Search

Introduction: The current literature is mixed on which patient factors, if any, predict the rate of successful discharge within 24 h of enhanced recovery after surgery (ERAS) total knee arthroplasty (TKA). This study aimed to investigate the influence of timing of surgery and physiotherapy on the rate of successful 24-h discharge., Methods: All 342 patients who underwent ERAS day surgery TKA from August 2020 to July 2021 were followed up prospectively. Patient characteristics and postoperative outcomes, such as number of physiotherapy sessions required before clearance for home, time taken after surgery to ambulate >10 m and length of stay (LOS), were recorded. Patients were grouped based on surgical end time (morning/afternoon/ evening) and time of physiotherapy review (morning/afternoon/evening/morning after). Patients successfully passed ERAS day surgery protocol if they were discharged within 24 h., Results: With regard to the timing of operation, the morning group had the shortest LOS (P = 0.001) and a higher ERAS day surgery pass rate than the afternoon group (P = 0.016). With regard to the timing of physiotherapy, the afternoon group took the shortest time to ambulate >10 m (P < 0.001), had the shortest LOS (P < 0.001) and had a higher ERAS day surgery pass rate as compared to the morning after the operation group (P = 0.005)., Conclusion: Patients who ended their operations in the morning and received physiotherapy review in the same afternoon were the most likely to be discharged within 24 h due to early ambulation and adequate time for spinal anaesthesia to wear off., (Copyright © 2024 Copyright: © 2024 Singapore Medical Journal.)

Identifying and preventing patients who are not likely to benefit long-term from total knee arthroplasty (TKA) would decrease healthcare expenditure significantly. We trained machine learning (ML) models (image-only, clinical-data only, and multimodal) among 5720 knee OA patients to predict postoperative dissatisfaction at 2 years. Dissatisfaction was defined as not achieving a minimal clinically important difference in postoperative Knee Society knee and function scores (KSS), Short Form-36 Health Survey [SF-36, divided into a physical component score (PCS) and mental component score (MCS)], and Oxford Knee Score (OKS). Compared to image-only models, both clinical-data only and multimodal models achieved superior performance at predicting dissatisfaction measured by AUC, clinical-data only model: KSS 0.888 (0.866-0.909), SF-PCS 0.836 (0.812-0.860), SF-MCS 0.833 (0.812-0.854), and OKS 0.806 (0.753-0.859); multimodal model: KSS 0.891 (0.870-0.911), SF-PCS 0.832 (0.808-0.857), SF-MCS 0.835 (0.811-0.856), and OKS 0.816 (0.768-0.863). Our findings highlighted that ML models using clinical or multimodal data were capable to predict post-TKA dissatisfaction., (© 2024. The Author(s).)

