The Efficacy of Patellar Denervation on Prognosis and Kneeling Capacity after Unicompartmental Knee Arthroplasty: A Randomized Clinical Trial

The Efficacy of Patellar Denervation on Prognosis and Kneeling Capacity after Unicompartmental Knee Arthroplasty: A Randomized Clinical Trial | 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 The Efficacy of Patellar Denervation on Prognosis and Kneeling Capacity after Unicompartmental Knee Arthroplasty: A Randomized Clinical Trial Ying-Jin Sun, Ning Liu, Long Huang, Xiang-Yang Chen, Shuai Zhao, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4738535/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 05 Oct, 2024 Read the published version in Journal of Orthopaedic Surgery and Research → Version 1 posted 10 You are reading this latest preprint version Abstract Objective The aim of this study was to investigate the effect of patellar denervation (PD) on pain, function and ability to kneel after unicompartmental knee arthroplasty (UKA). Methods Patients with medial knee osteoarthritis who underwent UKA were prospectively selected. Patients were divided into PD and non-PD groups based on whether patellar denervation was performed. Clinical assessment was performed using the Hospital for Special Surgery (HSS) knee score, Kujiala score, visual analogue scale (VAS) and forgotten joint score (FJS-12), as well as postoperative complications were recorded. The patients' postoperative self-perception and actual ability to perform different kneeling positions were assessed in the two groups. Results UKA patients treated with PD achieved better Kujiala scores and FJS-12 scores, reduced anterior knee pain and improved kneeling ability postoperatively, validating the effectiveness of PD in UKA. Perception and actual performance of kneeling remained mismatched in PD patients, but performance during different kneeling activities was generally better than in non-PD patients. Conclusion Patellar denervation can safely and effectively improve patellofemoral joint function, pain and kneeling ability in the early postoperative period after UKA. Clinical Trial Registration: ChiCTR1900025669 unicompartmental knee arthroplasty patellar denervation anterior knee pain kneel Figures Figure 1 Figure 2 Figure 3 Introduction Unicompartmental knee arthroplasty (UKA) is a minimally invasive procedure for the treatment of end-stage osteoarthritis of the medial compartment of the knee that preserves more normal anatomical structures and proprioception[ 1 – 4 ]. Kneeling is an action that Asians often involve in their daily life and religious activities and plays a crucial role in postoperative satisfaction and quality of life[ 5 , 6 ]. Although it has been shown that knee flexion range after UKA did not correlate well with the ability to kneel, kneeling was still a difficult challenge for many early UKA patients[ 7 , 8 ]. More than 50% of patients with knee arthroplasty consider kneeling to be the most important and common activity in their lives, and more than 70% of patients consider kneeling to be the most difficult activity[ 8 ]. Artz et al [ 7 ] found that 32% of UKA patients were still unable to kneel 2 years postoperatively due to pain, and that only 11% of patients were able to kneel easily. Several neurohistological studies have suggested that two nociceptive afferent fibres extending around the patella located in the vastus medialis and vastus lateralis were closely associated with anterior knee pain (AKP) [ 9 , 10 ]. Patellar denervation (PD) is used to reduce AKP by damaging the peripatellar innervation through peripatellar electrocautery [ 11 , 12 ]. The use of PD in total knee arthroplasty has been shown to reduce the risk of postoperative AKP by 32–70%[ 13 – 15 ]. Therefore, more and more orthopaedic surgeons are applying denervation techniques to knee arthroplasty, but reports on its use in UKA are rare[ 11 , 12 , 16 ]. There is a lack of evidence that UKA combined with PD is effective in improving joint function and reducing pain during flexion and kneeling. Therefore, the primary objective of this study was to investigate the effects of PD on pain, joint function, and kneeling ability after UKA The secondary objective was to validate the efficacy and safety of PD for use in UKA. We hypothesised that peripatellar electrocautery denervation would be an effective and safe method to improve joint function, reduce pain, and improve patients' ability to kneel postoperatively. Materials and Methods Patient selection This study was a randomized clinical trial. Based on the selection criteria, we recruited 132 patients who underwent UKA at our hospital between September 2019 and December 2022. This study followed the principles of the Declaration of Helsinki, and all patients were provided preoperative informed consent. This study was approved by the Ethics Committee and has been registered in the Chinese Clinical Trial Registry (ChiCTR1900025669). The inclusion criteria of the study were as follows: ① diagnosis of osteoarthritis of the medial compartment; ② a complete lateral intercompartment gap and anterior cruciate ligament; and ③ the Iwano grade[ 17 ] for patellofemoral joint imaging was stage I-II. ④ Flexion contracture < 15°, knee mobility ≥ 90°, and internal and external valgus deformity < 15°. The exclusion criteria were ① acute osteonecrosis, and inflammatory arthritis such as rheumatoid arthritis, ankylosing spondylitis, gouty arthritis or infectious arthritis; ② a history of knee surgery in the past or during the follow-up; ③ waist, hip or foot pain on the operative side; and ④ incomplete clinical or follow-up data. Sample size calculation The sample size was calculated using G*Power (version 3.1.9.7). The power (1-β) was 80%, the effect size was 0.5, and the two-tailed ɑ was 0.05. The number of samples from at least 53 patients in each group was calculated. We assumed that the loss to follow-up rate was 20%. Therefore, there were 66 patients in each group. Method of randomization Subjects were recruited and randomly assigned by two independent physicians. A randomized grouping scheme was kept in 132 opaque envelopes, which were opened in order of enrollment, and the grouping of patients was determined according to the allocation scheme in the envelopes. The envelopes were not opened until the patient entered the operating room. Patients were categorized into PD group and non-PD group based on whether they received PD. Surgical treatment All surgeries were performed by the same experienced orthopedic team. All patients underwent Oxford mobile-bearing medial UKA (Zimmer Biomet, America) according to the manufacturer's instructions. The patients were placed in the supine position under general anaesthesia, a tourniquet was applied to the thigh, the leg was suspended in a lower limb brace, the hip was flexed at 30° with mild abduction, the calf was naturally lowered, and the knee could be flexed to a minimum of 110°. The joint cavity was opened via a medial parapatellar approach, part of the infrapatellar fat pad was resected, and the osteophytes were removed. According to the principle of flexion-extension balance, tibial plateau and distal femur osteotomies were carried out sequentially, and after installing the trial mould to test the joint movement and stability, the appropriate type of prosthesis was selected, fixed and installed with bone cement. In the PD group, the end of the electrotome was bent 3 mm. In the extended knee position, the medial aspect of the patella was slightly externally turned. Circumferential electrocautery denervation of the patella was performed using an electrocautery knife, especially on the medial-superior and lateral-superior edges of the patella. The depth of electrocautery was 2 to 3 mm. The soft tissues around the knee joint of the two groups were routinely injected with "cocktail" analgesic solution. After the instruments and dressings were counted, one drainage tube was placed, and the wound was closed layer by layer. Postoperative management Standardized protocols were used for all postoperative management. From 12 hours to 2 weeks after the operation, apexaban tablets were taken to prevent thrombosis. The drainage tube was removed within 24 hours after surgery, and the patients were encouraged to walk with the aid of walkers. The patients were instructed to exercise the ankle pump, actively contract the quadriceps femoris and perform straight leg elevation exercises. Patients were asked to follow up in an outpatient clinic at 1, 6 and 12 months after surgery and once a year thereafter. Clinical evaluation Patellar function was evaluated using the Kujiala score[ 18 ], and knee function was evaluated using the Hospital for Special Surgery (HSS) knee score[ 19 ]. The HSS score and Kujala score ranged from 0-100, with higher scores indicating better function. Visual analogue scale (VAS) was used to evaluate the degree of postoperative knee pain[ 20 ]. The degree of postoperative prosthesis self-adaptation was assessed using the Forgotten Joint Score (FJS-12) [ 21 , 22 ] at the last follow-up after surgery, with higher scores indicating a better subjective feeling. Complications that occurred during the perioperative period and follow-up were recorded. Kneeling evaluation At 12 months after surgery, an independent investigator assessed the patients' perceived and actual ability to kneel. Patients were asked in advance if they thought they could kneel at 90° or 120° on the cushion and floor, and their perception of kneeling was assessed according to whether they answered “yes” or “no”. We assessed patients' actual ability to kneel with reference to question 7 of the Oxford Knee Score (score 0–4)[ 23 ]. To simplify the statistical analysis, a score of 0 indicates “impossible”, 1–2 indicates “poor”, and 3–4 indicates “good”. Data Analyses The statistical software used was SPSS 26.0. Continuous variables are expressed as the mean ± standard deviation (SD) and were analysed using Student’s t test. Noncontinuous variables are expressed as numbers and percentages (%) and were analysed using the Chi-square test. Mann-Whitney U test was used to compare the grade data of the