Can Baseline MRI Findings Identify Who Responds Better to Early Surgery Versus Exercise and Education in Young Patients With Meniscal Tears? A Subgroup Analysis From the DREAM Trial.

To investigate whether magnetic resonance imaging (MRI) findings modified the outcomes of early surgery compared to exercise and education in young patients with meniscal tears. A secondary effect modifier analysis of a randomized controlled trial. The primary outcome was change from baseline to 12 months in the mean score of 4 Knee injury and Osteoarthritis Outcome Score subscales (KOOS). Three potential MRI-defined effect modifiers were predefined: (1) the type of meniscal tear (simple vs bucket handle or complex), (2) the meniscus affected (medial vs lateral), and (3) the presence of knee effusion/synovitis (yes/no). We used a linear mixed model to investigate the difference in mean change between the treatment groups, stratified by each of the 3 potential effect modifiers, and estimated the interactions. An adjusted effect difference ≥ 10 points (0-100 scale) was considered clinically relevant. Data from all participants (60 in the surgery group and 61 in the exercise group) were analyzed. The mean (SD) age was 29.7 (6.6) years, and 28% were female. A potential effect modification was observed for knee effusion/synovitis, with its presence implying an increase of the effect of early surgery by 11 points on the KOOS ( = .07). Knee effusion/synovitis on MRI potentially modified the treatment effect with a clinically relevant difference in change of the KOOS in patients with effusion/synovitis, favoring early surgery. We found no indication that patients with bucket handle or complex versus simple tears or medial versus lateral tears benefited more from early surgery. .