Introduction: Unicompartmental Knee Arthroplasty (UKA) has become popular due to faster recovery and improved range of motion. However, concerns have been made regarding increased risk of early failure. Furthermore, the use of Enhanced Recovery After Surgery (ERAS) protocols have shown to allow faster return to activities, improved satisfaction, and reduced complication rates.This study aims to compare the 6 month functional outcomes of patients undergoing Total Knee Replacement (TKR) versus UKA under the ERAS protocol., Methods: Patient characteristics and comorbidities, 30-day post-operation readmission and infection rates were analyzed. Patient reported outcomes measures namely the Knee Society Function and Knee Score (KSFS, KSKS), Oxford Knee Score (OKS) and both the Physical and Mental component of the Short-Form Health Survey (SF-36) were assessed pre-operatively and 6 months post-operatively.Univariate analysis was used to compare differences in characteristics and comorbidities between the 2 groups. Finally, a multiple linear regression was performed to compare the post-operative outcomes., Results: Univariate analysis showed significantly better preoperative and 6 month post-operative KSKS and SF-36 MCS in UKA patients. Multivariate analysis showed no difference in the 6 month post-operative functional outcome scores between UKA and TKR patients. No UKA patients required revision surgery while 4 TKR patients required revision surgery for infection., Conclusion: UKA achieves equivalent functional outcomes at 6 months post-operatively as compared to TKR patients and has lower infection rates. UKA is a reasonable option to offer for unicompartmental knee osteoarthritis patients., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Background: Arthrofibrosis is a common postoperative total knee arthroplasty (TKA) complication that results in limited range of motion (ROM). There is limited literature on outcomes after revision TKA (rTKA) for arthrofibrosis based on preoperative ROM restriction. The aims of this study were to: (1) examine ROM trajectory after rTKA for arthrofibrosis patients who have severe versus nonsevere limitations; (2) compare ROM gains and final arc of motion (AOM) between severe and nonsevere cohorts; (2a) compare ROM gain in a severe cohort treated with a rotating hinge (RH) versus a non-RH (NRH) construct; and (3) assess the impact of arthrofibrosis severity on patient-reported outcome measures., Methods: Patients were divided into 2 groups: group A had preoperative ROM < 70 ° (severe), and group B had preoperative ROM > 70 ° (non-severe). Patients were assessed clinically using AOM gain, absolute ROM, Knee injury and Osteoarthritis Outcomes Score for Joint Replacement, lower extremity activity scale, and pain scores. Postoperative gains in AOM were compared between both groups., Results: A total of 56 rTKAs (group A (severe): n = 36, group B (non-severe): n = 20) were performed for patients who have postoperative fibrosis. Group B had better ROM at the 1-year time point (group B: 95.9 ± 22.5 degrees versus group A: 83.2 ± 25.7 degrees). Group A had significantly better improvement in absolute AOM than group B (31.1 ± 20.9 versus 11.4 ± 25.0 degrees, P < 0.01). The RH group demonstrated significantly better absolute AOM gain than the NRH group (41.3 ± 19.4 versus 18.3 ± 15.2 degrees, P < 0.001). However, there were no significant differences in patient-reported outcome measures between groups A and B or between RH and NRH groups at the final follow-up., Conclusions: Final ROM achieved between severe and nonsevere arthrofibrosis groups was similar, and patients who have severe arthrofibrosis can expect greater absolute ROM gains and similar functional outcomes than nonsevere arthrofibrosis patients. The RH rTKAs provided greater AOM gains for patients who have severe arthrofibrosis, with equivalent functional outcomes to non-RH implants. For severe arthrofibrosis patients, RH designs provided twice the overall ROM gain; however, longer follow-up is necessary to determine whether RH designs have inferior overall implant survivorship., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Extensor mechanism (EM) disruption is a rare but severe complication of total knee arthroplasty (TKA) that can greatly impair function. Treatment options for chronic patella tendon ruptures include primary repair, autograft augmentation, and reconstruction with allograft or synthetic material. Despite various techniques, failures can occur, and options for reconstruction after a failed allograft or mesh are limited, especially if the tibial component is well-fixed and cannot be easily removed, and if there is proximal tibial deficiency from a previous failed EM allograft. This case report presents a novel solution for revision EM reconstruction in a 72y.o. female patient with a history of multiple EM failures using an off-label Trabecular Metal Cone-Mesh-Cone (TM CMC) clamshell construct. The surgical procedure involved the removal of a non-viable allograft from the knee joint and the creation of a custom trabecular metal (TM) clamshell construct with a Marlex mesh graft in between the two TM implants. The customized TM cone was designed to cover the deficient anterior tibia and wrap around the ingrown TM cone. The Marlex mesh was cemented between the existing implant and the customized TM cone, and the construct was secured in place with two cancellous screws. The mesh was tunneled between soft tissue to prevent contact with the implant and rotated scar tissue was interposed to prevent abrasion of the mesh on the implant surfaces. The patient tolerated the procedure well and no complications were noted postoperatively. At a follow-up 12 months after the operation the patient remains satisfied with the result., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: The patient acceptable symptom state (PASS) refers to a cutoff value on any patient-reported outcome measures (PROMs) scale, beyond which patients consider themselves as having achieved an acceptable outcome. This study aimed to identify PASS thresholds for knee-specific and generic PROMs at 10 years post-unicompartmental knee arthroplasty (UKA)., Methods: There were 269 patients who underwent UKA for medial osteoarthritis from 2004 to 2007 at a single institution and were surveyed preoperatively and 10 years postoperatively using the Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Oxford Knee Score (OKS), 36-Item Short Form Survey (SF-36) Mental Component Score (MCS), and SF-36 Physical Component Score (PCS). Treatment outcomes and expectations were assessed using an anchor question, and PASS attainment was determined using the Youden index on a receiver operating characteristic (ROC) curve. Also, a similar study that identified 2-year long-term PROM PASS thresholds for UKA was referenced and compared., Results: Overall, 91.1% reported acceptable outcomes. The area under the curve for ROCs of KSKS, OKS, and PCS were 0.80, 0.75, and 0.71, respectively. The area under the curve for ROCs of KSFS and MCS were both 0.64. The PASS thresholds were 67.5 for KSFS, 70.5 for KSKS, 39.5 for OKS, 44.6 for PCS, and 43.8 for MCS. Patients who achieved a PASS were at least 3 times more likely to have satisfactory outcomes., Conclusions: To our knowledge, this is the first study that identified 10-year long-term PROM PASS thresholds for UKA. Accounting for our finding that a decade-long follow-up yielded lower PASS thresholds, time-specific UKA PROM PASS thresholds should be considered., Level of Evidence: III., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: Robotic-assisted Total Knee Arthroplasty (TKA) was designed to improve implant position accuracy by providing surgeons with real-time intra-operative data to tailor the operation to the patient. Proponents of robotic-assisted TKA believe that this translates into meaningful improvements in outcomes. However, there are concerns that the longer surgical duration associated with robotic-assisted TKA leads to longer length of stay (LOS). In this study, the authors investigated the outcome of MAKO® Robotic-arm Assisted TKA combined with ERAS protocol to assess its effect on LOS and short-term outcomes., Methods: All patients who had undergone unilateral MAKO® ERAS Day Surgery TKA from August 2020 to July 2021 were prospectively followed up and matched to patients who underwent conventional ERAS Day Surgery TKA in the same time period. Factors such as surgical duration, LOS, immediate reduction in pain, 30-days complications, and 6-month PROMs and knee ROM were compared between the two groups., Results: 42 patients underwent MAKO® ERAS Day surgery TKA and were matched to 42 patients who underwent conventional ERAS Day surgery TKA. The study found that despite the longer surgical duration, LOS was comparable between both groups (1.1 ± 0.9days in the MAKO® group vs 1.0 ± 0.3days in the conventional group, p = 0.755) with successful 24-hour discharge in 88.1 % of patients in the MAKO® group. The MAKO® group achieved significantly better ROM compared to the conventional group 6-months post operatively. Post-operative PROMs were comparable between both groups., Conclusion: ERAS Day Surgery protocol can significantly reduce the LOS of patient undergoing MAKO® Robotic-arm Assisted TKA, conferring cost savings and making it a valid option for patients., Competing Interests: Ng Ee Chern has no financial or non-financial interests to disclose. Dr Xu Sheng has no financial or non-financial interests to disclose. Dr Liu Xuan Eric has no financial or non-financial interests to disclose. Dr Lim Jason Beng Teck has no financial or non-financial interests to disclose. A/Prof Liow Ming Han Lincoln has no financial or non-financial interests to disclose. A/Prof Pang Hee Nee is a paid consultant for Stryker Singapore and Zimmer Biomet. A/Prof Tay Darren Keng Jin is a paid consultant for Stryker Singapore. Prof Yeo Seng Jin is a paid consultant for DepuySynthes and Johnson & Johnson. A/Prof Chen Jerry Yongqiang is a paid consultant for Zimmer Biomet and DepuySynthes., (© 2024 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Introduction: Enhanced recovery after surgery (ERAS) has been increasingly adopted in orthopaedic surgery. Although not an exclusion criterion, patients undergoing total knee arthroplasty (TKA) with preoperative severe varus deformity may be less likely to be enrolled for ERAS. This study aimed to compare the success of ERAS TKA between patients with severe preoperative varus deformities (≥ 15° varus) and the control group (< 15° varus to 14° valgus). Our secondary aim was to compare postoperative complications and functional outcomes between the two groups., Materials & Methods: 310 TKAs performed from August 2019 to February 2021 were analyzed with a follow-up of 6 months postoperatively. The primary outcome, ERAS TKA success, was defined as length of hospital stay of < 24 h. Other parameters included 30-day postoperative complications and clinical outcomes such as the original Oxford Knee Score (OKS), the Knee Society Knee (KSKS) and Function Score (KSFS), Visual Analog Scale for Pain (VAS-P), 36-Item Short-Form Health Survey (SF-36) Physical Component Summary (PCS) and SF-36 Mental Component Summary (MCS)., Results: There were 119 patients in the severe deformity group and 191 patients in the control group. There were no significant differences in ERAS success between the severe deformity group and control group, with both groups achieving similarly high rates (> 90%) of ERAS success. There were also no differences in 30-day postoperative complications and 6-month postoperative clinical outcomes., Conclusion: Patients with severe preoperative varus deformity undergoing ERAS TKA achieved high ERAS success rates (> 90%). Genu varum is not a contraindication for ERAS TKA., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Elective surgeries were postponed during the COVID-19 pandemic to alleviate healthcare strains, affecting majority of elective orthopaedic surgeries such as total knee arthroplasties (TKAs). The aim of this study is to evaluate the impact on knee function and quality of life of patients who had their planned TKA postponed due to the pandemic., Methods: This is a retrospective analysis of data collected in a tertiary hospital. Patients included were diagnosed with primary knee osteoarthritis and they were initially scheduled for primary TKA between January to April 2020 but surgery was postponed by at least 6 months from the initial operative date. 160 patients were included in this study (53 males and 107 females, mean age 68.0 ± 8.1). Patients were assessed prior to initial surgery date and assessed again, prior to the postponed surgery date. Clinical scores included Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Oxford Knee scores (OKS) and Short-Form 36 Physical and Mental Component Scores. (SF36 PCS and MCS). Paired T-test was performed for parametric data whereas Wilcoxon signed-rank analysis was performed for non-parametric data., Results: Comparing initial preoperative versus postponement preoperative scores, the cohort had significantly poorer KSKS (38.4 ± 15.4 and 36.5 ± 15.4, p = 0.034), SF36 PCS (34.3 ± 9.2 and 32.7 ± 8.6, p = 0.02) and OKS (34.9 ± 0.77 and 35.8 ± 8.6, p = 0.02) scores respectively., Conclusion: The postponement of elective TKAs has resulted in a significant deterioration of knee scores and physical quality of live scores of patients in a short span of 6 months. Further studies can evaluate if there are repercussions on long term TKAs outcomes., Level of Evidence: Retrospective study, Level III., (© 2024 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Introduction: The preclusion of obese patients from unicompartmental knee arthroplasty (UKA) has increasingly been challenged. This study aimed to evaluate the impact of Body Mass Index (BMI) on UKA at 15-year follow-up., Materials and Methods: 169 unilateral UKA patients from 2003 to 2007 were followed-up prospectively for at least 15 years. 70 patients were left for analysis after accounting for patient demise, revision surgery and loss to follow-up. 48 of these patients (69%) were in the Control group (BMI <30 kg/m 2 ) and 22 (31%) were in the Obese group (BMI ≥30 kg/m 2 ). Patients were assessed before and after operation using the Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Oxford Knee Score (OKS), and Physical (PCS) and Mental (MCS) component of the Short Form 12. Survivorship analysis was also performed., Results: Obese patients went through UKA at an earlier age than the non-obese patients (54.7 ± 4.7 years compared to 59.9 ± 7.8 years, p = 0.005). At 2, 10, and 15-year follow-up, both groups achieved clinically significant improvements in outcomes. There was no significant association found between obesity and outcome using multiple linear regression. While propensity matching found PCS improvement at 2 years to be greater in obese patients, no significant association between obesity and 15-year outcome was found. All 13 patients who required revision, underwent total knee arthroplasty (TKA). The overall 15-year survivorship was 74.2% within the obese group and 92.4% within the control group., Conclusion: Compared to non-obese patients, obese patients had poorer 15-year survivorship with greater odds of requiring revision surgery. However, assuming implant survival, obese patients can expect a non-inferior outcome relative to their non-obese counterparts in all patient reported outcome measures 15 years after surgery., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Introduction: Conventional total knee arthroplasty (C-TKA) implants have well-established mid- and long-term outcomes. The novel TKA (N-TKA) implants provide morphogenic implant components with smaller size increments to facilitate anatomical replication. The aim of the study is to evaluate if these advantages provides better clinical outcomes., Materials and Methods: Registry data prospectively collected within a single institution from 2014 to 2018 was reviewed and propensity score matching was performed to match C-TKA to N-TKA. 70 pairs of cruciate retaining (CR) TKA and 116 pairs of posterior stabilized (PS) TKA were identified. Range of motion, SF-36, Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS) and Oxford Knee Score (OKS) were assessed preoperatively, 6 and 24 months postoperatively. Satisfaction was assessed 6 and 24 months postoperatively. Independent T test was performed for parametric data, whereas Wilcoxon rank-sum analysis was performed for non-parametric data., Results: Both C-TKA and N-TKA cohorts demonstrated statistically significant improvement for KSKS, KSFS, OKS and SF-36 at 6 and 24 months postoperatively. C-TKA CR patients had better flexion at 6 months as compared to N-TKA CR (108.7° versus 98.3°, respectively, p = 0.046). At 24 months, there was no difference between C-TKA and N-TKA for range of motion, KSKS, KSFS, OKS and SF-36 PCS, regardless of insert type (p > 0.05)., Conclusions: Both models showed great postoperative improvements in KSFS, KSKS, OKS and SF-36 and have comparable early and mid-term outcomes, suggesting that N-TKAs are suitable substitutes for C-TKA. Longer follow-up studies are required to evaluate the long-term outcomes of N-TKAs., Level of Evidence: lll., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: This study explored the safety and efficacy of Enhanced Recovery After Surgery (ERAS) together with a Day-surgery protocol on some commonly used selection criteria for expedited discharge after Total Knee Arthroplasty (TKA)., Methods: ERAS Day surgery TKA performed between Aug 2020 to July 2021 were included in this study. Discharge within 24 h was considered passing protocol. Complications such as infection, re-admission, and re-operation within 30-days were recorded. Patient demographics, medical comorbidities, and outcome measures at 6-month post-operatively were analysed between those who were successfully discharged within 24 h and those with prolong admission., Results: A total of 342 patients were included in the study. 315 patients (92.1 %) were discharged within 24 h s. Inadequately controlled pain was the most common reason for delayed discharge (17.9 %). No statistically significant difference in gender, age, Charlson Comorbidity Index (CCI), Body Mass Index (BMI), and American Society of Anaesthesiologist Classification (ASA) were noted between patients who failed protocol and those who passed. Readmission rate within 30days was 2.6 %. Infection occurred in 5 cases, including 2 prosthetic joint infection (PJI) requiring debridement, antibiotics, and implant retention (DAIR), 2 surgical site infection treated with antibiotics, and 1 pneumonia. No 30-days complication occurred in patients who initially failed ERAS Day-surgery protocol. Binary logistic regression was statistically insignificant on effect of gender, age, CCI, BMI, and ASA on passing protocol or 30-days complications. Propensity score matching of patients with prolong stay of more than 24 h did not demonstrate any difference in 6-month outcome., Conclusion: Patient characteristics such as gender, age, CCI, BMI, and ASA did not influence successful completion of ERAS Day-surgery protocol. Even if patients were initially enrolled in ERAS Day-surgery protocol but failed to be discharged within 24 h, this did not predispose them to increased 30-days complication or poorer 6-month outcome., Level of Evidence: III., (© 2023 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Background: This study describes the implementation of Enhanced Recovery After Surgery (ERAS) total knee arthroplasty (TKA) with day-surgery protocol to assess the outcome of ERAS day surgery TKA compared with traditional ERAS inpatient TKA in terms of length of stay (LOS), 30-day readmission, complications, and patient-reported outcome measures (PROMs)., Methods: Patients who underwent unilateral primary TKA from August 2020 to July 2021 were followed up. All TKAs were performed with the ERAS protocol. Patients who fulfilled the following inclusion criteria were offered day-surgery protocol: (1) ASA ≤ 3; (2) agreeable for discharge home. In addition, this day-surgery protocol comprised the following: (i) on-call physiotherapy review; (ii) home visit by physiotherapist at 1 week postoperative; (iii) home visit by nurse at 2 weeks postoperative. Day surgery was defined as discharge within 24 h. Patients were followed up for 6 months and PROMs, postoperative complications, and re-admissions recorded., Results: A total of 738 patients were included (342 ERAS day surgery, 396 ERAS inpatient). 92.4% of patients in the day-surgery group were successfully discharged within 24 h, leading to a shorter mean LOS of 1.13 days compared with 4.12 days in the inpatient group (P < 0.005). Both groups achieved significant and comparable improvement in Knee Society Score, Oxford Knee Score, and Physical and Mental component of Short Form-36. Both groups had similar rate of 30-day readmission and complications., Conclusion: Patients who underwent ERAS day surgery TKA achieved similar functional and quality of life improvement compared with ERAS inpatient TKA with no increased complication rate. ERAS day surgery TKA is safe and cost effective, and its use should be promoted., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Robot-assisted total knee arthroplasty (rTKA) may improve clinical outcomes for patients who have end-stage osteoarthritis of the knee. However, the costs of rTKA are high, and there is a paucity of data evaluating the cost-effectiveness of rTKA. We aimed to analyze the cost per quality-adjusted life-year (QALY) of rTKA relative to manual TKA., Methods: A Markov decision analysis was performed using known parameters for costs, outcomes, implant survivorships, and mortalities. The cost-effectiveness of rTKA relative to manual TKA was assessed for end-stage knee osteoarthritis patients who had a mean age of 65 years (range, 27 to 94 years). The rTKA costs were calculated for a pay-per-use contract robot., Results: Using the Markov Model with an annual case volume of 500 patients and a mean age of 65 years, the overall health gain per patient was 13.34 QALYs after rTKA and 13.31 QALYs after manual TKA. This resulted in an overall gain in QALYs of 0.03 for each patient undergoing an rTKA compared with manual TKA and an incremental cost of $128,526 Singapore Dollars per QALY., Conclusion: Robotic TKA is not a cost-effective alternative to conventional TKA using a pay-per-use contract robot., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: Tranexamic acid (TXA) is being increasingly utilized to reduce blood loss after knee joint arthroplasty. However, there is a lack of studies on the effect of topical TXA on the functional outcomes and quality of life after Unicompartmental Knee Arthroplasty (UKA). The aim of this study was to determine the effect of topical TXA on functional outcomes and quality of life scores in patients undergoing UKA., Materials and Methods: We retrospectively analysed patients undergoing unilateral UKA at a single tertiary hospital from 2005 to 2017. Patients were divided into 2 groups: (1) The control group which did not receive TXA (n = 742); (2) The TXA group which received topical TXA (n = 331). Functional outcomes were assessed using the Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS) and Oxford Knee Score (OKS), while quality of life was evaluated with the Physical Component Score (PCS) and Mental Component Score (MCS) of Short-Form 36 (SF-36) preoperatively and at 6 months and 2 years follow-up., Results: At 6 months and 2 years post-surgery, there were no significant differences in the functional scores between the groups. The number of patients who attained minimum clinically important difference (MCID) for each of the functional scores was also comparable between the groups., Conclusions: In patients undergoing UKA, functional outcomes and quality of life scores were comparable between those who received topical TXA and those who did not. There was no significant improvement or impairment in knee function associated with topical TXA administration in UKA up to 2 years follow-up., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The purpose of this study was to (1) longitudinally compare the patient-reported outcome measures (PROMs) of the same patients who underwent primary TKA and revision TKA, and (2) compared the results of these revision TKA with a matched cohort of well-functioning primary TKA. The hypothesis was revision TKA could result in equivalent outcomes to patients' own primary TKA or the primary TKA of patients who did not require revision., Methods: Prospectively collected data of 123 patients who underwent primary TKA and subsequently aseptic revision TKA ("revised group"), were matched using nearest-neighbor method to 123 well-functioning primary TKA that did not require revision ("control group"). Preoperative (prior to primary TKA), at time of failure (prior to revision TKA), postoperative 6-month and 2-year PROMs included Knee Society scores (KSS), Oxford Knee Score (OKS) and Short Form-36 (SF-36). Minimal clinically important difference (MCID) attainment was analyzed. Wilcoxon and McNemar's tests were used to compare outcomes within the revised group (primary vs revision), Mann-Whitney U test and Chi-Square test for the revised and control groups., Results: The revised group had poorer KSS objective (p = 0.045), KSS functional (p < 0.001), OKS (p = 0.011) and SF-36 PCS (p < 0.001) at time of failure (prior to revision TKA), compared to their preoperative PROMs (prior to primary TKA). Revision TKA resulted in restoration of KSS objective, OKS and SF-36 PCS (NS) that were equivalent to their primary TKA, but poorer KSS functional (p < 0.050). Patients in the revised group had a lower proportion of MCID attainment in KSS objective (p = 0.014) and OKS (p < 0.001) at 2-year after primary TKA when compared to the control group. Revision TKA also led to poorer KSS objective, KSS functional and SF-36 PCS (p < 0.050) when compared to primary TKA of the control group., Conclusion: Outcomes following aseptic revision were equivalent to patients' own pre-failure state but inferior to patients with non-revised implants. An individualized approach toward goal setting and assessing adequacy of aseptic revision TKA can be adopted based on patients' pre-failure outcomes., Level of Evidence: III., (© 2021. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Purpose: The patient acceptable symptom state (PASS) is a target value on a patient-reported outcome measures (PROM) scale beyond which patients deem themselves to have attained an acceptable outcome. This study aimed to define the PASS thresholds for generic and knee-specific PROMs at 2 years after unicompartmental knee arthroplasty (UKA)., Methods: Prospectively collected data of 955 patients who underwent UKA for medial osteoarthritis at a single institution was reviewed. Patients were assessed preoperatively and 2 years postoperatively using the Knee Society Knee Score (KSKS), Function Score (KSFS), Oxford Knee Score (OKS), SF-36 Physical Component Score (PCS) and Mental Component Score (MCS). Responses to an anchor question assessing patients' overall rating of treatment results were dichotomized and used to determine if PASS was achieved. PASS thresholds for each PROM were selected based on the Youden index on a receiver operating characteristics (ROC) curve. Sensitivity analyses were performed for different subgroups (by age, gender, BMI), baseline score tertiles and an alternate definition of PASS., Results: In total, 92.7% reported their current state as acceptable. The areas under the curve (AUC) for ROCs were 0.72-0.83, except for the SF-36 PCS (AUC 0.64), indicating good discriminative accuracy of the other PROMs. PASS thresholds were 85.5 for KSKS, 77.5 for KSFS, 41.5 for OKS, 49.9 for SF-36 PCS and 54.6 for SF-36 MCS. Sensitivity analyses revealed that the thresholds were robust. Patients who attained a PASS were at least 4-5 times more likely to be satisfied and have expectations fulfilled., Conclusion: PASS thresholds can be used to define treatment success in future outcome studies. At the individual level, they provide clinically relevant benchmarks for surgeons when assessing postoperative recovery., Level of Evidence: III., (© 2021. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