two groups. α = 0.05 was used as the test criterion for all parameters, and P < 0.05 was considered to indicate a statistically significant difference. Results There are 58 patients (58 knees) in the PD group and 62 patients (62 knees) in the non-PD group included in the analysis(Fig. 1 ). All baseline characteristics were comparable between the two groups, and there were no significant differences in preoperative demographics, American Society of Anesthesiologists (ASA) grade, Charlson comorbidity index (CCI), patellar morphology, degree of patellofemoral joint degeneration and clinical scores were not significantly different (Table 1 ). Table 1 Demographic data PD (n = 58) Non-PD (n = 62) P- Value Age (y) 62.3 ± 7.2 63.4 ± 7.3 0.413 Sex (%) 0.220 Man 23 (39.7) 18 (29.0) Woman 35 (60.3) 44 (71.0) BMI (kg/m²) 25.8 ± 3.4 26.2 ± 2.7 0.401 CCI (%) 0.219 Grade I 36 (62.1) 45 (72.6) Grade II 22 (37.9) 17 (27.4) ASA grade (%) 0.200 Grade I 28 (48.3) 40 (64.5) Grade II 22 (37.9) 18 (29.0) Grade III 8 (13.8) 4 (6.5) Wiberg classification (%) 0.276 Type I 10 (17.2) 18 (29.0) Type II 35 (60.3) 30 (48.4) Type III 13 (22.4) 14 (22.6) Iwano stage (%) 0.378 Stage I 40 (69.0) 38 (61.3) Stage II 18 (31.0) 24 (38.7) Preoperative HSS score 52.6 ± 6.8 53.8 ± 6.1 0.321 Preoperative Kujala score 46.7 ± 5.8 48.5 ± 6.0 0.110 BMI, body mass index; CCI, Charlson comorbidity index; ASA, American Society of Anesthesiologists Clinical outcomes The clinical outcomes showed statistically significant differences in postoperative Kujala scores, VAS and FJS-12 scores between the two groups; there was no statistically significant difference in postoperative HSS scores between the two groups (Table 2 ). Table 2 Comparison of postoperative clinical outcomes between the two groups PD (n = 58) Non-PD (n = 62) P -Value HSS score At 6 months 88.2 ± 4.2 86.8 ± 4.8 0.102 At 12 months 90.3 ± 4.2 89.3 ± 4.3 0.171 Kujala score At 6 months 80.5 ± 4.2 76.7 ± 5.2 < 0.001 At 12 months 83.8 ± 3.9 81.5 ± 4.4 0.004 VAS At 6 months 1.3 ± 0.6 1.7 ± 0.8 0.007 At 12 months 1.2 ± 0.4 1.4 ± 0.6 0.027 FJS-12 73.8 ± 6.5 70.4 ± 5.8 0.003 Cushion Kneeling perception (Yes / No) 34/24 32/30 0.441 Floor Kneeling perception (Yes / No) 26/32 25/37 0.618 HSS, the hospital for special surgery; FJS-12, the Forgotten Joint Score. Bold values indicate statistically significant values ( P < 0.05). Kneeling outcomes There was statistically significant difference in the actual ability to kneel in the postoperative period between the two groups (Table 3 ). The highest percentage of “good” actual kneeling ability was “90° kneeling on the cushion in the PD group (55.2%) ” and the lowest percentage of “good” actual ability was “120° kneeling on the floor in the non-PD group (16.1%)”. The highest percentage of actual inability to kneel was “on the floor in the non-PD group (24.2%)”, and the lowest percentage was “on the cushion in the PD group (6.9%)”. Table 3 Comparison of postoperative kneeling scores for Question 7 of the Oxford Knee Score Impossible Poor Good P -Value 90° Kneeling (Cushion) 0.029 PD 4 (6.9) 22 (37.9) 32 (55.2) Non-PD 10 (16.1) 29 (46.8) 23 (37.1) 120° Kneeling (Cushion) 0.018 PD 4 (6.9) 25 (43.1) 29 (50.0) Non-PD 10 (16.1) 11 33 (53.2) 19 (30.6) 90° Kneeling (Floor) 0.038 PD 7 (12.1) 31 (53.4) 20 (34.5) Non-PD 15 (24.2) 34 (54.8) 13 (21.0) 120° Kneeling (Floor) 0.031 PD 7 (12.1) 34 (58.6) 17 (29.3) Non-PD 15 (24.2) 37 (59.6) 10 (16.1) Bold values indicate statistically significant values ( P < 0.05). There was significant difference between the perceived and actual performance of the two groups (Fig. 2 , Fig. 3 ). The highest concordance between patients' actual kneeling performance being “good” and perceiving that they could kneel was “120° kneeling on the cushion in the PD group (89.7%) ”, and the worst concordance was “90° kneeling on the floor in the non-PD group (69.2%) ”. The highest concordance between patients' actual inability to kneel and their perceived inability to kneel was "kneeling on the cushion in the PD group (100%)", and the worst concordance was "kneeling cushion in the non-PD group (80%)". Postoperative complications During the perioperative period, the intervention group and conventional group had 3 cases of lower extremity vein thrombosis (1 and 2, respectively), 1 case of hematoma (0 and 1, respectively) and 3 cases of poorly healed skin incisions (1 and 2, respectively). The patients were cured after symptomatic treatment, and none of them underwent secondary surgical revision. The incidence of postoperative complications was 5.2% (3/58) in the PD group and 6.5% (4/62) in the non-PD group. The difference between the two groups was not statistically significant ( P = 0.537). There were no postoperative complications, such as infection, fracture, patellar necrosis, or implant loosening, in either group during the follow-up period. Discussion The findings in this study were consistent with the hypothesis. UKA patients treated with PD achieved better Kujiala scores and FJS-12 scores, reduced anterior knee pain and improved kneeling ability postoperatively, validating the effectiveness of PD in UKA. Perception and actual performance of kneeling remained mismatched in PD patients, but performance during different kneeling activities was generally better than in non-PD patients. No postoperative complications due to peripatellar electrocautery were found in UKA patients who underwent PD treatment, indicating the safety of PD in UKA. PD can effectively reduce postoperative AKP, but the pathogenesis of postoperative AKP has not been fully elucidated, and it is generally believed that substance-p nerve fibres in the peripatellar soft tissue are the main cause. Substance P, an nociceptive neurotransmitter found in afferent nerve fibres, is predominantly found in the the patellar retinaculum, fat pad, periosteum, and cartilage affected by degenerative diseases[ 9 , 24 ]. Therefore, pain receptor desensitization through peripatellar electrocautery can reduce pain transmission. In addition, peripatellar soft tissue traction or bony structure compression may cause nerve fibre edema and degeneration, as well as intraoperative traction and suturing may easily produce peripheral neuralgia, increasing the risk of postoperative pain. The denervation technique can partially terminate the potential pain pathway and reduce the occurrence of pain. The effectiveness of PD is currently controversial. Our study revealed that patients who underwent PD had better patellar scores, greater joint forgetting and less pain. However, some studies have suggested that these improvements may not be durable. However, some studies have suggested that these improvements may not be long-lasting. A meta-analysis by Yuan et al [ 15 ] showed that the effective effect of PD was limited to 12 months postoperatively, but a meta-analysis by Duan et al [ 25 ] demonstrated that the effect of PD can extend beyond 12 months. As severe patellofemoral joint degeneration (PFJD) is widely considered a contraindication to UKA, all the patients included in this study did not have severe PFJD. However, a prospective study by Suwankomonkul et al [ 12 ] showed that UKA patients with severe PFJD who received PD also had favourable outcomes in the short term. It is worth noting that Pongcharoen et al [ 26 ] conducted a prospective comparison of patients with severe and non-severe PFJD treated with UKA, and the results showed that patients with severe PFJD had poorer knee joint scores. In addition, Hamilton et al [ 27 ] reported up to 15 years of follow-up in UKA patients that severe PFJD may have a negative impact on descending stairs. Considering the unsustainable effectiveness of PD and the long-term adverse outcomes of severe PFJD, UKA in combination with PD is not recommended as the preferred option for patients with bicompartmental lesions. PD patients showed significant improvement in kneeling ability after surgery. The results also further confirm the findings of the Artz et al [ 7 ] study that there is a correlation between kneeling ability, pain and function. The causes of kneeling difficulties are multifaceted; in addition to pain and function, numbness, fear of injury to the prosthesis, comorbidities and third-party recommendations can all contribute to limitations in kneeling [ 28 – 31 ]. Many healthcare professionals advise patients not to kneel due to concerns about the safety of kneeling, but there is no clinical evidence of an association between kneeling and prosthesis loosening. This and other studies have found discrepancies between patients' self-perceived ability to kneel and their actual ability to observe [ 32 , 33 ]. Although some patients may perceive an inability to kneel, many patients actually have the potential to kneel after appropriate rehabilitation training and instruction[ 28 , 30 , 34 ]. Therefore, while PD improves the ability to kneel by improving the patient's function and reducing AKP, there is still a need for acquired help to build confidence and overcome kneeling difficulties through a comprehensive rehabilitation programme, individualized education and advice, and effective physiotherapy. In this study, the application of PD in UKA was not found to increase the occurrence of related complications. However, during electrocautery denervation in the peripatellar region, it may cause damage to the nutrient vessels around the patella, increasing the risk of patellar necrosis and fracture [ 10 , 35 ]. Therefore, the operator should be familiar with the distribution of the peripatellar nerves and master the range and depth of electrocautery. Before peripatellar electrocautery, we bent the metal tip of the electrotome tip by 3 mm. This not only prevents the patella from completely turning over, but also controls the depth of electrocautery and avoids damage caused by nerve regeneration and excessive electrocautery. This study inevitably has several limitations. First, the short follow-up period of this study did not allow for observation of long-term outcomes or complications. Second, this study transformed the five-categorical variables into three-categorical variables in assessing the ability to