Five-Year Outcome of Operative and Nonoperative Management of Meniscal Tear in Persons Older Than Forty-Five Years

Abstract

Objective: To determine the 5-year outcome of treatment for meniscal tear in osteoarthritis.

Methods: 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).

Results: 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.

Conclusion: 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.

Figure 1:

Crude KOOS Pain scores with 95% CI for subjects randomized to APM (blue) and randomized to PT (red).

Figure 2:

Piecewise linear mixed model of KOOS Pain scores in subjects randomized to APM (blue) and randomized to PT (red). Slopes are estimated in four time periods: 0–3 months, 3–12 months, 12–24, and 24–60 months.

Figure 3:

KOOS Pain scores are estimated for three groups: those who had TKR, those who dropped out of the study for reasons other than TKR (non-completers); and those who completed the study (completers). The pattern mixture model (PMM) shows the weighted average of the TKR, non-completers, and completer groups. The Non-PMM trace shows the results of the piecewise linear mixed model. The figure demonstrates that the PMM and non-PMM traces are very similar (since only 7% of subjects had TKR). The non-completer and TKR lines are dashed to indicate that the slopes are generated from data obtained before members of these groups left the cohort.

Figures 4a-b:

Kaplan Meier plots of time to TKR in two intention to treat groups (4a): randomized to APM (blue) and randomized to PT (red); and in three as-treated groups (4b): subjects randomized to and receiving APM (blue), randomized to PT and not crossing over (red), and randomized to PT and crossover over to APM (green).

Figures 4a-b:

Kaplan Meier plots of time to TKR in two intention to treat groups (4a): randomized to APM (blue) and randomized to PT (red); and in three as-treated groups (4b): subjects randomized to and receiving APM (blue), randomized to PT and not crossing over (red), and randomized to PT and crossover over to APM (green).