This study aimed to compare the in-vivo kinematics and articular contact status between medial-pivot total knee arthroplasty (MP-TKA) and posterior stabilized (PS) TKA during weight-bearing single-leg lunge. 16 MP-TKA and 12 PS-TKA patients performed bilateral single-leg lunges under dual fluoroscopy surveillance to determine the in-vivo six degrees-of-freedom knee kinematics. The closest point between the surface models of the femoral condyle and the polyethylene insert was used to determine the contact position and area. The nonparametric statistics analysis was performed to test the symmetry of the kinematics between MP-TKA and PS-TKA. PS-TKA demonstrated a significantly greater range of AP translation than MP-TKA during high flexion ( p = 0.0002). Both groups showed a significantly greater range of lateral compartment posterior translation with medial pivot rotation. The contact points of PS-TKA were located significantly more posterior than MP-TKA in both medial (10°-100°) and lateral (5°-40°, 55°-100°) compartments ( p < 0.0500). MP-TKA had a significantly larger contact area in the medial compartment than in the lateral compartment. In contrast, no significant differences were observed in PS-TKA. The present study revealed no significant differences in clinical outcomes between the MP and PS groups. The PS-TKA demonstrated significantly more posterior translations than MP-TKA at high flexion. The contact points are located more posteriorly in PS-TKA compared with MP-TKA. A larger contact area and medial pivot pattern during high flexion in MP-TKA indicated that MP-TKA provides enhanced medial pivot rotation., Competing Interests: Tsung-Yuan Tsai has received funding from Microport Orthopedics Inc.