kneel. Although the multicategorical transformation can simplify model building and interpretation, it may cause limitations in the reliability and interpretability of the results. In addition, this study was evaluated only through four simple kneeling activities and lacked multidimensional tests of kneeling ability. Therefore, there is still a need for long-term prospective studies to validate PD in UKA and more comprehensive tests to assess kneeling ability in the future. Conclusion Patellar denervation can safely and effectively improve patellofemoral joint function, pain and kneeling ability in the early postoperative period after UKA. Abbreviations UKA unicompartmental knee arthroplasty PD patellar denervation HSS Hospital for Special Surgery VAS visual analogue scale FJS-12 forgotten joint score AKP anterior knee pain PFJD patellofemoral joint degeneration ASA American Society of Anesthesiologists CCI Charlson comorbidity index Declarations Ethics approval and consent to participate This study has been approved by the Ethics Committee of Xuzhou Medical University Affiliated Hospital. Consent for publication All eligible participants signed an informed consent form prior to surgery. Competing interests The authors declare that they have no competing interests. Funding This study was funded by the Youth medical science and technology innovation project of Xuzhou Health Commission (XWKYHT20210577) and Affiliated Hospital of Xuzhou Medical College (2020104734). Author Contribution SYJ analyzed the data and wrote the manuscript. HL and LN was responsible for data collection and collation. CXY provided supervision and guidance on the content of research topics. FS and ZS made significant contributions to the conception and design of the study, and critically revised the manuscript. All authors read and approved the final manuscript. Data Availability The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. References Jenny J-Y. Minimally invasive unicompartmental knee arthroplasty. Eur J Orthop Surg Traumatol 2018;28:793–7. https://doi.org/10.1007/s00590-017-2107-5. Ge J, Hernigou P, Guo W, Zhang N, Liu C, Zhang Q. Minimally invasive small incision surgical technique for unicompartmental knee arthroplasty. Int Orthop 2023;47:2717–25. https://doi.org/10.1007/s00264-023-05908-5. Al-Dadah O, Hing C. Unicompartmental Knee Arthroplasty: General trends of clinical practice. Knee 2023;41:A1–2. https://doi.org/10.1016/j.knee.2023.03.013. Knifsund J, Niinimaki T, Nurmi H, Toom A, Keemu H, Laaksonen I, et al. Functional results of total-knee arthroplasty versus medial unicompartmental arthroplasty: two-year results of a randomised, assessor-blinded multicentre trial. BMJ Open 2021;11:e046731. https://doi.org/10.1136/bmjopen-2020-046731. Barker KL, Hannink E, Pemberton S, Jenkins C. Knee Arthroplasty Patients Predicted Versus Actual Recovery: What Are Their Expectations About Time of Recovery After Surgery and How Long Before They Can Do the Tasks They Want to Do? Arch Phys Med Rehabil 2018;99:2230–7. https://doi.org/10.1016/j.apmr.2018.03.022. Scott CEH, Bugler KE, Clement ND, MacDonald D, Howie CR, Biant LC. Patient expectations of arthroplasty of the hip and knee. J Bone Joint Surg Br 2012;94:974–81. https://doi.org/10.1302/0301-620X.94B7.28219. Artz NJ, Hassaballa MA, Robinson JR, Newman JH, Porteous AJ, Murray JRD. Patient Reported Kneeling Ability in Fixed and Mobile Bearing Knee Arthroplasty. J Arthroplasty 2015;30:2159–63. https://doi.org/10.1016/j.arth.2015.06.063. Weiss JM, Noble PC, Conditt MA, Kohl HW, Roberts S, Cook KF, et al. What functional activities are important to patients with knee replacements? Clin Orthop Relat Res 2002:172–88. https://doi.org/10.1097/00003086-200211000-00030. Wojtys EM, Beaman DN, Glover RA, Janda D. Innervation of the human knee joint by substance-P fibers. Arthroscopy 1990;6:254–63. https://doi.org/10.1016/0749-8063(90)90054-h. Maralcan G, Kuru I, Issi S, Esmer AF, Tekdemir I, Evcik D. The innervation of patella: anatomical and clinical study. Surg Radiol Anat 2005;27:331–5. https://doi.org/10.1007/s00276-005-0334-7. Budhiparama NC, Hidayat H, Novito K, Utomo DN, Lumban-Gaol I, Nelissen RGHH. Does Circumferential Patellar Denervation Result in Decreased Knee Pain and Improved Patient-reported Outcomes in Patients Undergoing Nonresurfaced, Simultaneous Bilateral TKA? Clin Orthop Relat Res 2020;478:2020–33. https://doi.org/10.1097/CORR.0000000000001035. Suwankomonkul P, Arirachakaran A, Kongtharvonskul J. Short-term improvement of patellofemoral pain in medial unicompartmental knee arthroplasty with patellar denervation: a prospective comparative study. Musculoskelet Surg 2022;106:75–82. https://doi.org/10.1007/s12306-020-00675-7. Alomran A. Effect of patellar denervation on mid-term results after non-resurfaced total knee arthroplasty. A randomised, controlled trial. Acta Orthop Belg 2015;81:609–13. van Jonbergen H-PW, Reuver JM, Mutsaerts EL, Poolman RW. Determinants of anterior knee pain following total knee replacement: a systematic review. Knee Surg Sports Traumatol Arthrosc 2014;22:478–99. https://doi.org/10.1007/s00167-012-2294-x. Yuan M-C, Ding Z-C, Ling T-X, Zhou Z. Patellar Denervation with Electrocautery Reduces Anterior Knee Pain within 1 Year after Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials. Orthop Surg 2021;13:14–27. https://doi.org/10.1111/os.12735. Xie X, Pei F, Huang Z, Tan Z, Yang Z, Kang P. Does patellar denervation reduce post-operative anterior knee pain after total knee arthroplasty? Knee Surg Sports Traumatol Arthrosc 2015;23:1808–15. https://doi.org/10.1007/s00167-015-3566-z. Iwano T, Kurosawa H, Tokuyama H, Hoshikawa Y. Roentgenographic and clinical findings of patellofemoral osteoarthrosis. With special reference to its relationship to femorotibial osteoarthrosis and etiologic factors. Clin Orthop Relat Res 1990:190–7. Kujala UM, Jaakkola LH, Koskinen SK, Taimela S, Hurme M, Nelimarkka O. Scoring of patellofemoral disorders. Arthroscopy 1993;9:159–63. https://doi.org/10.1016/s0749-8063(05)80366-4. Ranawat CS, Insall J, Shine J. Duo-condylar knee arthroplasty: hospital for special surgery design. Clin Orthop Relat Res 1976:76–82. Hawker GA, Mian S, Kendzerska T, French M. Measures of adult pain: Visual Analog Scale for Pain (VAS Pain), Numeric Rating Scale for Pain (NRS Pain), McGill Pain Questionnaire (MPQ), Short-Form McGill Pain Questionnaire (SF-MPQ), Chronic Pain Grade Scale (CPGS), Short Form-36 Bodily Pain Scale (SF-36 BPS), and Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP). Arthritis Care Res (Hoboken) 2011;63 Suppl 11:S240-252. https://doi.org/10.1002/acr.20543. Thienpont E, Opsomer G, Koninckx A, Houssiau F. Joint awareness in different types of knee arthroplasty evaluated with the Forgotten Joint score. J Arthroplasty 2014;29:48–51. https://doi.org/10.1016/j.arth.2013.04.024. Behrend H, Giesinger K, Giesinger JM, Kuster MS. The “forgotten joint” as the ultimate goal in joint arthroplasty: validation of a new patient-reported outcome measure. J Arthroplasty 2012;27:430-436.e1. https://doi.org/10.1016/j.arth.2011.06.035. Dawson J, Fitzpatrick R, Murray D, Carr A. Questionnaire on the perceptions of patients about total knee replacement. J Bone Joint Surg Br 1998;80:63–9. https://doi.org/10.1302/0301-620x.80b1.7859. Witoński D, Wagrowska-Danielewicz M. Distribution of substance-P nerve fibers in the knee joint in patients with anterior knee pain syndrome. A preliminary report. Knee Surg Sports Traumatol Arthrosc 1999;7:177–83. https://doi.org/10.1007/s001670050144. Duan G, Liu C, Lin W, Shao J, Fu K, Niu Y, et al. Different Factors Conduct Anterior Knee Pain Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis. J Arthroplasty 2018;33:1962-1971.e3. https://doi.org/10.1016/j.arth.2017.12.024. Pongcharoen B, Reutiwarangkoon C. The comparison of anterior knee pain in severe and non severe arthritis of the lateral facet of the patella following a mobile bearing unicompartmental knee arthroplasty. Springerplus 2016;5:202. https://doi.org/10.1186/s40064-016-1914-1. Hamilton TW, Pandit HG, Maurer DG, Ostlere SJ, Jenkins C, Mellon SJ, et al. Anterior knee pain and evidence of osteoarthritis of the patellofemoral joint should not be considered contraindications to mobile-bearing unicompartmental knee arthroplasty: a 15-year follow-up. Bone Joint J 2017;99-B:632–9. https://doi.org/10.1302/0301-620X.99B5.BJJ-2016-0695.R2. Hassaballa MA, Porteous AJ, Newman JH. Observed kneeling ability after total, unicompartmental and patellofemoral knee arthroplasty: perception versus reality. Knee Surg Sports Traumatol Arthrosc 2004;12:136–9. https://doi.org/10.1007/s00167-003-0376-5. Fletcher D, Moore AJ, Blom AW, Wylde V. An exploratory study of the long-term impact of difficulty kneeling after total knee replacement. Disabil Rehabil 2019;41:820–5. https://doi.org/10.1080/09638288.2017.1410860. White L, Stockwell T, Hartnell N, Hennessy M, Mullan J. Factors preventing kneeling in a group of pre-educated patients post total knee arthroplasty. J Orthop Traumatol 2016;17:333–8. https://doi.org/10.1007/s10195-016-0411-1. MacDonald B, Kurdin A, Somerville L, Ross D, MacDonald S, Lanting B. The Effect of Sensory Deficit After Total Knee Arthroplasty on Patient Satisfaction and Kneeling Ability. Arthroplast Today 2021;7:264-267.e2. https://doi.org/10.1016/j.artd.2020.11.020. Narkbunnam R, Rojjananukulpong K, Ruangsomboon P, Chareancholvanich K, Pornrattanamaneewong C. The association between perception of patients and their actual ability to do floor activities after mobile-bearing unicompartmental knee arthroplasty: A prospective, cross-sectional study. Jt Dis Relat Surg 2023;34:245–52. https://doi.org/10.52312/jdrs.2023.877. Schai PA, Gibbon AJ, Scott RD. Kneeling ability after total knee arthroplasty. Perception and reality. Clin Orthop Relat Res 1999:195–200. Jenkins C, Barker KL, Pandit H, Dodd CAF, Murray DW. After partial knee replacement, patients can kneel, but they need to be taught to do so: a single-blind randomized controlled trial. Phys Ther 2008;88:1012–21. https://doi.org/10.2522/ptj.20070374. Russell RD, Huo MH, Jones RE. Avoiding patellar complications in total knee replacement. Bone Joint J 2014;96-B:84–6. https://doi.org/10.1302/0301-620X.96B11.34305. