Purpose: To identify the prognostic factors for 2-year patient-reported outcomes in middle-aged patients with degenerative meniscal tears treated with exercise therapy (ET) or arthroscopic partial meniscectomy (APM).
Methods: One hundred and seven patients, with mean age 49.6 (SD 6.2) years and BMI 25.7 (SD 3.7), were included in this analysis of data from the OMEX trial ( http://www.clinicaltrials.gov NCT01002794). Linear and Poisson regression models were built to explore the associations between potential prognostic factors (patient characteristics, knee function-related and disease-related factors) and 2-year patient-reported outcomes: the Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales Pain, Symptoms, ADL, Sport/Rec, QoL and 5-point Global Rating of Change scales for knee pain (GRC Pain) and function (GRC Function). Analyses were performed for the whole cohort and for the two treatment groups (n = 55 and 52) with adjustments for age, sex, BMI and baseline KOOS.
Results: For the whole cohort, a 1-s better baseline 6-m timed hop test result was associated with 3.1-7.1 points better 2-year scores for all KOOS subscales (95% CIs 1.1-5.2 to 4.1-10.1 points). A 1.61-2.80 s better test was associated with scores equivalent to previously calculated clinical relevant differences for each KOOS subscale. For the groups of patients treated with ET and APM, respectively, 2.09-3.60 s and 0.63-1.99 s better tests were associated with clinical relevant differences. For the whole cohort, a 1-s better test was associated with 26% (95% CI 15-38%) and 22% (95% CI 11-34%) higher possibility for better or much better GRC Pain and Function scores. Patients treated with ET had 17% (95% CI 2-33%) increased possibility for better or much better GRC Pain score, and patients treated with APM had 65% (95% CI 32-108%) and 70% (95% CI 38-109%) increased possibility for better or much better GRC Pain and Function scores.
Conclusions: The 6-m timed hop test result was a significant prognostic factor for 2-year patient-reported outcomes in middle-aged patients with degenerative meniscal tears, especially in those treated with APM.
Level of evidence: II.
Keywords: 6-m timed hop test; Arthroscopic partial meniscectomy; Degenerative meniscal lesions; Degenerative meniscal tears; Exercise therapy; Lower extremity performance; Middle aged; Prognostic factors.