle (MPTA).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data were analyzed using SPSS version 22.0. Analysis of variance (ANOVA) was used to compare continuous variables among the three groups, post hoc pairwise comparisons were performed using the Least Significant Difference (LSD) test. Categorical variables were analyzed using the chi-square test. Satisfaction grades were compared using the Kruskal-Wallis H test, and post-hoc pairwise comparisons were performed using Mann-Whitney U test with Bonferroni correction (where the p-value was multiplied by 3 to account for the three pairwise tests). Statistical significance was determined at the p \u0026lt; 0.05 level.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 140 patients (150 knees) met inclusion criteria, and 10 patients were excluded.The final enrollment (Figure 5) included 43 knees in RA-O group, 45 knees in RA-C group and 52 knees in Manual group.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePatient demographics were shown in Table 1. Baseline characteristics of the three groups were compared. No statistically significant differences were found in terms of gender, operative side, age, height, weight, body mass index (BMI), preoperative hip-knee-ankle angle (HKA), or follow-up duration.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1. Patient demographics\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.2957%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eVariables\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.9946%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRA-C Group (N=43)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.2634%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRA-O Group (N=45)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.6667%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eManual Group (N=52)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.7258%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTotal (N=140)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.0538%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eP value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.2957%;\"\u003e\n \u003cp\u003eGender (Male/Female)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.9946%;\"\u003e\n \u003cp\u003e15 (34.9) / 28 (65.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.2634%;\"\u003e\n \u003cp\u003e12 (26.7) / 33 (73.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.6667%;\"\u003e\n \u003cp\u003e18 (34.6) / 34 (65.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.7258%;\"\u003e\n \u003cp\u003e45 (32.1) / 95 (67.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.0538%;\"\u003e\n \u003cp\u003e0.634\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.2957%;\"\u003e\n \u003cp\u003eSide (left/right)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.9946%;\"\u003e\n \u003cp\u003e25 (58.1%) / 18 (41.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.2634%;\"\u003e\n \u003cp\u003e28 (62.2%) / 17 (37.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.6667%;\"\u003e\n \u003cp\u003e24 (46.2%) / 28 (53.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.7258%;\"\u003e\n \u003cp\u003e77 (55.0%) / 63 (45.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.0538%;\"\u003e\n \u003cp\u003e0.251\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.2957%;\"\u003e\n \u003cp\u003eAge (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.9946%;\"\u003e\n \u003cp\u003e65.9 \u0026plusmn; 7.0\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(52-80)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.2634%;\"\u003e\n \u003cp\u003e67.9 \u0026plusmn; 4.9\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(58-76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.6667%;\"\u003e\n \u003cp\u003e68.1 \u0026plusmn; 5.5\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(56-78)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.7258%;\"\u003e\n \u003cp\u003e67.4 \u0026plusmn; 5.9\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(52-80)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.0538%;\"\u003e\n \u003cp\u003e0.151\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.2957%;\"\u003e\n \u003cp\u003eHeight (cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.9946%;\"\u003e\n \u003cp\u003e161.6 \u0026plusmn; 7.2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(150-175)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.2634%;\"\u003e\n \u003cp\u003e162.6 \u0026plusmn; 7.4\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(145-180)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.6667%;\"\u003e\n \u003cp\u003e162.3 \u0026plusmn; 9.2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(145-188)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.7258%;\"\u003e\n \u003cp\u003e162.2 \u0026plusmn; 8.0\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(145-188)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.0538%;\"\u003e\n \u003cp\u003e0.822\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.2957%;\"\u003e\n \u003cp\u003eWeight (kg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.9946%;\"\u003e\n \u003cp\u003e72.8 \u0026plusmn; 10.6\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(55-105)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.2634%;\"\u003e\n \u003cp\u003e72.5 \u0026plusmn; 12.8\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(48-122)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.6667%;\"\u003e\n \u003cp\u003e72.1 \u0026plusmn; 10.3\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(55-100)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.7258%;\"\u003e\n \u003cp\u003e72.4 \u0026plusmn; 11.2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(48-122)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.0538%;\"\u003e\n \u003cp\u003e0.958\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.2957%;\"\u003e\n \u003cp\u003eBMI (kg/m\u0026sup2;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.9946%;\"\u003e\n \u003cp\u003e27.9 \u0026plusmn; 3.5\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(22.0-37.