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 05 Oct, 2024 Read the published version in Journal of Orthopaedic Surgery and Research → Version 1 posted Editorial decision: Revision requested 22 Jul, 2024 Reviews received at journal 21 Jul, 2024 Reviews received at journal 18 Jul, 2024 Reviewers agreed at journal 18 Jul, 2024 Reviewers agreed at journal 16 Jul, 2024 Reviewers agreed at journal 16 Jul, 2024 Reviewers invited by journal 16 Jul, 2024 Editor assigned by journal 16 Jul, 2024 Submission checks completed at journal 16 Jul, 2024 First submitted to journal 14 Jul, 2024 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-4738535","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":329971780,"identity":"62e92900-31ba-4c02-b3b4-edf52aedc7e4","order_by":0,"name":"Ying-Jin Sun","email":"","orcid":"","institution":"Affiliated Hospital of Xuzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Ying-Jin","middleName":"","lastName":"Sun","suffix":""},{"id":329971781,"identity":"6c124dd0-2dd0-4c23-b612-ebc33d93d56f","order_by":1,"name":"Ning Liu","email":"","orcid":"","institution":"Affiliated Hospital of Xuzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Ning","middleName":"","lastName":"Liu","suffix":""},{"id":329971782,"identity":"7b8719ab-1fe8-4dd5-81ed-0175d074a7c1","order_by":2,"name":"Long Huang","email":"","orcid":"","institution":"Affiliated Hospital of Xuzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Long","middleName":"","lastName":"Huang","suffix":""},{"id":329971783,"identity":"cbcf2054-8871-48ab-8d19-57d81f2bf207","order_by":3,"name":"Xiang-Yang Chen","email":"","orcid":"","institution":"Affiliated Hospital of Xuzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Xiang-Yang","middleName":"","lastName":"Chen","suffix":""},{"id":329971784,"identity":"a96a2e74-81c9-4281-a33c-8d529dd81f9a","order_by":4,"name":"Shuai Zhao","email":"","orcid":"","institution":"Affiliated Hospital of Xuzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Shuai","middleName":"","lastName":"Zhao","suffix":""},{"id":329971785,"identity":"d5987b81-6349-4b3b-954d-673d4b2c16c2","order_by":5,"name":"Shuo Feng","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAw0lEQVRIie3QoQvCQBTH8TseXHpzdUODf8KDgenAP8RyljW7YeFA0CIs7z8xDh8sDfYPGJbMk1WDMxrkzma4T37f8H5CBMFfkr3YPjXGANx7JkDiYfNFelI5eSeysldNHS4Tr4A6hjG61JgxChKF3jiT1LKaR+0NVxzVvWjynXUlsSwbQHWfkpkhadmdKAAYUTFmB6TEK4kViLQ6MhL4JukZVDK0OSY8jWx8fnkvNpi9Xsclcz8U2p18Mr+dB0EQBN+8AFyROsgjsLkQAAAAAElFTkSuQmCC","orcid":"","institution":"Affiliated Hospital of Xuzhou Medical College","correspondingAuthor":true,"prefix":"","firstName":"Shuo","middleName":"","lastName":"Feng","suffix":""}],"badges":[],"createdAt":"2024-07-14 13:14:25","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4738535/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4738535/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s13018-024-05015-0","type":"published","date":"2024-10-05T15:57:08+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":62646888,"identity":"10541997-0f84-4385-8e86-4935403b24d4","added_by":"auto","created_at":"2024-08-16 21:20:34","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":57565,"visible":true,"origin":"","legend":"\u003cp\u003eCONSORT flow diagram showing the enrollment of the patients, the allocation of treatment, and the completion of the study.\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4738535/v1/7f6de1f20d205338b603b1f8.jpg"},{"id":62646886,"identity":"5a8b4d93-788e-4838-a2ed-cd42ad67eb9b","added_by":"auto","created_at":"2024-08-16 21:20:34","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":49628,"visible":true,"origin":"","legend":"\u003cp\u003eMatching self perception and actual ability of PD patients in four kneeling positions.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4738535/v1/2b44c8db535b9ad6da56af31.jpg"},{"id":62646889,"identity":"bdc8b7b1-5a88-429c-9db1-ce739f1e1e87","added_by":"auto","created_at":"2024-08-16 21:20:34","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":49899,"visible":true,"origin":"","legend":"\u003cp\u003eMatching self perception and actual ability of non-PD patients in four kneeling positions.\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4738535/v1/50ea5f3a93e6afb146efee46.jpg"},{"id":66096942,"identity":"dcace02e-2462-4ac5-9cbf-d8c0ca1322ab","added_by":"auto","created_at":"2024-10-07 16:12:01","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":721410,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4738535/v1/837c5fb3-e805-406a-8014-2429eb2e0bc6.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Efficacy of Patellar Denervation on Prognosis and Kneeling Capacity after Unicompartmental Knee Arthroplasty: A Randomized Clinical Trial","fulltext":[{"header":"Introduction","content":"\u003cp\u003eUnicompartmental knee arthroplasty (UKA) is a minimally invasive procedure for the treatment of end-stage osteoarthritis of the medial compartment of the knee that preserves more normal anatomical structures and proprioception[\u003cspan additionalcitationids=\"CR2 CR3\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Kneeling is an action that Asians often involve in their daily life and religious activities and plays a crucial role in postoperative satisfaction and quality of life[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Although it has been shown that knee flexion range after UKA did not correlate well with the ability to kneel, kneeling was still a difficult challenge for many early UKA patients[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. More than 50% of patients with knee arthroplasty consider kneeling to be the most important and common activity in their lives, and more than 70% of patients consider kneeling to be the most difficult activity[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Artz et al [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] found that 32% of UKA patients were still unable to kneel 2 years postoperatively due to pain, and that only 11% of patients were able to kneel easily.\u003c/p\u003e \u003cp\u003eSeveral neurohistological studies have suggested that two nociceptive afferent fibres extending around the patella located in the vastus medialis and vastus lateralis were closely associated with anterior knee pain (AKP) [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Patellar denervation (PD) is used to reduce AKP by damaging the peripatellar innervation through peripatellar electrocautery [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The use of PD in total knee arthroplasty has been shown to reduce the risk of postoperative AKP by 32\u0026ndash;70%[\u003cspan additionalcitationids=\"CR14\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Therefore, more and more orthopaedic surgeons are applying denervation techniques to knee arthroplasty, but reports on its use in UKA are rare[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThere is a lack of evidence that UKA combined with PD is effective in improving joint function and reducing pain during flexion and kneeling. Therefore, the primary objective of this study was to investigate the effects of PD on pain, joint function, and kneeling ability after UKA The secondary objective was to validate the efficacy and safety of PD for use in UKA. We hypothesised that peripatellar electrocautery denervation would be an effective and safe method to improve joint function, reduce pain, and improve patients' ability to kneel postoperatively.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePatient selection\u003c/h2\u003e \u003cp\u003eThis study was a randomized clinical trial. Based on the selection criteria, we recruited 132 patients who underwent UKA at our hospital between September 2019 and December 2022. This study followed the principles of the Declaration of Helsinki, and all patients were provided preoperative informed consent. This study was approved by the Ethics Committee and has been registered in the Chinese Clinical Trial Registry (ChiCTR1900025669).\u003c/p\u003e \u003cp\u003eThe inclusion criteria of the study were as follows: ① diagnosis of osteoarthritis of the medial compartment; ② a complete lateral intercompartment gap and anterior cruciate ligament; and ③ the Iwano grade[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] for patellofemoral joint imaging was stage I-II. ④ Flexion contracture\u0026thinsp;\u0026lt;\u0026thinsp;15\u0026deg;, knee mobility\u0026thinsp;\u0026ge;\u0026thinsp;90\u0026deg;, and internal and external valgus deformity\u0026thinsp;\u0026lt;\u0026thinsp;15\u0026deg;. The exclusion criteria were ① acute osteonecrosis, and inflammatory arthritis such as rheumatoid arthritis, ankylosing spondylitis, gouty arthritis or infectious arthritis; ② a history of knee surgery in the past or during the follow-up; ③ waist, hip or foot pain on the operative side; and ④ incomplete clinical or follow-up data.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSample size calculation\u003c/h3\u003e\n\u003cp\u003eThe sample size was calculated using G*Power (version 3.1.9.7). The power (1-β) was 80%, the effect size was 0.5, and the two-tailed ɑ was 0.05. The number of samples from at least 53 patients in each group was calculated. We assumed that the loss to follow-up rate was 20%. Therefore, there were 66 patients in each group.\u003c/p\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eMethod of randomization\u003c/h2\u003e \u003cp\u003eSubjects were recruited and randomly assigned by two independent physicians. A randomized grouping scheme was kept in 132 opaque envelopes, which were opened in order of enrollment, and the grouping of patients was determined according to the allocation scheme in the envelopes. The envelopes were not opened until the patient entered the operating room. Patients were categorized into PD group and non-PD group based on whether they received PD.