Background: Although metal-backed tibial component (MB) is biomechanically superior to all-polyethylene (AP) implants in fixed-bearing unicompartmental knee arthroplasty (UKA), recent studies have shown comparable functional outcomes between the two. However, no study has examined this comparison in obese patients (BMI ≥ 30 kg/m 2 ). We investigated whether functional outcomes between the two implants differ among obese patients, and whether the extent of obesity influences these outcomes., Patients and Methods: Four hundred twenty-two UKA implants from 347 obese patients were reviewed retrospectively. Patients were assessed using the Knee Society Knee Score (KSKS) and Function Score (KSFS), the original Oxford Knee Score (OKS), and SF-36 Physical Component Summary (PCS) and Mental Component Summary (MCS). Minimal clinically important difference (MCID) attainment was recorded. Patients' fulfillment of expectations and satisfaction with the surgery outcome was also graded. Patients were further divided into lower obesity (BMI 30-34.9 kg/m 2 ) and higher obesity (BMI ≥ 35 kg/m 2 ) to examine effect modification., Results: There were no differences in functional outcomes and quality-of-life scores, MCID attainment of functional scores, as well as satisfaction and expectation fulfillment between AP and MB. Among higher obesity patients, AP was associated with a poorer KSKS (p = 0.031) and lower proportion of satisfaction fulfillment (p = 0.041) 2 years postoperatively compared to MB., Conclusion: We found no differences in functional and quality-of-life outcomes between fixed-bearing AP and MB tibial components among obese patients who underwent UKA. However, among higher obesity patients (BMI ≥ 35 kg/m 2 ), patients with AP tibial component were associated with lower KSKS score and a lower proportion of attaining satisfaction fulfillment 2 years postoperatively., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study examines the relationship between socioeconomic status, comorbidities, and clinical outcomes of hip fracture patients. Lower socioeconomic status is not only associated with poorer comorbidities but is also independently impacting surgical access and outcomes. This can be considered a "double setback" in the management of hip fractures., Purpose: The effect of socioeconomic status on hip fracture outcomes remains controversial. We examine the relationship between SES and patient comorbidity, care access, and clinical outcomes of surgically managed hip fracture patients., Methods: Using healthcare payor status as a surrogate for SES, patients operated for fragility hip fractures between 2013 and 2016 were dichotomised based on payor status, namely private healthcare (PRIV) versus subsidised healthcare (SUB). PRIV patients were compared with SUB patients in terms of demographic data, ASA scores, co-morbidity burden (Charlson comorbidity index, CCI), time to surgery, length of acute hospitalisation, and 90-day readmission rates., Results: A total of 145 patients in group PRIV and 1146 patients in group SUB were included. SUB patients had a higher mean Charlson Co-morbidity Index (CCI) (p = 0.01), a longer length of hospitalisation (p = 0.001), an increased delay in surgery (p = 0.005), and higher 90-day readmission rates (p = 0.013). Lower SES (p = 0.01), older age (p = 0.01), higher CCI (p &lt; 0.01), and a higher American Society of Anaesthesiologists score (ASA) (p = 0.03) were predictive of time to surgery. Lower SES (p = 0.02) and higher CCI (p &lt; 0.001) were predictive of the length of hospitalisation. Lower SES (p = 0.04) and higher CCI (p &lt; 0.001) were predictive of 90-day readmission rates., Conclusions: Low SES is associated with higher CCI in surgically treated hip fracture patients. However, it is independently associated with slower access to surgery, a longer hospital stay, and higher readmission rates. Hence, lower SES, with its associated higher CCI and independent impact on surgical access and outcomes, can be considered a "double setback" in the management of fragility hip fractures., (© 2022. International Osteoporosis Foundation and Bone Health and Osteoporosis Foundation.)

Aims: Despite the increasing prevalence of mental health disorders in revision arthroplasty patients, the impact of preoperative mental distress on functional outcomes after revision total hip arthroplasty (rTHA) remains unclear. Our study aims to investigate the impact of preoperative mental distress on functional outcomes after rTHA., Methods: Prospectively collected data of 84 rTHAs was extracted from a single institution's joint replacement registry. Preoperative Short Form-36 (SF-36) mental component summary (MCS) was used to dichotomize patients to those who were distressed (MCS <50) and non-distressed (MCS ≥50). Multivariable analysis was used to analyze the impact of preoperative mental distress on various outcomes such as the SF-36 physical component summary (PCS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Oxford Hip Score (OHS), patient satisfaction and expectation fulfilment at 6 months and 2 years postoperatively., Results: Compared to non-distressed patients, patients with preoperative mental distress had poorer improvements in PCS (+11.4 vs + 16.9, p = 0.007) and lower rates of minimal clinically important difference (MCID) attainment (55.2% vs 73.0%, p = 0.026) at 2 years postoperatively. However, there were no significant differences in improvements for WOMAC and OHS (p > 0.05). Despite experiencing greater absolute improvements in MCS (+12.1 vs -2.1, p < 0.001) and higher MCID attainment rates (65.5% vs 24.3%, p = 0.005) at 2 years, preoperatively distressed patients had lower MCS levels compared to their non-distressed counterparts at all time points (p-value<0.05). There were no significant differences in patient satisfaction (p = 0.509) or expectation fulfilment (p-value = 0.342) at 2 years postoperatively., Conclusion: Revision THA led to substantial mental health improvements in patients with preoperative mental distress. Despite this, preoperative mental distress was associated with poorer physical improvements after surgery., Competing Interests: The authors have no relevant financial or non-financial interests to disclose., (© 2022 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Purpose: There has been a paucity of literature evaluating the role of mediolateral femoral component position (FCP) in medial unicompartmental arthroplasty (UKA). Hence, the aim of this study is to evaluate whether the mediolateral FCP in UKA will affect the 10-year clinical outcomes and quality of life of patients who underwent medial UKA., Methods: Data of 262 patients who underwent medial UKA were analyzed. All patients were assessed at 6 months, 2 years and 10 years using the Knee Society Function Score, Knee Society Knee Score, Oxford Knee Score, Short-Form 36 Physical/Mental Component Scores and postoperative satisfaction. The mediolateral FCP on postoperative radiographs was measured by independent assessors using the Picture Archiving and Communication Systems. 144 patients were distributed into group C (center), 98 into group M (medial) and 20 into group L (lateral) according to FCP, and one-way ANOVA was used to compare the functional outcomes of the three groups., Results: No statistical differences were found between the three groups in terms of 10-year clinical outcomes, quality of life, satisfaction rates and revision rates., Conclusion: Differences in mediolateral FCP did not result in significant difference in 10-year postoperative clinical outcomes for patients who underwent fixed-bearing medial UKAs., Level of Evidence: Retrospective study, Level III., (© 2021. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Background: Current literature lacks consensus regarding the impact of obesity on clinical outcomes of total hip arthroplasty (THA). The variability of results may reflect the lack of minimal clinically important difference (MCID) analysis, which helps to standardise the interpretation of patient-reported outcome measures (PROMs). We compared the PROMs, patient satisfaction and survivorship between obese and non-obese patients after THA., Methods: Prospectively collected registry data of 192 obese patients and 192 propensity score-matched controls who underwent primary THA at a single institution were reviewed. Clinical outcomes and satisfaction rates were assessed at 6 months and 2 years. Reoperations for surgical complications and revision rates were analysed., Results: Obese patients had a significantly poorer Oxford Hip Score (OHS) at 6 months and WOMAC-Function at 2 years. However, there was no difference in overall WOMAC, WOMAC-Pain, WOMAC-stiffness, SF-36 mental and physical component summary (PCS). A similar proportion of patients in each group achieved the MCID for OHS, WOMAC and SF-36 PCS. At 2 years, 90.3% of obese patients and 91.7% of controls were satisfied ( p  = 0.755). At a mean follow-up of 9 years, there were 5 reoperations (2.6%) for surgical complications in the obese group and 1 (0.5%) in the control group; whereas 12 revisions (6.3%) were recorded in the obese group and 3 (1.6%) in the control group ( p  = 0.021)., Conclusions: Despite a higher revision rate, obese patients undergoing THA may experience a similar level of clinical meaningful improvement and satisfaction as their non-obese counterparts. This study provides valuable prognostic information for obese patients and guides preoperative counselling.

