To determine the 5-year outcome of treatment for meniscal tear in osteoarthritis.
We examined 5-year follow-up data from the Meniscal Tear in Osteoarthritis Research trial (METEOR) of physical therapy versus arthroscopic partial meniscectomy. We performed primary intent-to-treat (ITT) and secondary as-treated analyses. The primary outcome measure was the Knee Injury and Osteoarthritis Outcome Score (KOOS) pain scale; total knee replacement (TKR) was a secondary outcome measure. We used piecewise linear mixed models to describe change in KOOS pain. We calculated 5-year cumulative TKR incidence and used a Cox model to estimate hazard ratios (HRs) for TKR, with 95% confidence intervals (95% CIs).
Three hundred fifty-one participants were randomized. In the ITT analysis, the KOOS pain scores were ~46 (scale of 0 [no pain] to 100 [most pain]) at baseline in both groups. Pain scores improved substantially in both groups over the first 3 months, continued to improve through the next 24 months (to ~18 in each group), and were stable at 24-60 months. Results of the as-treated analyses of the KOOS pain score were similar. Twenty-five participants (7.1% [95% CI 4.4-9.8%]) underwent TKR over 5 years. In the ITT model, the HR for TKR was 2.0 (95% CI 0.8-4.9) for subjects randomized to the arthroscopic partial meniscectomy group, compared to those randomized to the physical therapy group. In the as-treated analysis, the HR for TKR was 4.9 (95% CI 1.1-20.9) for subjects ultimately treated with arthroscopic partial meniscectomy, compared to those treated nonoperatively.
Pain improved considerably in both groups over 60 months. While ITT analysis revealed no statistically significant differences following TKR, greater frequency of TKR in those undergoing arthroscopic partial meniscectomy merits further study.