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eSurgical treatment\u003c/h2\u003e \u003cp\u003eAll surgeries were performed by the same experienced orthopedic team. All patients underwent Oxford mobile-bearing medial UKA (Zimmer Biomet, America) according to the manufacturer's instructions. The patients were placed in the supine position under general anaesthesia, a tourniquet was applied to the thigh, the leg was suspended in a lower limb brace, the hip was flexed at 30\u0026deg; with mild abduction, the calf was naturally lowered, and the knee could be flexed to a minimum of 110\u0026deg;. The joint cavity was opened via a medial parapatellar approach, part of the infrapatellar fat pad was resected, and the osteophytes were removed. According to the principle of flexion-extension balance, tibial plateau and distal femur osteotomies were carried out sequentially, and after installing the trial mould to test the joint movement and stability, the appropriate type of prosthesis was selected, fixed and installed with bone cement. In the PD group, the end of the electrotome was bent 3 mm. In the extended knee position, the medial aspect of the patella was slightly externally turned. Circumferential electrocautery denervation of the patella was performed using an electrocautery knife, especially on the medial-superior and lateral-superior edges of the patella. The depth of electrocautery was 2 to 3 mm. The soft tissues around the knee joint of the two groups were routinely injected with \"cocktail\" analgesic solution. After the instruments and dressings were counted, one drainage tube was placed, and the wound was closed layer by layer.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003ePostoperative management\u003c/h2\u003e \u003cp\u003eStandardized protocols were used for all postoperative management. From 12 hours to 2 weeks after the operation, apexaban tablets were taken to prevent thrombosis. The drainage tube was removed within 24 hours after surgery, and the patients were encouraged to walk with the aid of walkers. The patients were instructed to exercise the ankle pump, actively contract the quadriceps femoris and perform straight leg elevation exercises. Patients were asked to follow up in an outpatient clinic at 1, 6 and 12 months after surgery and once a year thereafter.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eClinical evaluation\u003c/h2\u003e \u003cp\u003ePatellar function was evaluated using the Kujiala score[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], and knee function was evaluated using the Hospital for Special Surgery (HSS) knee score[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The HSS score and Kujala score ranged from 0-100, with higher scores indicating better function. Visual analogue scale (VAS) was used to evaluate the degree of postoperative knee pain[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. The degree of postoperative prosthesis self-adaptation was assessed using the Forgotten Joint Score (FJS-12) [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] at the last follow-up after surgery, with higher scores indicating a better subjective feeling. Complications that occurred during the perioperative period and follow-up were recorded.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eKneeling evaluation\u003c/h2\u003e \u003cp\u003eAt 12 months after surgery, an independent investigator assessed the patients' perceived and actual ability to kneel. Patients were asked in advance if they thought they could kneel at 90\u0026deg; or 120\u0026deg; on the cushion and floor, and their perception of kneeling was assessed according to whether they answered \u0026ldquo;yes\u0026rdquo; or \u0026ldquo;no\u0026rdquo;. We assessed patients' actual ability to kneel with reference to question 7 of the Oxford Knee Score (score 0\u0026ndash;4)[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. To simplify the statistical analysis, a score of 0 indicates \u0026ldquo;impossible\u0026rdquo;, 1\u0026ndash;2 indicates \u0026ldquo;poor\u0026rdquo;, and 3\u0026ndash;4 indicates \u0026ldquo;good\u0026rdquo;.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eData Analyses\u003c/h2\u003e \u003cp\u003eThe statistical software used was SPSS 26.0. Continuous variables are expressed as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD) and were analysed using Student\u0026rsquo;s t test. Noncontinuous variables are expressed as numbers and percentages (%) and were analysed using the Chi-square test. Mann-Whitney U test was used to compare the grade data of the two groups. \u003cem\u003eα\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.05 was used as the test criterion for all parameters, and \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered to indicate a statistically significant difference.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eThere are 58 patients (58 knees) in the PD group and 62 patients (62 knees) in the non-PD group included in the analysis(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). All baseline characteristics were comparable between the two groups, and there were no significant differences in preoperative demographics, American Society of Anesthesiologists (ASA) grade, Charlson comorbidity index (CCI), patellar morphology, degree of patellofemoral joint degeneration and clinical scores were not significantly different (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDemographic data\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePD (n\u0026thinsp;=\u0026thinsp;58)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNon-PD (n\u0026thinsp;=\u0026thinsp;62)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP-\u003c/em\u003eValue\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (y)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e62.3\u0026thinsp;\u0026plusmn;\u0026thinsp;7.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e63.4\u0026thinsp;\u0026plusmn;\u0026thinsp;7.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.413\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.220\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMan\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23 (39.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18 (29.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWoman\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e35 (60.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e44 (71.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI (kg/m\u0026sup2;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25.8\u0026thinsp;\u0026plusmn;\u0026thinsp;3.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26.2\u0026thinsp;\u0026plusmn;\u0026thinsp;2.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.401\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCCI (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.219\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade I\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36 (62.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e45 (72.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade II\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22 (37.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17 (27.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eASA grade (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.200\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade I\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28 (48.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40 (64.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade II\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22 (37.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18 (29.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrade III\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (13.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (6.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWiberg classification (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.276\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType I\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 (17.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18 (29.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType II\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e35 (60.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30 (48.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType III\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13 (22.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14 (22.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIwano stage (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.378\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage I\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40 (69.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38 (61.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStage II\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18 (31.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24 (38.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePreoperative HSS score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e52.6\u0026thinsp;\u0026plusmn;\u0026thinsp;6.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e53.8\u0026thinsp;\u0026plusmn;\u0026thinsp;6.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.321\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePreoperative Kujala score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e46.7\u0026thinsp;\u0026plusmn;\u0026thinsp;5.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e48.5\u0026thinsp;\u0026plusmn;\u0026thinsp;6.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.110\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eBMI, body mass index; CCI, Charlson comorbidity index; ASA, American Society of Anesthesiologists\u003c/p\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eClinical outcomes\u003c/h2\u003e \u003cp\u003eThe clinical outcomes showed statistically significant differences in postoperative Kujala scores, VAS and FJS-12 scores between the two groups; there was no statistically significant difference in postoperative HSS scores between the two groups (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of postoperative clinical outcomes between the two groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePD (n\u0026thinsp;=\u0026thinsp;58)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNon-PD (n\u0026thinsp;=\u0026thinsp;62)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e-Value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHSS score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAt 6 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e88.2\u0026thinsp;\u0026plusmn;\u0026thinsp;4.