Background: No previous study has evaluated the MCID for revision total knee arthroplasty (TKA). This study aimed to identify the MCID for the Knee Society Score (KSS), for revision TKA., Methods: Prospectively collected data from 270 patients who underwent revision TKA at a single institution was analysed. Clinical assessment was performed preoperatively, at 6 months and 2 years using Knee Society Function Score (KSFS) and Knee (KSKS) Scores, and Oxford Knee Score (OKS). MCID was evaluated with a three-pronged methodology, using (1) anchor-based method with linear regression, (2) anchor-based method with receiver operating characteristic (ROC) and area under curve (AUC), (3) distribution-based method with standard deviation (SD). The anchors used were improvement in OKS ≥ 5, patient satisfaction, and implant survivorship following revision TKA., Results: The cohort comprised 70% females, with mean age of 69.0 years, that underwent unilateral revision TKA. The MCID determined by anchor-based linear regression method using OKS was 6.3 for KSFS, and 6.6 for KSKS. The MCID determined by anchor-based ROC was between 15 and 20 for KSFS (AUC: satisfaction = 71.8%, survivorship = 61.4%) and between 33 and 34 for KSKS (AUC: satisfaction = 76.3%, survivorship = 67.1%). The MCID determined by distribution-based method of 0.5 SD was 11.7 for KSFS and 11.9 for KSKS., Conclusion: The MCID of 6.3 points for KSFS, and 6.6 points for KSKS, is a useful benchmark for future studies looking to compare revision against primary TKA outcomes. Clinically, the MCID between 15 and 20 for KSFS and between 33 and 34 for KSKS is a powerful tool for discriminating patients with successful outcomes after revision TKA. Implant survivorship is an objective and naturally dichotomous outcome measure that complements the subjective measure of patient satisfaction, which future MCID studies could consider utilizing as anchors in ROC., Level of Evidence: II., (© 2021. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Purpose: To evaluate the relationship between posterior tibial slope (PTS), posterior condylar offset (PCO), femoral sagittal angle (FSA) on clinical outcomes, and propose optimal sagittal plane alignments for unicompartmental knee arthroplasty (UKA)., Methods: Prospectively collected data of 265 medial UKA was analysed. PTS, PCO, FSA were measured on preoperative and postoperative lateral radiographs. Clinical assessment was done at 6-month, 2-year and 10-year using Oxford Knee Score, Knee Society Knee and Function scores, Short Form-36, range of motion (ROM), fulfilment of satisfaction and expectations. Implant survivorship was noted at mean 15-year. Kendall rank correlation test evaluated correlations of sagittal parameters against clinical outcomes. Multivariable linear regression evaluated predictors of postoperative ROM. Effect plots and interaction plots were used to identify angles with the best outcomes. (p < 0.05) was the threshold for statistical significance., Results: There were significant correlations between PTS, PCO and FSA. Younger age, lower BMI, implant type, greater preoperative flexion, steeper PTS and preservation of PCO were significant predictors of greater postoperative flexion. There were significant interaction effects between PTS and PCO. Effect plots demonstrate a PTS between 2° to 8° and restoration of PCO within 1.5 mm of native values are optimal for better postoperative flexion. Interaction plot reveals that it is preferable to reduce PCO by 1.0 mm when PTS is 2° and restore PCO at 0 mm when PTS is 8°., Conclusion: UKA surgeons and future studies should be mindful of the relationship between PTS, PCO and FSA, and avoid considering them in isolation. When deciding on the method of balancing component gaps in UKA, surgeons should rely on the PTS. Decrease the posterior condylar cut when PTS is steep, and increase the posterior condylar cut when PTS is shallow. The acceptable range for PTS is between 2° to 8° and PCO should be restored to 1.5 mm of native values., Level of Evidence: II., (© 2021. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Study Design: This was a retrospective review of prospectively collected registry data., Objective: The objective of this study was to investigate the effect of smoking on 2 years postoperative functional outcomes, satisfaction, and radiologic fusion in nondiabetic patients undergoing minimally invasive transforaminal lumbar interbody fusion (TLIF) for degenerative spine conditions., Summary of Background Data: There is conflicting data on the effect of smoking on long-term functional outcomes following lumbar fusion. Moreover, there remains a paucity of literature on the influence of smoking within the field of minimally invasive spine surgery., Methods: Prospectively collected registry data of nondiabetic patients who underwent primary single-level minimally invasive TLIF in a single institution was reviewed. Patients were stratified based on smoking history. All patients were assessed preoperatively and postoperatively using the Numerical Pain Rating Scale for back pain and leg pain, Oswestry Disability Index, Short-Form 36 Physical and Mental Component Scores. Satisfaction was assessed using the North American Spine Society questionnaire. Radiographic fusion rates were compared., Results: In total, 187 patients were included, of which 162 were nonsmokers, and 25 had a positive smoking history. In our multivariate analysis, smoking history was insignificant in predicting for minimal clinically important difference attainment rates in Physical Component Score and fusion grading outcomes. However, in terms of satisfaction score, positive smoking history remained a significant predictor (odds ratio=4.7, 95% confidence interval: 1.10-20.09, P=0.036)., Conclusions: Nondiabetic patients with a positive smoking history had lower satisfaction scores but comparable functional outcomes and radiologic fusion 2 years after single-level TLIF. Thorough preoperative counseling and smoking cessation advice may help to improve patient satisfaction following minimally invasive spine surgery., Level of Evidence: Level III-nonrandomized cohort study., Competing Interests: The authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Large-scale quarantine facilities staffed with non-healthcare workers (NHCW) were instrumental in preventing community spread of COVID-19 (coronavirus disease of 2019). The objective of this study was to determine the effectiveness of a newly developed procedural skills training framework in ensuring personal protective equipment (PPE) compliance of PPE-naïve NHCWs., Methods: We developed a PPE procedural skills training framework for NHCWs using the Learn, See, Practice, Prove, Do, and Maintain (LSPPDM) framework and international guidelines on PPE for healthcare workers. The NHCWs underwent PPE training using this framework, conducted by a team of Infection Prevention nurses, prior to being stationed within the CCF. Effectiveness of the LSPPDM PPE training framework was assessed using: 1) competency assessment scores for NHCWs, 2) PPE compliance rates from daily audit findings, and, 3) healthcare-associated COVID-19 infection rates of NHCWs., Results: A total of 883 NHCWs had completed the PPE training and demonstrated competency in PPE compliance, fulfilling 100% of the checklist requirements. Mean PPE compliance of all NHCWs during the 11-week study period was noted to be >96%. The post-implementation improvement was statistically significant when the compliance was expressed in 3-days blocks) and in bed management staff (P = < 0.05). None of the 883 NHCWs who underwent PPE training via the LSPPDM framework were diagnosed with healthcare-associated COVID-19 infection., Conclusion: An evidence-based skills training framework is effective in PPE training of large numbers of NHCWs, resulting in high compliance of appropriate PPE use and prevention of healthcare-associated COVID-19 infection., (Copyright © 2021 Australasian College for Infection Prevention and Control. Published by Elsevier B.V. All rights reserved.)

Background: The factors that affect return to work (RTW) after anterior cervical discectomy and fusion (ACDF) for degenerative cervical myelopathy (DCM) remain unclear, especially in a non-Workers' Compensation setting. We aimed to (1) identify factors that influence RTW in patients undergoing ACDF (2) determine if early RTW plays a role in functional outcomes, quality of life, and satisfaction., Methods: Prospectively collected data of 103 working adults who underwent primary ACDF for DCM were retrospectively reviewed. Patients were stratified into 2 groups: early RTW (≤60 days, n = 42) and late RTW (>60 days, n = 61)., Results: The mean time taken to RTW was 34.7 and 134.9 days in the early and late RTW groups, respectively ( P < 0.001). The early RTW group had significantly better preoperative Japan Orthopaedic Association (JOA) score and Neck Disability Index (NDI) ( P < 0.05) and showed a trend toward higher 36-Item Short Form Physical Component Summary (PCS) ( P = 0.071). The early RTW group also had significantly better postoperative JOA, NDI, and PCS at 6 months and less arm pain along with a trend toward better NDI at 2 years ( P = 0.055). However, there was no difference in the change in outcome scores and a similar proportion in each group attained the minimal clinically important difference for each metric. At 2 years, 85.7% and 77.0% were satisfied in the early and late RTW groups, respectively ( P = 0.275)., Conclusions: While working adults that RTW later tend to have poorer function preoperatively and up to 2 years postoperatively, surgeons may reassure them that they will likely experience the same degree of clinical improvement and level of satisfaction after ACDF., Level of Evidence: Level 3, therapeutic study., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2021 ISASS. To see more or order reprints or permissions, see http://ijssurgery.com.)