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.2634%;\"\u003e\n \u003cp\u003e27.3 \u0026plusmn; 3.9\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(18.3-39.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.6667%;\"\u003e\n \u003cp\u003e27.4 \u0026plusmn; 3.3\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(20.8-33.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.7258%;\"\u003e\n \u003cp\u003e27.5 \u0026plusmn; 3.6\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(18.3-39.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.0538%;\"\u003e\n \u003cp\u003e0.743\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.2957%;\"\u003e\n \u003cp\u003ePre-op HKA (\u0026deg;)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.9946%;\"\u003e\n \u003cp\u003e173.3 \u0026plusmn; 7.2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(162.0-192.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.2634%;\"\u003e\n \u003cp\u003e174.3 \u0026plusmn; 6.2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(165.8-196.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.6667%;\"\u003e\n \u003cp\u003e172.7 \u0026plusmn; 4.9\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(163.0-188.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.7258%;\"\u003e\n \u003cp\u003e173.4 \u0026plusmn; 6.1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(162.0-196.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.0538%;\"\u003e\n \u003cp\u003e0.412\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.2957%;\"\u003e\n \u003cp\u003eFollow-up (months)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.9946%;\"\u003e\n \u003cp\u003e22.8 \u0026plusmn; 7.3\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(12-37)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.2634%;\"\u003e\n \u003cp\u003e23.0 \u0026plusmn; 4.1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(13-27)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.6667%;\"\u003e\n \u003cp\u003e22.6 \u0026plusmn; 5.9\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(12-34)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.7258%;\"\u003e\n \u003cp\u003e22.8 \u0026plusmn; 5.9\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(12-37)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 15.0538%;\"\u003e\n \u003cp\u003e0.951\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eIn RA-O group, 4 cases have chosen surface geometry optimized femoral condyles for better flexion-extension balance, including 3 distal-thickened and 1 posterior-thickened implants. Table 2 showed the distribution of medial and lateral tibial inserts. Only 12 cases (27.9%) adopted exact symmetric medial and lateral inserts. To achieve medial-pivot kinematics, 7 cases (16.3%) used medial deep-dish insert. 13 cases (30.2%) applied inserts with different thickness, mostly 1mm thicker in the lateral side.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2. Distribution of medial and lateral tibial inserts in patient-specific implants\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 21.4106%;\"\u003e\n \u003cp\u003eInserts\u003c/p\u003e\n \u003cp\u003eL\\M\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003eM standard\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(3\u0026deg;slope)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003eM 6\u0026deg;slope\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003eM Deep-dish\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 21.4106%;\"\u003e\n \u003cp\u003eL Standard\u003c/p\u003e\n \u003cp\u003e(3\u0026deg;slope)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e8 (18.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e11(25.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e7(16.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 21.4106%;\"\u003e\n \u003cp\u003eL 6\u0026deg;slope\u003c/p\u003e\u0026nbsp;\u0026nbsp;\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e0 (0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e4 (9.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e0 (0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 21.4106%;\"\u003e\n \u003cp\u003eL standard\u003c/p\u003e\n \u003cp\u003e+1mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e6 (14.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e3 (7.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e2 (4.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 21.4106%;\"\u003e\n \u003cp\u003eL standard\u003c/p\u003e\n \u003cp\u003e-1mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e0 (0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e0 (0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e1 (2.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 21.4106%;\"\u003e\n \u003cp\u003eL 6\u0026deg;slope\u003c/p\u003e\n \u003cp\u003e-1mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e0 (0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e0 (0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.1965%;\"\u003e\n \u003cp\u003e1 (2.