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e86.8\u0026thinsp;\u0026plusmn;\u0026thinsp;4.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.102\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAt 12 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e90.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e89.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.171\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eKujala score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAt 6 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e80.5\u0026thinsp;\u0026plusmn;\u0026thinsp;4.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e76.7\u0026thinsp;\u0026plusmn;\u0026thinsp;5.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAt 12 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e83.8\u0026thinsp;\u0026plusmn;\u0026thinsp;3.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e81.5\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.004\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVAS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAt 6 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.007\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAt 12 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.027\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFJS-12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e73.8\u0026thinsp;\u0026plusmn;\u0026thinsp;6.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e70.4\u0026thinsp;\u0026plusmn;\u0026thinsp;5.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e0.003\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCushion Kneeling perception (Yes / No)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e34/24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32/30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.441\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFloor Kneeling perception (Yes / No)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26/32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25/37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.618\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eHSS, the hospital for special surgery; FJS-12, the Forgotten Joint Score. Bold values indicate statistically significant values (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eKneeling outcomes\u003c/h2\u003e \u003cp\u003eThere was statistically significant difference in the actual ability to kneel in the postoperative period between the two groups (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The highest percentage of \u0026ldquo;good\u0026rdquo; actual kneeling ability was \u0026ldquo;90\u0026deg; kneeling on the cushion in the PD group (55.2%) \u0026rdquo; and the lowest percentage of \u0026ldquo;good\u0026rdquo; actual ability was \u0026ldquo;120\u0026deg; kneeling on the floor in the non-PD group (16.1%)\u0026rdquo;. The highest percentage of actual inability to kneel was \u0026ldquo;on the floor in the non-PD group (24.2%)\u0026rdquo;, and the lowest percentage was \u0026ldquo;on the cushion in the PD group (6.9%)\u0026rdquo;.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of postoperative kneeling scores for Question 7 of the Oxford Knee Score\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eImpossible\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePoor\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGood\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e-Value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e90\u0026deg; Kneeling (Cushion)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.029\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4 (6.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e22 (37.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e32 (55.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-PD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e10 (16.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e29 (46.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e23 (37.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e120\u0026deg; Kneeling (Cushion)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.018\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4 (6.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e25 (43.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e29 (50.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-PD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e10 (16.1) 11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e33 (53.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e19 (30.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e90\u0026deg; Kneeling (Floor)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.038\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7 (12.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e31 (53.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e20 (34.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-PD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e15 (24.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e34 (54.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e13 (21.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e120\u0026deg; Kneeling (Floor)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e0.031\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7 (12.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e34 (58.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e17 (29.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon-PD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e15 (24.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e37 (59.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10 (16.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eBold values indicate statistically significant values (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003eThere was significant difference between the perceived and actual performance of the two groups (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The highest concordance between patients' actual kneeling performance being \u0026ldquo;good\u0026rdquo; and perceiving that they could kneel was \u0026ldquo;120\u0026deg; kneeling on the cushion in the PD group (89.7%) \u0026rdquo;, and the worst concordance was \u0026ldquo;90\u0026deg; kneeling on the floor in the non-PD group (69.2%) \u0026rdquo;. The highest concordance between patients' actual inability to kneel and their perceived inability to kneel was \"kneeling on the cushion in the PD group (100%)\", and the worst concordance was \"kneeling cushion in the non-PD group (80%)\".\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003ePostoperative complications\u003c/h2\u003e \u003cp\u003eDuring the perioperative period, the intervention group and conventional group had 3 cases of lower extremity vein thrombosis (1 and 2, respectively), 1 case of hematoma (0 and 1, respectively) and 3 cases of poorly healed skin incisions (1 and 2, respectively). The patients were cured after symptomatic treatment, and none of them underwent secondary surgical revision. The incidence of postoperative complications was 5.2% (3/58) in the PD group and 6.5% (4/62) in the non-PD group. The difference between the two groups was not statistically significant (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.537). There were no postoperative complications, such as infection, fracture, patellar necrosis, or implant loosening, in either group during the follow-up period.\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe findings in this study were consistent with the hypothesis. UKA patients treated with PD achieved better Kujiala scores and FJS-12 scores, reduced anterior knee pain and improved kneeling ability postoperatively, validating the effectiveness of PD in UKA. Perception and actual performance of kneeling remained mismatched in PD patients, but performance during different kneeling activities was generally better than in non-PD patients. No postoperative complications due to peripatellar electrocautery were found in UKA patients who underwent PD treatment, indicating the safety of PD in UKA.\u003c/p\u003e \u003cp\u003ePD can effectively reduce postoperative AKP, but the pathogenesis of postoperative AKP has not been fully elucidated, and it is generally believed that substance-p nerve fibres in the peripatellar soft tissue are the main cause. Substance P, an nociceptive neurotransmitter found in afferent nerve fibres, is predominantly found in the the patellar retinaculum, fat pad, periosteum, and cartilage affected by degenerative diseases[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Therefore, pain receptor desensitization through peripatellar electrocautery can reduce pain transmission. In addition, peripatellar soft tissue traction or bony structure compression may cause nerve fibre edema and degeneration, as well as intraoperative traction and suturing may easily produce peripheral neuralgia, increasing the risk of postoperative pain. The denervation technique can partially terminate the potential pain pathway and reduce the occurrence of pain.