Background: There is currently no existing consensus regarding timing of knee arthroplasty. This study aimed to develop a weighted scoring system from patient-reported outcome measures (PROMs) to guide timing of knee arthroplasty based on preoperative severity and long-term effectiveness., Methods: Prospectively collected data of 766 total knee arthroplasties (TKAs) and 382 unicompartmental knee arthroplasties (UKAs) at a single institution were analyzed. PROMs were assessed preoperatively and at 10 years using the Knee Society Score (KSS), Oxford Knee Score (OKS), and Short Form-36 physical component score (SF-36 PCS). Receiver operating characteristic analysis identified thresholds where preoperative PROMs predicted 10-year clinically meaningful improvements (minimal clinically important difference [MCID]). Threshold weights were assigned to PROMs based on their ability to predict MCID in isolation or in combination., Results: Poorer baseline PROMs predicted 10-year MCID attainments. The threshold of 49.5 points for the KSS, 30.5 points for the OKS, and 40.7 points for the SF-36 PCS and 55.5 points for the KSS, 33.5 points for the OKS, and 40.5 points for the SF-36 PCS was weighted 1 point for predicting MCID in 1 PROM for TKA and UKA, respectively. The threshold of 33.4 and 33.9 points for the SF-36 PCS was weighted 2 points for predicting MCID in 2 PROMs, whereas 29.3 and 31.3 points for the SF-36 PCS were weighted 3 points for predicting MCID in 3 PROMs for TKA and UKA, respectively. The sum of weighted components from 0 (lowest) to 5 (highest) represented likelihood for long-term benefits at 10 years., Conclusion: This scoring system is a useful clinical adjunct for deciding timing of knee arthroplasty and prioritizing patients in institutions with long waitlists., Level of Evidence: II., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Comorbidity and hip fracture independently increased mortality risk for 9 years in both sexes, with a significant additive interaction in the first year among women and through 6 years among men., Introduction: Hip fracture is associated with a persistently elevated mortality risk, but it is unknown whether the elevated risk is due to the fracture or to pre-fracture comorbidity., Methods: In a population-based study in Singapore with 9 years of follow-up, patients age > 50 with first hip fracture from 2008 to 2017 were pair-matched to a cohort without hip fracture by age, sex, ethnicity, and pre-fracture Charlson Comorbidity Index (CCI). We investigated additive interaction using the relative excess risk due to interaction (RERI) and multiplicative interaction using the ratio of relative risks., Results: Twenty-two thousand five hundred ninety of 22,826 patients with a first hip fracture in 2008-2017 were successfully matched. Hip fracture and comorbidity independently increased mortality risk for 9 years in both sexes. After adjustment for comorbidity, excess mortality risk continued to persist for 9 years post-fracture in both men and women. Women with a hip fracture and pre-fracture CCI > 4 had a higher relative risk (RR) of mortality at 9 years of 3.29 [95% confidence interval (CI) 3.01, 3.59] than those without comorbidity (RR 1.51, 95%CI 1.36, 1.68) compared to the referent without hip fracture or comorbidity. An additive interaction between hip fracture and pre-fracture CCI > 4 was observed in the first post-fracture year` [relative excess risk due to interaction (RERI) 1.99, 95%CI 0.97, 3.01]. For men with CCI ≥ 4, the positive additive interaction was observed through 6 years., Conclusions: Excess mortality risks post-fracture are attributable to both the fracture and pre-fracture comorbidity. Early interventions in hip fracture patients with high comorbidity could reduce their excess mortality., (© 2021. International Osteoporosis Foundation and National Osteoporosis Foundation.)

Purpose: This study aims to compare PROM improvements and satisfaction rates between revision (rTHA) and primary total hip arthroplasty (pTHA)., Methods: 84 rTHAs were propensity-score matched to 168 pTHAs using patient demographics and preoperative PROMs. Multiple regression was used to evaluate differences in PROMs, minimal clinically important difference (MCID) attainment and patient satisfaction., Results: Compared to pTHA patients, rTHA patients had poorer MCID attainment for OHS, WOMAC and SF-36 PCS and lower satisfaction rates at 2-years postoperatively (p < 0.05)., Conclusion: Patients undergoing rTHA are likely to have poorer outcomes and should be appropriately counselled to better manage their preoperative expectations., Level of Evidence: Level II., Competing Interests: There are no conflicts of interest., (© 2021 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Artificial intelligence (AI) is altering the world of medicine. Given the rapid advances in technology, computers are now able to learn and improve, imitating humanoid cognitive function. AI applications currently exist in various medical specialties, some of which are already in clinical use. This review presents the potential uses and limitations of AI in arthroplasty to provide a better understanding of the existing technology and future direction of this field.Recent literature demonstrates that the utilization of AI in the field of arthroplasty has the potential to improve patient care through better diagnosis, screening, planning, monitoring, and prediction. The implementation of AI technology will enable arthroplasty surgeons to provide patient-specific management in clinical decision making, preoperative health optimization, resource allocation, decision support, and early intervention. While this technology presents a variety of exciting opportunities, it also has several limitations and challenges that need to be overcome to ensure its safety and effectiveness., (© 2021. The Author(s).)

Background: Minimal clinically important difference (MCID) is crucial for interpreting meaningful improvements in patient-reported outcome measures (PROMs). No previous study has evaluated the MCID for the Oxford Knee Score (OKS) in revision total knee arthroplasty (TKA). This study aimed to propose the OKS MCID for revision TKA., Methods: Prospectively collected data from 191 patients who underwent revision TKA at a single institution was analysed. Clinical assessment was performed preoperatively and at 2 years using OKS and Short-Form 36 Physical Component Score (SF-36 PCS). MCID was evaluated with a three-pronged methodology, using (1) anchor-based method with linear regression, (2) anchor-based method with receiver operating characteristic (ROC) and area under curve (AUC), (3) distribution-based method with standard deviation (SD). The anchors used were improvement in SF-36 PCS ≥ 12, patient satisfaction, and implant survivorship following revision TKA., Results: The MCID determined by anchor-based linear regression method using improvements in SF-36 PCS was 4.9 points. The MCID determined by anchor-based ROC was 10.5 points for satisfaction (AUC = 74.8%) and 13.5 points for implant survivorship (AUC = 73.7%). The MCID determined by distribution-based method of 0.5 SD was 4.7., Conclusion: The proposed MCID for OKS following revision TKA is 4.9 points. Patients who achieve an improvement in OKS of at least 10.5-13.5 points by 2 years are likely to be satisfied with their surgery and not require a subsequent re-revision TKA. Patients undergoing revision TKA should aim for an improvement in OKS of at least 10.5-13.5 points as a target score., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Purpose: The Attune® Knee System provides new instrumentation to achieve symmetric flexion/extension gaps in total knee arthroplasty (TKA). However, there is limited information on the optimal TKA technique using this system. The aim of this randomised controlled trial was to determine which surgical technique results in better postoperative clinical outcomes after TKA using the contemporary Attune ® Knee System: the measured resection or gap balancing technique., Methods: A prospective randomized controlled trial was conducted with 100 patients undergoing TKA using measured resection (n = 50) or gap balancing (n = 50) technique. The measured femoral sizer was used in the measured resection group, while the balanced femoral sizer was used in the gap balancing group. Functional outcomes and quality of life were assessed preoperatively and at 6 months and 2 years post-surgery, using the Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Oxford Knee Score (OKS), the Physical Component Score (PCS) and Mental Component Score (MCS) of Short-Form 36 (SF-36). Using weight-bearing coronal radiographs, the hip-knee-ankle angle (HKA), coronal femoral component angle (CFA), coronal tibial component angle (CTA) and joint line height were also evaluated for each patient., Results: There were no significant differences in the functional scores or the proportion of patients from each group who were satisfied or had their expectations fulfilled at 6 months or 2 years post-surgery. There was also no significant difference in the number of patients who attained minimum clinically important difference (MCID) postoperatively between the groups. Postoperatively, there was no significant difference in the number of HKA outliers between the groups (p = 0.202). The postoperative CFA (p = 0.265) and CTA (p = 0.479) were similar between the groups. There was also no significant difference in the absolute change (p = 0.447) or proportion of outliers (p = 0.611) for joint line height between the groups., Conclusion: Both measured resection and gap balancing techniques resulted in comparable functional and quality of life outcomes up to 2 years post-surgery. Both techniques appear to be equally effective in achieving excellent outcomes with the Attune ® Knee System., Level of Evidence: I., (© 2020. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Background: Debridement, antibiotics and implant retention (DAIR) is the treatment of choice for acute postoperative and acute hematogenous periprosthetic joint infection (PJI). There is limited literature on predictive prognostic factors for DAIR. We aim to report the outcomes of DAIR and investigate the predictive prognostic factors., Methods: We retrospectively reviewed 106 DAIRs. Failure was defined as requiring removal of TKA implants. Predictive factors that may influence success of DAIR treatment such as age, gender, body mass index, ethnicity, American Society of Anesthesiologists score, comorbidities, preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein, symptom duration, time between total knee arthroplasty and DAIR, cultures, rifampicin use, polyethylene liner change, and antibiotic duration were analyzed., Results: The success rate of DAIR was 69.8% (74/106 patients). For successes, mean time from DAIR-to-mortality was longer than failures (61.6 ± 42.7 vs 9.75 ± 9.60 months, P = .0150). Methicillin-susceptible Staphylococcus aureus PJI (odds ratio [OR] 3.64, confidence interval [CI] 1.30-10.2, P = .0140) was a significant predictor for failure of DAIR. Higher preoperative ESR correlated to failure (OR 1.02, CI 1.01-1.04, P = .008). In successes, mean ESR was 75.4 (66.1-84.6), whereas mean ESR in failures was 116 (88.3-143) (P = .011). An ESR > 107.5 predicted failure with a sensitivity of 51.5 and specificity of 85.2. ESR > 107.5 correlated to failure (OR 6.60, CI 2.29-19.0, P < .001). Repeat DAIRs were strongly correlated to failure (OR 5.27, CI 1.99-13.9, P < .01)., Conclusion: DAIR failure is associated with earlier time to mortality. Repeat DAIRs, elevated ESR > 107.5, and S aureus PJI are associated with treatment failure and 2-stage revision is recommended., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Despite the expanding indications for unicompartmental knee arthroplasty (UKA), the classic indication that limits flexion contracture to <5° in fixed bearing UKA excludes most patients with arthritic knees and has not been challenged in modern literature. This study compared the clinical outcomes between patients with severe flexion contracture and controls undergoing UKA., Methods: Eighty seven medial fixed bearing UKAs performed in patients with severe (≥15°) flexion contracture were matched 1:1 with 87 controls without flexion or recurvatum deformity (-5°