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eM: medial\u003c/p\u003e\n\u003cp\u003eL: lateral\u003c/p\u003e\n\u003cp\u003eStandard: CR inserts with 3\u0026deg; posterior slope, similar to off-the shelf designs\u003c/p\u003e\n\u003cp\u003eDeep-dish: inserts with deep-dish design, providing more congruency and restrictions.\u003c/p\u003e\n\u003cp\u003ePostoperative radiographic assessment (Table 3) revealed significant differences among the three groups in both the postoperative HKA (P = 0.002) and the postoperative medial proximal tibial angle (MPTA) (P =0.002). Post-hoc analysis indicated that the RA-O Group achieved a significantly greater postoperative HKA and MPTA compared to both the RA-C and Manual Groups. Regarding patient-reported outcomes (Table 3), no significant inter-group differences were observed in any of the five KOOS subscales (Symptoms, Pain, Activities of Daily Living, Sports/Recreation, and Quality of Life. However, a significant difference was found in terms of Forgotten Joint Score-12 (FJS-12) (p = 0.04). Post-hoc\u0026nbsp;comparison suggested significant difference between the RA-C group vs Manual group (p=0.012), while no statistical difference among the rest groups.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3. Post-operative radiographic assessments and patient-reported outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eVariables\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRA-C Group (N=43)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRA-O Group (N=45)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eManual Group (N=52)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTotal\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(N=140)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eP value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePost-op HKA (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e178.2 \u0026plusmn; 1.8\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(175.0-183.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e179.1 \u0026plusmn; 3.3\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(172.6-187.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e177.4 \u0026plusmn; 2.1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(173.0-185.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e178.2 \u0026plusmn; 2.6\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(172.6-187.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.002\u003csup\u003ec\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePost-op MPTA (\u0026deg;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e88.3 \u0026plusmn; 1.2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(85.0-91.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e89.5 \u0026plusmn; 1.9\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(85.7-92.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e88.9 \u0026plusmn; 1.6\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(86.0-93.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e88.9 \u0026plusmn; 1.6\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(85.0-93.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.002\u003csup\u003ea\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eKOOS-Symptom\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e91.4 \u0026plusmn; 10.9\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(53.6-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e90.3 \u0026plusmn; 9.8\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(57.1-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e93.2 \u0026plusmn; 12.1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(39.3-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e91.7 \u0026plusmn; 11.0\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(39.3-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e0.426\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eKOOS-Pain\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e92.7 \u0026plusmn; 9.7\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(55.6-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e92.1 \u0026plusmn; 10.5\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(55.6-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e91.5 \u0026plusmn; 13.0\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(41.7-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e92.1 \u0026plusmn; 11.2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(41.7-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e0.876\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eKOOS-Activities\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e87.2 \u0026plusmn; 8.1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(45.6-94.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e88.4 \u0026plusmn; 14.5\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(36.8-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e85.9 \u0026plusmn; 11.4\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(30.9-94.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e87.1 \u0026plusmn; 11.6\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(30.9-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e0.588\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eKOOS-Sports\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e58.5 \u0026plusmn; 13.7\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(15.0-85.