Variation in Patient-Reported Outcomes in Young and Old Patients Up to 4 to 6 Years After Arthroscopic Partial Meniscectomy.

Objective: To assess the variation in changes in patient-reported outcomes 4 to 6 years after arthroscopic partial meniscectomy (APM).

Design: Prospective cohort study.

Setting: Orthopedic departments at public hospitals.

Patients: Patients (n = 447) from the Knee Arthroscopy Cohort Southern Denmark undergoing APM.

Interventions: All patients underwent APM.

Main Outcome Measures: Change in KOOS4 scores from baseline before surgery to ∼5 years (range 4-6 years) after surgery. KOOS4 is the average aggregated score of 4 of 5 of the Knee injury and Osteoarthritis Outcome Score (KOOS) excluding the activities of daily living subscale (minimal clinical important improvement ∼10 points). A mixed linear model adjusted for sex and body mass index was used to assess change from baseline to ∼5-year follow-up. Change in KOOS4 was divided into 5 categories based on change from baseline to ∼5-year follow-up: <0 points, 0 to 9 points, 10 to 19 points, 20 to 29 points, and ≥30 points.

Results: On average, patient-reported outcomes continued to improve from baseline to ∼5-year follow-up (mean KOOS4 change: 26, 95% CI, 24-28). Proportions in the different response groups were <0 points (12%), 0 to 9 points (13%), 10 to 19 points (16%), 20 to 29 points (19%), and ≥30 points (40%), with no difference between younger (≤40 years, n = 75) and older (>40 years, n = 337) patients (P = 0.898).

Conclusions: Patient-reported outcomes on average improved up to ∼5 years after APM; however, large variability was observed. The similar variability in younger and older patients questions the assumption that younger patients with traumatic injuries experience larger benefits from APM.