Purpose: The aims of this study are to evaluate whether improvements in functional outcome and quality of life are sustainable 10 years after total knee arthroplasty (TKA), and the age cut-off for clinical deterioration in outcomes METHODS: Prospectively collected registry data of 120 consecutive patients who underwent TKA at a tertiary hospital in 2006 was analysed. All patients were assessed at 6 months, 2 years and 10 years using the Knee Society Function Score, Knee Society Knee Score, Oxford Knee Score, Short-Form 36 Physical/Mental Component Scores and postoperative satisfaction. One-way ANOVA was used to compare continuous variables, while Chi-squared test to compare categorical variables. Multivariate logistic regression and receiver operating curve analysis was performed to evaluate the predictive factors associated with deterioration of scores postoperatively., Results: Significant improvements were noted in all functional outcome and quality of life scores at 6 months after TKA. Between 6 months and 2 years, the KSFS and OKS continued to improve but the KSKS, PCS and MCS plateaued. Between 2 and 10 years, there was a deterioration in the KSFS and OKS, whilst KSKS, PCS and MCS were maintained. Increasing age was noted to be a significant risk factor for deterioration of KSFS at 10 years with age ≥ 68 as the cut-off value. 91.7% of patients with KSFS Minimally Clinically Important Difference(MCID) (≥ 7 points) continued to be satisfied after 10 years compared to 100.0% who did not experience KSFS MCID deterioration (p = 0.02)., Conclusion: Patients ≥ 68 years experience deterioration in functional outcomes and quality of life from 2 to 10 years after TKA., Level of Evidence: Retrospective study, Level III., (© 2020. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Background: Patient satisfaction is a unique and important measure of success after total hip arthroplasty (THA). Our study aimed to evaluate the use of machine learning (ML) algorithms to predict patient satisfaction after THA., Methods: Prospectively collected data of 1508 primary THAs performed between 2006 and 2018 were extracted from our joint replacement registry and split into training (80%) and test (20%) sets. Supervised ML algorithms (Random Forest, Extreme Gradient Boosting, Support Vector Machines, Logistic LASSO) were developed with the training set, using patient demographics, comorbidities and preoperative patient reported outcome measures (PROMs) (Short Form-36 [SF-36], physical component summary [PCS] and mental component summary [MCS], Western Ontario and McMaster's Universities Osteoarthritis Index [WOMAC] and Oxford Hip Score [OHS]) to predict patient satisfaction at 2 years postoperatively. Predictive performance was evaluated using the independent test set., Results: Preoperative models demonstrated fair discriminative ability in predicting patient satisfaction, with the LASSO model achieving a maximum AUC of 0.76. Permutation importance revealed that the most important predictors of dissatisfaction were (1) patient's age, (2) preoperative WOMAC, (3) number of comorbidities, (4) preoperative MCS, (5) previous lumbar spine surgery, and (6) low BMI (< 18.5)., Conclusion: Machine learning algorithms demonstrated fair discriminative ability in predicting patient satisfaction after THA. We have identified modifiable and non-modifiable predictors of postoperative satisfaction which could enhance preoperative counselling and improve health optimization prior to THA., (© 2021. The Author(s).)

Introduction: The associated mortality and morbidity in hip fracture patients pose a major healthcare burden for ageing populations worldwide. We aim to analyse how an individual's comorbidity profile based on age-adjusted Charlson Comorbidity Index (CCI) may impact on functional outcomes and 90-day readmission rates after hip fracture surgery., Materials and Methods: Surgically treated hip fracture patients between 2013 and 2016 were followed up for 1-year and assessed using Parker Mobility Score (PMS), EuroQol-5D (EQ-5D) and Physical and Mental Component Scores (PCS and MCS, respectively) of Short Form-36 (SF-36). Statistical analysis was done by categorising 444 patients into three groups based on their CCI: (1) CCI 0-3, (2) CCI 4-5 and (3) CCI ≥ 6., Results: PMS, EQ-5D and SF-36 PCS were significantly different amongst the CCI groups pre-operatively and post-operatively at 3, 6 and 12 months (all P < 0.05), with CCI ≥ 6 predicting for poorer outcomes. In terms of 90-day readmission rates, patients who have been readmitted have poorer outcome scores. Multivariate analysis showed that high CCI scores and 90-day readmission rate both remained independent predictors of worse outcomes for SF-36 PCS, PMS and EQ-5D., Discussion: CCI scores ≥6 predict for higher 90-day readmission rates, poorer quality of life and show poor potential for functional recovery 1-year post-operation in hip fracture patients. 90-day readmission rates are also independently associated with poorer functional outcomes. Peri-operatively, surgical teams should liaise with medical specialists to optimise patients' comorbidities and ensure their comorbidities remain well managed beyond hospital discharge to reduce readmission rates. With earlier identification of patient groups at risk of poorer functional outcomes, more planning can be directed towards appropriate management and subsequent rehabilitation., Conclusion: Further research should focus on development of a stratified, peri-operative multidisciplinary, hip-fracture care pathway treatment regime based on CCI scores to determine its effectiveness in improving functional outcomes., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2021.)