\u003c/p\u003e \u003cp\u003eThe effectiveness of PD is currently controversial. Our study revealed that patients who underwent PD had better patellar scores, greater joint forgetting and less pain. However, some studies have suggested that these improvements may not be durable. However, some studies have suggested that these improvements may not be long-lasting. A meta-analysis by Yuan et al [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] showed that the effective effect of PD was limited to 12 months postoperatively, but a meta-analysis by Duan et al [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e] demonstrated that the effect of PD can extend beyond 12 months. As severe patellofemoral joint degeneration (PFJD) is widely considered a contraindication to UKA, all the patients included in this study did not have severe PFJD. However, a prospective study by Suwankomonkul et al [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] showed that UKA patients with severe PFJD who received PD also had favourable outcomes in the short term. It is worth noting that Pongcharoen et al [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e] conducted a prospective comparison of patients with severe and non-severe PFJD treated with UKA, and the results showed that patients with severe PFJD had poorer knee joint scores. In addition, Hamilton et al [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e] reported up to 15 years of follow-up in UKA patients that severe PFJD may have a negative impact on descending stairs. Considering the unsustainable effectiveness of PD and the long-term adverse outcomes of severe PFJD, UKA in combination with PD is not recommended as the preferred option for patients with bicompartmental lesions.\u003c/p\u003e \u003cp\u003ePD patients showed significant improvement in kneeling ability after surgery. The results also further confirm the findings of the Artz et al [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] study that there is a correlation between kneeling ability, pain and function. The causes of kneeling difficulties are multifaceted; in addition to pain and function, numbness, fear of injury to the prosthesis, comorbidities and third-party recommendations can all contribute to limitations in kneeling [\u003cspan additionalcitationids=\"CR29 CR30\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Many healthcare professionals advise patients not to kneel due to concerns about the safety of kneeling, but there is no clinical evidence of an association between kneeling and prosthesis loosening. This and other studies have found discrepancies between patients' self-perceived ability to kneel and their actual ability to observe [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Although some patients may perceive an inability to kneel, many patients actually have the potential to kneel after appropriate rehabilitation training and instruction[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Therefore, while PD improves the ability to kneel by improving the patient's function and reducing AKP, there is still a need for acquired help to build confidence and overcome kneeling difficulties through a comprehensive rehabilitation programme, individualized education and advice, and effective physiotherapy.\u003c/p\u003e \u003cp\u003eIn this study, the application of PD in UKA was not found to increase the occurrence of related complications. However, during electrocautery denervation in the peripatellar region, it may cause damage to the nutrient vessels around the patella, increasing the risk of patellar necrosis and fracture [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. Therefore, the operator should be familiar with the distribution of the peripatellar nerves and master the range and depth of electrocautery. Before peripatellar electrocautery, we bent the metal tip of the electrotome tip by 3 mm. This not only prevents the patella from completely turning over, but also controls the depth of electrocautery and avoids damage caused by nerve regeneration and excessive electrocautery.\u003c/p\u003e \u003cp\u003eThis study inevitably has several limitations. First, the short follow-up period of this study did not allow for observation of long-term outcomes or complications. Second, this study transformed the five-categorical variables into three-categorical variables in assessing the ability to kneel. Although the multicategorical transformation can simplify model building and interpretation, it may cause limitations in the reliability and interpretability of the results. In addition, this study was evaluated only through four simple kneeling activities and lacked multidimensional tests of kneeling ability. Therefore, there is still a need for long-term prospective studies to validate PD in UKA and more comprehensive tests to assess kneeling ability in the future.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003ePatellar denervation can safely and effectively improve patellofemoral joint function, pain and kneeling ability in the early postoperative period after UKA.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eUKA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eunicompartmental knee arthroplasty\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003ePD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003epatellar denervation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eHSS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eHospital for Special Surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eVAS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003evisual analogue scale\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eFJS-12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eforgotten joint score\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eAKP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eanterior knee pain\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003ePFJD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003epatellofemoral joint degeneration\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eASA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eAmerican Society of Anesthesiologists\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eCCI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"50%\" valign=\"top\"\u003e\n \u003cp\u003eCharlson comorbidity index\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e \u003cp\u003e This study has been approved by the Ethics Committee of Xuzhou Medical University Affiliated Hospital.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent for publication\u003c/strong\u003e \u003cp\u003e All eligible participants signed an informed consent form prior to surgery.\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis study was funded by the Youth medical science and technology innovation project of Xuzhou Health Commission (XWKYHT20210577) and Affiliated Hospital of Xuzhou Medical College (2020104734).\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eSYJ analyzed the data and wrote the manuscript. HL and LN was responsible for data collection and collation. CXY provided supervision and guidance on the content of research topics. FS and ZS made significant contributions to the conception and design of the study, and critically revised the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eJenny J-Y. Minimally invasive unicompartmental knee arthroplasty. Eur J Orthop Surg Traumatol 2018;28:793\u0026ndash;7. https://doi.org/10.1007/s00590-017-2107-5.\u003c/li\u003e\n\u003cli\u003eGe J, Hernigou P, Guo W, Zhang N, Liu C, Zhang Q. Minimally invasive small incision surgical technique for unicompartmental knee arthroplasty. Int Orthop 2023;47:2717\u0026ndash;25. https://doi.org/10.1007/s00264-023-05908-5.\u003c/li\u003e\n\u003cli\u003eAl-Dadah O, Hing C. Unicompartmental Knee Arthroplasty: General trends of clinical practice. Knee 2023;41:A1\u0026ndash;2. https://doi.org/10.1016/j.knee.2023.03.013.\u003c/li\u003e\n\u003cli\u003eKnifsund J, Niinimaki T, Nurmi H, Toom A, Keemu H, Laaksonen I, et al. Functional results of total-knee arthroplasty versus medial unicompartmental arthroplasty: two-year results of a randomised, assessor-blinded multicentre trial. BMJ Open 2021;11:e046731. https://doi.org/10.1136/bmjopen-2020-046731.\u003c/li\u003e\n\u003cli\u003eBarker KL, Hannink E, Pemberton S, Jenkins C. Knee Arthroplasty Patients Predicted Versus Actual Recovery: What Are Their Expectations About Time of Recovery After Surgery and How Long Before They Can Do the Tasks They Want to Do? Arch Phys Med Rehabil 2018;99:2230\u0026ndash;7. https://doi.org/10.1016/j.apmr.2018.03.022.\u003c/li\u003e\n\u003cli\u003eScott CEH, Bugler KE, Clement ND, MacDonald D, Howie CR, Biant LC. Patient expectations of arthroplasty of the hip and knee. J Bone Joint Surg Br 2012;94:974\u0026ndash;81. https://doi.org/10.1302/0301-620X.94B7.28219.\u003c/li\u003e\n\u003cli\u003eArtz NJ, Hassaballa MA, Robinson JR, Newman JH, Porteous AJ, Murray JRD. Patient Reported Kneeling Ability in Fixed and Mobile Bearing Knee Arthroplasty. J Arthroplasty 2015;30:2159\u0026ndash;63. https://doi.org/10.1016/j.arth.2015.06.063.\u003c/li\u003e\n\u003cli\u003eWeiss JM, Noble PC, Conditt MA, Kohl HW, Roberts S, Cook KF, et al. What functional activities are important to patients with knee replacements? Clin Orthop Relat Res 2002:172\u0026ndash;88. https://doi.org/10.1097/00003086-200211000-00030.\u003c/li\u003e\n\u003cli\u003eWojtys EM, Beaman DN, Glover RA, Janda D. Innervation of the human knee joint by substance-P fibers. Arthroscopy 1990;6:254\u0026ndash;63. https://doi.org/10.1016/0749-8063(90)90054-h.\u003c/li\u003e\n\u003cli\u003eMaralcan G, Kuru I, Issi S, Esmer AF, Tekdemir I, Evcik D. The innervation of patella: anatomical and clinical study. Surg Radiol Anat 2005;27:331\u0026ndash;5. https://doi.org/10.1007/s00276-005-0334-7.\u003c/li\u003e\n\u003cli\u003eBudhiparama NC, Hidayat H, Novito K, Utomo DN, Lumban-Gaol I, Nelissen RGHH. Does Circumferential Patellar Denervation Result in Decreased Knee Pain and Improved Patient-reported Outcomes in Patients Undergoing Nonresurfaced, Simultaneous Bilateral TKA? Clin Orthop Relat Res 2020;478:2020\u0026ndash;33. https://doi.org/10.1097/CORR.0000000000001035.\u003c/li\u003e\n\u003cli\u003eSuwankomonkul P, Arirachakaran A, Kongtharvonskul J. Short-term improvement of patellofemoral pain in medial unicompartmental knee arthroplasty with patellar denervation: a prospective comparative study. Musculoskelet Surg 2022;106:75\u0026ndash;82. https://doi.org/10.1007/s12306-020-00675-7.\u003c/li\u003e\n\u003cli\u003eAlomran A. Effect of patellar denervation on mid-term results after non-resurfaced total knee arthroplasty. A randomised, controlled trial. Acta Orthop Belg 2015;81:609\u0026ndash;13.