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e52.2 \u0026plusmn; 15.3\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(15.0-85.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e56.4 \u0026plusmn; 14.5\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(10.0-90.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e55.7 \u0026plusmn; 14.6\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(10.0-90.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e0.120\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eKOOS-Life Quality\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e80.1 \u0026plusmn; 20.7\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(6.3-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e82.1 \u0026plusmn; 22.5\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(6.3-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e76.7 \u0026plusmn; 19.6\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.0-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e79.5 \u0026plusmn; 20.9\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.0-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e0.436\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFJS-12\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e78.0 \u0026plusmn; 14.2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(43.8-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e73.3 \u0026plusmn; 24.7\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(2.1-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e67.4 \u0026plusmn; 20.2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.0-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e72.6 \u0026plusmn; 20.5\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.0-100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.04\u003csup\u003eb\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSatisfaction\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e \u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e \u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e \u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e \u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.002\u003csup\u003eab\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eVery Unsatisfied\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e0 (0.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e0 (0.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e0 (0.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e0 (0.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e \u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eUnsatisfied\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e0 (0.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e2 (4.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e2 (3.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e4 (2.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e \u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eNeutral\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e1 (2.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e3 (6.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e1 (1.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e5 (3.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e \u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSatisfied\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e5 (11.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e17 (37.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e16 (30.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e38 (27.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e \u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.8845%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eVery Satisfied\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e37 (86.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.231%;\"\u003e\n \u003cp\u003e23 (51.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.3141%;\"\u003e\n \u003cp\u003e33 (63.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.7726%;\"\u003e\n \u003cp\u003e93 (66.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd nowrap=\"\" valign=\"top\" style=\"width: 9.56679%;\"\u003e\n \u003cp\u003e \u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003ea: Significant difference between RA-C and RA-O group.\u003c/p\u003e\n\u003cp\u003eb: Significant difference between RA-C and Manual group.\u003c/p\u003e\n\u003cp\u003ec: Significant difference between RA-O and Manual group.\u003c/p\u003e\n\u003cp\u003eThe distribution of satisfaction levels (Table 3) differed significantly among the groups (P = 0.002). RA-C Group had the highest proportion of \u0026quot;Very Satisfied\u0026quot; responses (86.0%), and only one patient (2.3%) was \u0026ldquo;neutral\u0026rdquo;, with no dissatisfaction cases. In post-hoc test, RA-C group presented significant satisfaction comparing to both RA-O group (p=0.042) and Manual group (p\u0026lt;0.001), while no statistical difference was found between RA-C group and manual group (p=0.195).