Background: A higher prevalence of mental health conditions has been reported in patients undergoing revision total knee arthroplasty (rTKA). This study investigated the effect of preoperative mental health on patient-reported outcome measures (PROMs) and satisfaction after rTKA., Methods: A total of 245 patients who underwent rTKA in 2004-2018 were identified from our institutional joint registry. The most common indications were aseptic loosening (n = 111), infection (n = 70), and instability (n = 35). 36-item Short-Form health survey (SF-36) mental component summary (MCS) was used to stratify the cohort into: Low-MCS (SF-36 MCS <50; n = 112) and control (SF-36 MCS ≥50; n = 133) groups. Knee Society score, Oxford knee score, SF-36 physical score, and a satisfaction questionnaire were used to compare the low-MCS and control at 6 months and 2 years., Results: All PROMs were poorer in the low-MCS group at 6 months and 2 years. However, both groups demonstrated a comparable improvement in each PROM and a similar proportion attained the minimal clinically important difference. Fewer patients in the low-MCS group were satisfied at 2 years (72.2% vs 84.5%, P = .045). Lower preoperative SF-36 MCS was independently associated with increased odds of dissatisfaction (OR 1.037, 95% CI 1.004-1.070, P = .027). Although the change in SF-36 MCS was greater in the low-MCS group, the final value remained lower at 2 years., Conclusion: While patients with poor mental health had inferior PROMs preoperatively and postoperatively, a similar percentage experienced a clinically meaningful improvement at 2 years. Perioperative optimization of psychological factors should still be emphasized as these patients were at a higher risk of dissatisfaction after rTKA., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: There are few studies investigating the effects of acute postoperative pain on functional outcomes after total knee arthroplasty (TKA). The aims of this study are to identify perioperative factors associated with increased early postoperative pain and investigate the effects of acute postoperative day 1 and 2 pain on outcomes at 6 months and 2 years post-TKA., Methods: 1041 unilateral TKA patients were included in this retrospective cohort study. Patients were categorized into minor (visual analog scale: VAS <5) and major (VAS ≥5) pain groups based on postoperative day 1/2 VAS scores. Patients were assessed preoperatively, at 6 months and 2 years using Knee Society Knee Score and Function Scores (KSFS), Oxford Knee Score (OKS), SF-36 physical and mental component score (SF-36 PCS), expectation and satisfaction scores. Perioperative variables including age, gender, race, body mass index, American Society of Anesthesiologist status, type of anesthesia, and presence of caregiver were analyzed as predictors of postoperative acute pain. Wilcoxon two-sample test was used to analyze outcomes significantly associated with "major pain." Multiple logistic regression was used to identify predictors of "major pain.", Results: Patients with "minor pain" had significantly better KSFS, Knee Society Knee Score, OKS, and SF-36 PCS scores at 6 months and significantly better KSFS, OKS, SF-36 PCS, and satisfaction at 2 years (P < .05). A significantly higher percentage of patients with "minor pain" met the minimal clinically important difference for SF-36 PCS at 6 months and KSFS at 2 years (P < .05). Women, Indian/Malay race, higher BMI, and use of general over regional anesthesia were independent predictors of getting "major pain" (P < .05)., Conclusion: Patients should be counseled about risk factors of postoperative pain to manage preoperative expectations of surgery. Patients should be managed adequately using multimodal pain protocols to improve subsequent functional outcomes while avoiding unnecessary opioid use., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Parkinson's disease (PD) may negatively influence the rehabilitative course after total knee arthroplasty (TKA). However, functional outcomes in this select group remain poorly defined. We compared complication, mortality and revision rates, as well as patient-reported outcomes, and satisfaction between patients with PD and controls after TKA., Methods: Patients with PD who underwent primary unilateral TKA were identified and matched 1:1 with a control group using propensity scores adjusting for age, sex, body mass index, Charlson Comorbidity Index, baseline range of motion, Knee Society Knee Score, Knee Society Function Score, Oxford Knee Score, and 36-item Short-Form Health Survey Mental and Physical Component Summary. Functional outcomes and patient satisfaction were assessed at 6 months and 2 years. Complications, survivorship, and all-cause mortality were analyzed., Results: In total, 114 patients were included. Majority of PD patients had Hoehn and Yahr stage 1 or 2 disease. Overall complication rate was 26.3% in the PD group and 10.5% in the control group (P = .030). There was no difference in transfusions, length of stay, and discharge to rehabilitation or readmissions. Patients with PD had more flexion contractures, poorer Knee Society Function Score and Oxford Knee Score at 2 years, and poorer 36-item Short-Form Health Survey Physical Component Summary at 6 months. 80.4% of patients with PD were satisfied compared with 85.5% of controls (P = .476). At follow-up of 8.5 ± 2.7 years, one TKA was revised in each group. All-cause mortality was higher in the PD group (15.8% vs 5.3%, P = .067)., Conclusion: Although patients with PD had relatively poorer knee function and quality of life, these patients still experienced significant functional gains compared with their preoperative status, and high satisfaction was achieved., Level of Evidence: III., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Previous studies evaluating weight changes following total knee arthroplasty (TKA) were performed on heterogenous cohorts. However, no study has evaluated weight changes in a cohort of simultaneous-bilateral TKA (SB-TKA) patients. This study aimed to evaluate the prevalence of patients who lost or gained weight, determine if postoperative weight change influences functional outcome, and identify predictors of weight change after SB-TKA., Methods: Prospectively collected registry data of 560 patients who underwent SB-TKA were reviewed. Patients were assessed preoperatively, at 6 months, and 2 years using the Knee Society Score, Oxford Knee Score, Short-Form 36, and range of motion. Change in body mass index (BMI) >5% was used to categorize patients into 3 groups: lost, maintained, or gained weight. Analysis of variance, Kruskal-Wallis test, and chi-squared test were used to compare functional outcomes between groups. Multivariable logistic regression evaluated predictors for postoperative weight changes., Results: At 2 years, 59% of patients maintained weight, 28% of patients gained weight, and 13% of patients lost weight. All groups experienced similar improvements in functional outcomes, rates of minimal clinically important difference attainment, and patient satisfaction (P > .05). Older patients were more likely to gain weight (P < .05). Patients with higher preoperative BMI were more likely to gain weight (P < .05) and less likely to lose weight (P < .05). Patients with greater preoperative comorbidities were less likely to lose weight (P < .05)., Conclusion: Up to 41% of patients experience significant weight changes after SB-TKA. Older patients with higher preoperative BMI were more likely to gain weight, while higher preoperative BMI with more comorbidities were less likely to lose weight following SB-TKA; however, postoperative weight changes do not appear to affect functional outcomes., Level of Evidence: III, therapeutic study., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Some studies have suggested that women have poorer short-term outcomes after unicompartmental knee arthroplasty (UKA) due to a higher incidence of implant overhang. This study aimed to compare patient-reported outcome measures (PROMs) between men and women after UKA at a minimum follow-up of 10 years., Methods: Patients who underwent medial fixed-bearing UKA by two arthroplasty surgeons were identified from an institutional joint registry. Men and women were matched for age, body mass index, Charlson Comorbidity Index, American Society of Anesthesiologists class, range-of-motion and baseline PROMs using propensity scores. PROMs were compared at 2 and 10 years. Patients also completed a satisfaction questionnaire during these visits. Radiographic outliers were defined as > 2 mm of overhang., Results: A total of 128 patients were included. There was no difference in complications, length of stay or readmissions. Women had poorer Knee Society functional scores, Short-Form 36 physical and mental component scores (SF-36 MCS) at 2 years. No difference in PROMs was found at 10 years, except for poorer SF-36 MCS in women (P = 0.041). At 10 years, 96% of women and 92% of men were satisfied (P = 0.243). Fifteen-year survivorship free from any revision was 96% in each group. There were more medial-tibial outliers in women (9%) compared with men (5%) (P = 0.018). However, no association between outliers and outcomes or survivorship was found on multivariate analyses., Conclusion: There was nodifference in clinical outcomes between men and women undergoing UKA at a minimum follow-up of 10 years. While women had a higher incidence of medial tibial overhang, this was not associated with long-term outcomes or survivorship., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: While in vitro wear simulation of unicompartmental knee arthroplasty (UKA) showed outstanding long-term wear performance, studies reported that polyethylene (PE) wear was responsible for 12% fixed-bearing (FB) UKA failure. This paper aimed to quantify the in vivo 6-degrees-of-freedom (6-DOF) knee kinematics and contact positions of FB UKA during daily activities and compare with the previous results of in vitro wear simulator., Methods: Fourteen patients following unilateral medial FB UKA received a CT scan and dual fluoroscopic imaging during level walking, single-leg deep lunge, and sit-to-stand motion for evaluating in vivo 6-DOF FB UKA kinematics. The closest point between surface models of the femoral condyle and PE insert was determined to locate the medial compartmental articular contact positions, which were normalized relative to the PE insert length. The in vivo contact area was compared with the in vitro wear region in previous simulator studies., Results: The in vivo contact positions during daily activities were more anterior than those in the previous in vitro wear simulator studies ( p < 0.001). Significant differences in the femoral anteroposterior translation and tibial internal rotation during the stance phase were observed and compared with those in lunge and sit-to-stand motions ( p < 0.05). The in vivo contact position located anteriorly and medially by 5.2 ± 2.7 and 1.8 ± 1.6 mm on average for the stance phase, 1.0 ± 2.4 and 0.9 ± 1.5 mm for the lunge, and 2.1 ± 3.3 and 1.4 ± 1.4 mm for sit-to-stand motion. The in vivo contact position was in the more anterior part during the stance phase ( p < 0.05)., Conclusion: The current study revealed that the contact position of FB UKA was located anteriorly and medially on the PE insert during in vivo weight-bearing activities and different from previous findings of the in vitro wear simulator. We should take in vivo 6-DOF knee kinematics and contact patterns of FB UKA into account to reproduce realistic wear performance for in vitro wear simulator and to improve implant design., Competing Interests: QW got research support from Stryker Corp., United States. T-YT got research support from MicroPort Co., Ltd., China. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Dai, Zheng, Zou, Zhu, Liow, Tsai and Wang.)

Study Design: This was a retrospective review of prospectively collected data., Objectives: Few studies have described the relationship between mental health and patient-reported outcome measures (PROMs) after minimally invasive spine surgery. Prior studies on open surgery included small cohorts with short follow-ups., Methods: Patients undergoing primary minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for degenerative pathology were retrospectively reviewed and stratified by Short Form (SF-36) Mental Component Summary (MCS): low MCS (<50, n = 436) versus high MCS (≥50, n = 363). PROMs assessed were back pain, leg pain, North American Spine Society Neurogenic Symptoms, Oswestry Disability Index, SF-36 Physical Component Summary, and MCS. Satisfaction, expectation fulfilment, and return to work (RTW) rates also were recorded at 1 month, 3 months, 6 months, and 2 years., Results: Preoperative MCS was 39.4 ± 8.6 and 58.5 ± 5.4 in the low and high MCS groups, respectively ( P < .001). The low MCS group had significantly poorer preoperative PROMs and longer lengths of stay. Despite this, both groups achieved comparable PROMs from 3 months onward. The mean MCS was no longer significantly different by 3 months ( P = .353). The low MCS group had poorer satisfaction ( P = .022) and expectation fulfilment ( P = .020) at final follow-up. RTW rates were initially lower in the low MCS group up to 3 months ( P = .034), but the rates converged from 6 months onward., Conclusions: Despite poorer PROMs preoperatively, patients with poor baseline mental health still achieved comparable results from 3 months up to 2 years after MIS-TLIF. Preoperative optimization of mental health should still be pursued to improve satisfaction and prevent delayed RTW after surgery.

Background: The aim of this study is to compare the long-term functional outcome and quality of life between total knee arthroplasty (TKA) and fixed-bearing unicompartmental knee arthroplasty (UKA) for the treatment of isolated medial compartment osteoarthritis., Methods: Between 2000 and 2008, a total of 218 patients underwent primary UKA at our tertiary hospital. A TKA group was matched through 1:1 propensity score matching and adjusted for age, gender, body mass index, preoperative knee flexion, and function scores. All patients had medial compartment osteoarthritis. The patients were assessed with the range of motion, Knee Society Knee Score and Knee Society Function Score, Oxford Knee Score, Short Form-36 physical component score (PCS) and mental component score preoperatively, at 6 months, 2 years, and 10 years. Patients' satisfaction, expectation fulfillment, and minimal clinically important difference were analyzed., Results: There were no differences in baseline characteristics between groups after propensity score matching (P > .05). UKA had greater knee flexion at all time points. Although the Knee Society Function Score was superior in UKA by 5.5, 3, and 4.3 points at 6 months, 2 years, and 10 years, respectively (P < .001), these differences did not exceed the minimal clinically important difference (Knee Society Knee Score 6.1). There were no significant differences in the Oxford Knee Score and Short Form-36 physical component score/mental component score. At 10 years, similar proportions of UKA and TKA were satisfied (90.8% vs 89.9%, P = .44) and had expectation fulfillment (89.4% vs 88.5%, P = .46). Between 2 and 10 years, all function scores deteriorated significantly for both groups (P < .01)., Conclusion: UKA and TKA are excellent treatment modalities for isolated medial compartment osteoarthritis, with similar functional outcomes, quality of life, and satisfaction at 10 years., (Copyright © 2020 Elsevier Inc. All rights reserved.)