\u003c/li\u003e\n\u003cli\u003evan Jonbergen H-PW, Reuver JM, Mutsaerts EL, Poolman RW. Determinants of anterior knee pain following total knee replacement: a systematic review. Knee Surg Sports Traumatol Arthrosc 2014;22:478\u0026ndash;99. https://doi.org/10.1007/s00167-012-2294-x.\u003c/li\u003e\n\u003cli\u003eYuan M-C, Ding Z-C, Ling T-X, Zhou Z. Patellar Denervation with Electrocautery Reduces Anterior Knee Pain within 1 Year after Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials. Orthop Surg 2021;13:14\u0026ndash;27. https://doi.org/10.1111/os.12735.\u003c/li\u003e\n\u003cli\u003eXie X, Pei F, Huang Z, Tan Z, Yang Z, Kang P. Does patellar denervation reduce post-operative anterior knee pain after total knee arthroplasty? Knee Surg Sports Traumatol Arthrosc 2015;23:1808\u0026ndash;15. https://doi.org/10.1007/s00167-015-3566-z.\u003c/li\u003e\n\u003cli\u003eIwano T, Kurosawa H, Tokuyama H, Hoshikawa Y. Roentgenographic and clinical findings of patellofemoral osteoarthrosis. With special reference to its relationship to femorotibial osteoarthrosis and etiologic factors. Clin Orthop Relat Res 1990:190\u0026ndash;7.\u003c/li\u003e\n\u003cli\u003eKujala UM, Jaakkola LH, Koskinen SK, Taimela S, Hurme M, Nelimarkka O. Scoring of patellofemoral disorders. Arthroscopy 1993;9:159\u0026ndash;63. https://doi.org/10.1016/s0749-8063(05)80366-4.\u003c/li\u003e\n\u003cli\u003eRanawat CS, Insall J, Shine J. Duo-condylar knee arthroplasty: hospital for special surgery design. Clin Orthop Relat Res 1976:76\u0026ndash;82.\u003c/li\u003e\n\u003cli\u003eHawker GA, Mian S, Kendzerska T, French M. Measures of adult pain: Visual Analog Scale for Pain (VAS Pain), Numeric Rating Scale for Pain (NRS Pain), McGill Pain Questionnaire (MPQ), Short-Form McGill Pain Questionnaire (SF-MPQ), Chronic Pain Grade Scale (CPGS), Short Form-36 Bodily Pain Scale (SF-36 BPS), and Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP). Arthritis Care Res (Hoboken) 2011;63 Suppl 11:S240-252. https://doi.org/10.1002/acr.20543.\u003c/li\u003e\n\u003cli\u003eThienpont E, Opsomer G, Koninckx A, Houssiau F. Joint awareness in different types of knee arthroplasty evaluated with the Forgotten Joint score. J Arthroplasty 2014;29:48\u0026ndash;51. https://doi.org/10.1016/j.arth.2013.04.024.\u003c/li\u003e\n\u003cli\u003eBehrend H, Giesinger K, Giesinger JM, Kuster MS. The \u0026ldquo;forgotten joint\u0026rdquo; as the ultimate goal in joint arthroplasty: validation of a new patient-reported outcome measure. J Arthroplasty 2012;27:430-436.e1. https://doi.org/10.1016/j.arth.2011.06.035.\u003c/li\u003e\n\u003cli\u003eDawson J, Fitzpatrick R, Murray D, Carr A. Questionnaire on the perceptions of patients about total knee replacement. J Bone Joint Surg Br 1998;80:63\u0026ndash;9. https://doi.org/10.1302/0301-620x.80b1.7859.\u003c/li\u003e\n\u003cli\u003eWitoński D, Wagrowska-Danielewicz M. Distribution of substance-P nerve fibers in the knee joint in patients with anterior knee pain syndrome. A preliminary report. Knee Surg Sports Traumatol Arthrosc 1999;7:177\u0026ndash;83. https://doi.org/10.1007/s001670050144.\u003c/li\u003e\n\u003cli\u003eDuan G, Liu C, Lin W, Shao J, Fu K, Niu Y, et al. Different Factors Conduct Anterior Knee Pain Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis. J Arthroplasty 2018;33:1962-1971.e3. https://doi.org/10.1016/j.arth.2017.12.024.\u003c/li\u003e\n\u003cli\u003ePongcharoen B, Reutiwarangkoon C. The comparison of anterior knee pain in severe and non severe arthritis of the lateral facet of the patella following a mobile bearing unicompartmental knee arthroplasty. Springerplus 2016;5:202. https://doi.org/10.1186/s40064-016-1914-1.\u003c/li\u003e\n\u003cli\u003eHamilton TW, Pandit HG, Maurer DG, Ostlere SJ, Jenkins C, Mellon SJ, et al. Anterior knee pain and evidence of osteoarthritis of the patellofemoral joint should not be considered contraindications to mobile-bearing unicompartmental knee arthroplasty: a 15-year follow-up. Bone Joint J 2017;99-B:632\u0026ndash;9. https://doi.org/10.1302/0301-620X.99B5.BJJ-2016-0695.R2.\u003c/li\u003e\n\u003cli\u003eHassaballa MA, Porteous AJ, Newman JH. Observed kneeling ability after total, unicompartmental and patellofemoral knee arthroplasty: perception versus reality. Knee Surg Sports Traumatol Arthrosc 2004;12:136\u0026ndash;9. https://doi.org/10.1007/s00167-003-0376-5.\u003c/li\u003e\n\u003cli\u003eFletcher D, Moore AJ, Blom AW, Wylde V. An exploratory study of the long-term impact of difficulty kneeling after total knee replacement. Disabil Rehabil 2019;41:820\u0026ndash;5. https://doi.org/10.1080/09638288.2017.1410860.\u003c/li\u003e\n\u003cli\u003eWhite L, Stockwell T, Hartnell N, Hennessy M, Mullan J. Factors preventing kneeling in a group of pre-educated patients post total knee arthroplasty. J Orthop Traumatol 2016;17:333\u0026ndash;8. https://doi.org/10.1007/s10195-016-0411-1.\u003c/li\u003e\n\u003cli\u003eMacDonald B, Kurdin A, Somerville L, Ross D, MacDonald S, Lanting B. The Effect of Sensory Deficit After Total Knee Arthroplasty on Patient Satisfaction and Kneeling Ability. Arthroplast Today 2021;7:264-267.e2. https://doi.org/10.1016/j.artd.2020.11.020.\u003c/li\u003e\n\u003cli\u003eNarkbunnam R, Rojjananukulpong K, Ruangsomboon P, Chareancholvanich K, Pornrattanamaneewong C. The association between perception of patients and their actual ability to do floor activities after mobile-bearing unicompartmental knee arthroplasty: A prospective, cross-sectional study. Jt Dis Relat Surg 2023;34:245\u0026ndash;52. https://doi.org/10.52312/jdrs.2023.877.\u003c/li\u003e\n\u003cli\u003eSchai PA, Gibbon AJ, Scott RD. Kneeling ability after total knee arthroplasty. Perception and reality. Clin Orthop Relat Res 1999:195\u0026ndash;200.\u003c/li\u003e\n\u003cli\u003eJenkins C, Barker KL, Pandit H, Dodd CAF, Murray DW. After partial knee replacement, patients can kneel, but they need to be taught to do so: a single-blind randomized controlled trial. Phys Ther 2008;88:1012\u0026ndash;21. https://doi.org/10.2522/ptj.20070374.\u003c/li\u003e\n\u003cli\u003eRussell RD, Huo MH, Jones RE. Avoiding patellar complications in total knee replacement. Bone Joint J 2014;96-B:84\u0026ndash;6. https://doi.org/10.1302/0301-620X.96B11.34305.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"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":"unicompartmental knee arthroplasty, patellar denervation, anterior knee pain, kneel","lastPublishedDoi":"10.21203/rs.3.rs-4738535/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4738535/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjective\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe aim of this study was to investigate the effect of patellar denervation (PD) on pain, function and ability to kneel after unicompartmental knee arthroplasty (UKA).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients with medial knee osteoarthritis who underwent UKA were prospectively selected. Patients were divided into PD and non-PD groups based on whether patellar denervation was performed. Clinical assessment was performed using the Hospital for Special Surgery (HSS) knee score, Kujiala score, visual analogue scale (VAS) and forgotten joint score (FJS-12), as well as postoperative complications were recorded. The patients' postoperative self-perception and actual ability to perform different kneeling positions were assessed in the two groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUKA patients treated with PD achieved better Kujiala scores and FJS-12 scores, reduced anterior knee pain and improved kneeling ability postoperatively, validating the effectiveness of PD in UKA. Perception and actual performance of kneeling remained mismatched in PD patients, but performance during different kneeling activities was generally better than in non-PD patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatellar denervation can safely and effectively improve patellofemoral joint function, pain and kneeling ability in the early postoperative period after UKA.\u003c/p\u003e\n\u003cp\u003eClinical Trial Registration: ChiCTR1900025669\u003c/p\u003e","manuscriptTitle":"The Efficacy of Patellar Denervation on Prognosis and Kneeling Capacity after Unicompartmental Knee Arthroplasty: A Randomized Clinical Trial","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-08-16 21:20:30","doi":"10.21203/rs.3.rs-4738535/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-07-22T06:48:53+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-07-21T09:01:19+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-07-18T16:32:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"131922159117850047873554026581698906148","date":"2024-07-18T10:33:01+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"326851313123684983290296989219035979751","date":"2024-07-16T08:21:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"337906724036649888317785652256141945443","date":"2024-07-16T08:03:30+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-07-16T07:58:27+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-07-16T07:36:08+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-07-16T07:25:30+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Orthopaedic Surgery and Research","date":"2024-07-14T13:12:17+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":"98f38e15-2b19-4df1-8a0a-ac1c948eca39","owner":[],"postedDate":"August 16th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-10-07T16:04:30+00:00","versionOfRecord":{"articleIdentity":"rs-4738535","link":"https://doi.org/10.1186/s13018-024-05015-0","journal":{"identity":"journal-of-orthopaedic-surgery-and-research","isVorOnly":false,"title":"Journal of Orthopaedic Surgery and Research"},"publishedOn":"2024-10-05 15:57:08","publishedOnDateReadable":"October 5th, 2024"},"versionCreatedAt":"2024-08-16 21:20:30","video":"","vorDoi":"10.1186/s13018-024-05015-0","vorDoiUrl":"https://doi.org/10.1186/s13018-024-05015-0","workflowStages":[]},"version":"v1","identity":"rs-4738535","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4738535","identity":"rs-4738535","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}