\u003c/p\u003e"},{"header":"Discussions","content":"\u003cp\u003eAccording to our findings, robotic TKA with patient-specific implants showed significant improved satisfaction, and thus may possibly further break the ceiling effect of robotics. Although FJS-12 did not show statistical difference between RA-C and RA-O group (78.0 vs 73.3), probably due to limited sample size, the overall satisfaction were siginificantly higher(97.6%) in the RA-C group. Additionally, the lower end of FJS-12(43.8) and satisfaction (only 1 neutral, no dissatisfaction) were also elevated. In contrast, although robotics alone showed slightly higher FJS-12 than manual group (while no statistical difference was found), the overall satisfaction did not improve. In assessment of post-operative radiology, RA-O group aquired more neutral HKA alignment and MTPA, probably due to intergroup heterogeneity. Since all procedures were performed by the same surgical team adhering to a unified alignment philosophy, we believe the difference in radiology would not translate to clinically meaningful differences in patient-reported outcomes. Our findings provided evidence that individualized implant design, rather than robotics alone, may be the more critical factor in optimizing TKA outcomes.\u003c/p\u003e \u003cp\u003eNumerous studies reported that robotics alone has not consistently translated into superior clinical outcomes for TKA. A recent meta-analysis[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e] with 1148 patients from 17 articles found no statistically significant difference in satisfaction rates between robotic-assisted TKA (95%) and conventional TKA (91%), despite robotic group demonstrating superior radiological precision. A large sample-sized randomized controlled trial (RCT) at minimum of 10-year follow-up by Kim et al[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] also found no difference between robotics and conventional TKA in terms of patient-reported outcomes, aseptic loosening and complications.Current robotic TKA systems primarily optimize bone resection plans through gap balancing under manual stress. While this allows surgeons to replicate their preferred alignment and balance targets, its precision is inherently limited by the unpredictable nature of pre-resection stress. Consequently, even achieving four \u0026ldquo;symmetric\u0026rdquo; medial and lateral gaps in extension and flexion does not guarantee a satisfactory outcome. Another critical limitation lies in patient-specific anatomy. As highlighted by a meta-analysis from Dobbelaere et al [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], high variation exists in sagittal femoral condylar radii-curvature, ranging from spherical to ovoid, while a surgeon typically prefers only one or two designs of implants, and may lead to mismatch and mid-flexion imbalance. Following initial bone-cut, uncorrected flexion contracture or unexpected hyperextension(especially in single-radii implants) are not rare. Additional bone-cut, soft-tissue releases or using thicker inserts may cause further instability or pain.\u003c/p\u003e \u003cp\u003eCombining robotics with individulized implants could be one solution. Although extensive literature confirms the efficacy of customized TKA [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan additionalcitationids=\"CR26\" citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], manufacturers remain resistant to modifying femoral sagittal curvature. Most surgical robots are exclusively compatible with proprietary implants, creating integration barriers and specialized instrumentation deficits for customized prostheses. Conversely, the TiRicon system, while analogous to Mako in principle and practicing, accommodates diverse implant systems, enabling seamless integration with customized knee components. As is shown in our protocol, optimized femoral condyles could compensate for flexion-extension mismatch, rather than additional bone-cut or thicker liners; only 27.9% cases in our study adopted exact symmetric inserts, suggesting that minimal imbalance may still exist. Extension gap dedicates insert thickness, with maximum 1mm difference. Kinematics and stability decide slope and congruency of medial insert. In the beginning of our practice, several lateral inserts with 6\u0026deg; slope were adopted, while now we routinely use 3\u0026deg; laterally, as morphology of medial insert was more important than lateral.\u003c/p\u003e \u003cp\u003eThis stepwise methodology, termed \"differential\" TKA, integrates robotic assistance, quantified gap balancing, sequential bone cuts, and customized implants. Borrowed from mathematics, \"differential\" signifies optimizing outcomes through incremental adjustments. To improve clinical outcomes and reduce patient dissatisfaction, the future of TKA requires a pivotal paradigm shift from empirical to analytically driven practice.\u003c/p\u003e \u003cp\u003eLimitations of our study include relatively small sample-size, limited follow-up duration, and non-prospective design. The long-term durability of the locking mechanism for separate tibial inserts warranted further validation. Moreover, the use of different robotic systems (TiRobot vs. Mako) with different implant surface geometry in the comparative groups was another limitation. While both robots are image-based semi-active systems, and all cases used Solver to quantify gap balancing, the confounding factor of different robots could be minimized. Future studies should control for the robotic platform and matched implant designs, employ randomized controlled trials and multi-center studies, to establish higher levels of evidence.