Total knee arthroplasty (TKA) for treatment of osteoarthritis has a a good track record(2). Complications requiring revision surgery however do occur and are associated with higher costs and worse outcomes than (3). As the demand for TKAs is projected to grow exponentially, revision surgeries will correspondingly increase (4) with young adult patients representing a growing proportion (5, 6). There remains a lack of data in the current literature examining the outcomes of knee replacements in terms of risk of revision and re-revisions by specific indication. This study aims to compare the outcomes of revision TKA by indication within a high-volume arthroplasty center. A retrospective observational study of a prospectively gathered database was performed. Our inclusion criteria was all patients who underwent revision TKA with osteoarthritis as the indication for the original procedure. We excluded any first revisions performed for infection. Kaplan-Meier estimates were used to determine the cumulative probability of revision and subsequent re-revision after primary hip replacement for all-cause revision as well as the most encountered indications for revision. Analyses were stratified by age, sex and indication for revision. We also measured the influence of time from first to second revision on the risk of further revision. Regression analysis was performed to determine associated factors influencing revision and re-revision. Over a 20-year period, there were 254 revision TKAs included in the study. The majority of first revisions took place within 5 years of primary surgery: 92.1% survivorship at 5 years (95%CI 87.5–94.8), 89.4% at 10 years (95%CI 85.0–93.1) and 88.1% at 15 years (95%CI 82.1–92.7). Aseptic loosening was the main reason for revision surgery in all age groups (75/254) followed by pain (51/254) and instability (40/254). The top reasons for revision in the 35) (OR 1.16, 95%CI 1.11–1.32) and higher ASA grades (OR 1.06, 95%CI 1.01–1.12). There were no statistically significant differences in the survivorship curves for first and second revisions. Subgroup analyses showed that predictors for revision for aseptic loosening include younger age (OR 1.37, 95%CI 1.26–1.44), increased time from the previous surgery (OR 1.36; 95%CI 1.28–1.45), higher BMI (OR 1.24, 95%CI 1.17–1.33) and higher ASA grades (OR 1.12, 95%CI 1.06–1.22). Predictors for revision for pain are low pre-operative flexion ( This 20-year sample of a high-volume arthroplasty centre provides a highly applicable assessment of indication by revision and re-revision for TKA which lacking in the current literature. Younger patients undergoing joint replacement surgery should be informed that they may be at significantly higher risk of revision and re-revision surgery. This work will contribute to the understanding of these patients' individual risks and emphasizes the importance of optimizing risk factors before proceeding with TKA, particularly with respect to the risks of pain and aseptic loosening.
Howard et al. (Wed,) studied this question.