Aseptic revision total knee arthroplasty outcomes were equivalent to patients' own pre-failure state but inferior to patients without revision.

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.

Defining the minimal clinically important difference for the knee society score following revision total knee arthroplasty.

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.

Posterior condylar offset and posterior tibial slope targets to optimize knee flexion after unicompartmental knee arthroplasty.

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.

The oxford knee score minimal clinically important difference for revision total knee arthroplasty.

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.

Behavioral impact of national health campaigns on healthy lifestyle practices among young adults in Singapore: a cross-sectional study.

BACKGROUND: National health campaigns are often used to improve lifestyle behaviors in the general population. However, evidence specifically in the young adult population is scarce. Given the general deterioration of healthy lifestyle practices from adolescence to young adulthood, it is imperative to study this age group. This study aimed to investigate the behavioral impact of a national health campaign in Singapore on the lifestyle practices of young adults, and whether sex or full-time working and schooling status affected lifestyle practices. METHODS: A total of 594 Singaporean respondents aged 18-39 years old were interviewed via a cross-sectional study in December 2019. Lifestyle practices assessed were diet, exercise, alcohol consumption, current tobacco use, and participation in health screening programs. Other factors investigated included exposure to the national health campaign "War on Diabetes" (WoD), sex, ethnicity, and working/schooling status. Multivariable modified Breslow-Cox proportional hazards models were used to estimate prevalence risk ratios (PRRs) as measures for the associations in this study, after adjusting for potential confounders. RESULTS: Exposure to the WoD campaign had a significant association with meeting dietary recommendations (PRR = 1.6, 95% CI: 1.0-2.5, p = 0.037), participation in screening (PRR = 1.2, 95% CI: 1.0-1.5, p = 0.028), and current tobacco use (PRR = 0.5, 95% CI: 0.3-0.8, p = 0.003). Males were significantly more likely to meet exercise recommendations (PRR = 2.0, 95% CI: 1.5-2.7, p < 0.001), currently use tobacco (PRR = 3.9, 95% CI: 2.2-6.9, p < 0.001), and consume alcohol excessively (PRR = 1.5, 95% CI: 1.0-2.3, p = 0.046), as compared to females. Working young adults were significantly less likely to meet exercise recommendations (PRR = 0.7, 95% CI: 0.5-0.9, p = 0.019) but significantly more likely to be current tobacco users (PRR = 1.8, 95% CI: 1.1-3.1, p = 0.024), as compared to those who were in school. CONCLUSIONS: While this paper affirms that national health campaigns have significant beneficial associations in diet, health screenings and current tobacco use, policymakers should acknowledge that young adults are an age group with different influences that impact their healthy lifestyle habits. Specific interventions that target these subgroups may be required for better health outcomes. Future studies should evaluate other socio-environmental factors that could play a role in modifying the effect of health campaigns among young adults.