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eSynergizing robotic assistance with customized implants showed superior patient satisfaction and functional outcomes compared to robotic-assisted TKA with off-the-shelf implants and and manual TKA. Individualized implant design with more accurate guide of bone-cut, rather than robotics alone, may be the more critical factor in optimizing TKA outcomes.The findings support a paradigm shift in TKA from empirical, alignment-focused methods toward an analytical approach. Future studies should control for the robotic platform with matched implant designs, and employ prospective, multicenter randomized controlled trials, to establish higher-level evidence.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eTKA: total knee arthroplasty\u003c/p\u003e\n\u003cp\u003eRA-C: robotic-assisted customized\u003c/p\u003e\n\u003cp\u003eRA-O: robotic-assisted off-the-shelf\u003c/p\u003e\n\u003cp\u003eHKA: hip-knee-ankle\u003c/p\u003e\n\u003cp\u003eACL: anterior cruciate ligament\u003c/p\u003e\n\u003cp\u003ePCL: posterior cruciate ligament\u003c/p\u003e\n\u003cp\u003eADT: anterior drawer test\u003c/p\u003e\n\u003cp\u003eKOOS: Knee Injury and Osteoarthritis Outcome Score\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFJS: Forgotten Joint Score\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e \u003cp\u003e This research was approved by Ethics Committee of Beijing Jishuitan Hospital, Capital Medical University. Approval number was K2025-538-00. Informed consent to participate was obtained from all of the participants. Our study strictly adhered to the Declaration of Helsinki.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent for publication:\u003c/strong\u003e \u003cp\u003e Written informed consent was obtained from all participants for publication of this research and any accompanying images.\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eCompeting interests:\u003c/h2\u003e \u003cp\u003eWe declare that the authors have no competing interests.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding:\u003c/h2\u003e \u003cp\u003eThis research was supported by Beijing Natural Science Foundation (funding number :L254008)\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eHanlong Zheng wrote the main manuscript text , tables and prepared figure 2 to 4. Zhaolun Wang, Kaiding Wu and Jiajun Zheng performed patient follow-up. Hongyi Shao and Zhaolun Wang provided help for statistical analysis. Yixin Zhou and Ji Zhang andperformed all surgeries in this study, utilizing similar surgical concepts. Yixin Zhou initiated the core concept of \"Analitycal TKA\", provided figure 1 and figure 5, and made substantial revisions for this manuscript. All authors reviewed the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgements:\u003c/h2\u003e \u003cp\u003eNone\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eWe do not have any research data outside the submitted manuscript file. Orignal data could be aquired by e-mailing the corresponding author.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eFlierl MA, Sobh AH, Culp BM, Baker EA, Sporer SM. Evaluation of the Painful Total Knee Arthroplasty. 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BMC Musculoskelet Disord 24. 2023. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s12891-023-07005-5\u003c/span\u003e\u003cspan address=\"10.1186/s12891-023-07005-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHoveidaei AH, Esmaeili S, Ghaseminejad-Raeini A, Pirahesh K, Fallahi MS, et al. Robotic assisted Total Knee Arthroplasty (TKA) is not associated with increased patient satisfaction: a systematic review and meta-analysis. Int Orthop. 2024;48:1771\u0026ndash;84. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00264-024-06206-4\u003c/span\u003e\u003cspan address=\"10.1007/s00264-024-06206-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSteinert AF, Schr\u0026ouml;der L, Sefrin L, Jan\u0026szlig;en B, Arnholdt J, et al. The Impact of Total Knee Replacement with a Customized Cruciate-Retaining Implant Design on Patient-Reported and Functional Outcomes. J Pers Med 12. 2022. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/jpm12020194\u003c/span\u003e\u003cspan address=\"10.3390/jpm12020194\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchroeder L, Pumilia CA, Sarpong NO, Martin G. Patient Satisfaction, Functional Outcomes, and Implant Survivorship in Patients Undergoing Customized Cruciate-Retaining TKA. JBJS Reviews. 2021;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e00077.https://doi.org/10.2106/jbjs.Rvw.20.00074\u003c/span\u003e\u003cspan address=\"00077.10.2106/jbjs.Rvw.20.00074\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. :e20.00074-.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoret CS, Schelker BL, Hirschmann MT. Clinical and Radiological Outcomes after Knee Arthroplasty with Patient-Specific versus Off-the-Shelf Knee Implants: A Systematic Review. J Pers Med 11. 2021. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/jpm11070590\u003c/span\u003e\u003cspan address=\"10.3390/jpm11070590\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoret CS, Hirschmann MT, Vogel N, Arnold MP. Customised, individually made total knee arthroplasty shows promising 1-year clinical and patient reported outcomes. Arch Orthop Trauma Surg. 2021;141:2217\u0026ndash;25. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00402-021-04045-1\u003c/span\u003e\u003cspan address=\"10.1007/s00402-021-04045-1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"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":"journal-of-orthopaedic-surgery-and-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"josr","sideBox":"Learn more about [Journal of Orthopaedic Surgery and Research](http://josr-online.biomedcentral.com)","snPcode":"13018","submissionUrl":"https://submission.nature.com/new-submission/13018/3","title":"Journal of Orthopaedic Surgery and Research","twitterHandle":"@MSKmedBMC","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Robotic-assisted TKA, Patient-specific implants, Customized, Surface geometry, Gap balancing, Patient satisfaction","lastPublishedDoi":"10.21203/rs.3.rs-9065050/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9065050/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eDespite advancements in robotic-assisted total knee arthroplasty (TKA), improvements in patient satisfaction remain limited. This study aimed to compare outcomes and satisfaction among three TKA approaches: robotic-assisted TKA with patient-specific implants, robotic-assisted TKA with off-the-shelf implants, and manual TKA with off-the-shelf implants.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA retrospective cohort study was conducted on 140 knees who underwent TKA between December 2022 and December 2024. Patients were categorized into three groups: RA-C group (n\u0026thinsp;=\u0026thinsp;43), which underwent robotic-assisted TKA with customized implants; RA-O group (n\u0026thinsp;=\u0026thinsp;45), which received robotic-assisted TKA using Mako system with off-the-shelf implants; and Manual group (n\u0026thinsp;=\u0026thinsp;52), which underwent conventional manual TKA using AK A3 GT implants. Customized implants in RA-C group were individually designed based on preoperative CT scans to optimize bony coverage and sagittal curvature, and featured separate medial and lateral tibial inserts. Outcomes included alignment, Knee Injury and Osteoarthritis Outcome Score (KOOS), Forgotten Joint Score (FJS), and a 5-level patient satisfaction scale.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eNo significant differences were found in baseline demographics. In terms of post-operative outcomes, The RA-C group demonstrated significantly higher patient satisfaction than other groups (86.0% very satisfied, 11.6% satisfied and 2.3% neutral, p\u0026thinsp;=\u0026thinsp;0.002). The RA-C group also presented a higher FJS-12 score (78.0\u0026thinsp;\u0026plusmn;\u0026thinsp;14.2) compared to the Manual group (67.4\u0026thinsp;\u0026plusmn;\u0026thinsp;20.2, p\u0026thinsp;=\u0026thinsp;0.012).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eSynergizing robotics with customized implants showed superior satisfaction and functional outcomes compared to robotic-assisted TKA with off-the-shelf implants and manual TKA. Individualized implant design, rather than robotics alone, may be more critical in optimizing TKA outcomes.\u003c/p\u003e","manuscriptTitle":"From Empirical to Analytical: Synergizing Robotic Assistance with Customized Implants for Superior TKA Outcomes","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-07 10:18:32","doi":"10.21203/rs.3.rs-9065050/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-11T09:12:03+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-08T23:03:06+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-07T15:48:30+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"303615357033166097221533394582656070855","date":"2026-04-06T16:27:18+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"73453493211361689557326893606738047779","date":"2026-04-06T15:17:29+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-04T15:45:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"275498426204217767537758007023500827546","date":"2026-04-04T15:41:14+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"26390675150164908277469213559190940938","date":"2026-04-04T00:25:24+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-03T21:06:59+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"270160484096479057919123440811023493491","date":"2026-04-03T09:48:35+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"250723307679633260921336218677480224170","date":"2026-04-03T09:16:38+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"249260076443312273263590324534208518858","date":"2026-04-02T13:28:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"321211521155826751102978767557726721271","date":"2026-04-01T18:56:13+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-01T09:05:53+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-18T07:48:25+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-17T04:48:07+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Orthopaedic Surgery and Research","date":"2026-03-14T08:58:37+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-orthopaedic-surgery-and-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"josr","sideBox":"Learn more about [Journal of Orthopaedic Surgery and Research](http://josr-online.biomedcentral.com)","snPcode":"13018","submissionUrl":"https://submission.nature.com/new-submission/13018/3","title":"Journal of Orthopaedic Surgery and Research","twitterHandle":"@MSKmedBMC","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"b1109767-8751-4bc8-a80b-c29ea4e7c113","owner":[],"postedDate":"April 7th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-11T08:23:51+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-07 10:18:32","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9065050","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9065050","identity":"rs-9065050","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}