Activity-Related Outcomes of Articular Cartilage Surgery: A Systematic Review

Objective: The purpose of this systematic review was to compare activity-based outcomes after microfracture, autologous chondrocyte implantation (ACI), and osteochondral autograft (OAT). Design: Multiple databases were searched with specific inclusion and exclusion criteria for level III and higher studies with activity outcomes after microfracture, OAT, osteochondral allograft, and ACI. Activity-based outcomes included the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Tegner Score, the Cincinnati Knee scores, the International Knee Documentation Committee (IKDC) subjective knee score, the Marx activity score, and/or the rate of return-to-sport. Results: Twenty studies were included (1,375 patients). Although results were heterogeneous, significant advantages were seen for ACI and OAT as compared with microfracture in Tegner scores at 1 year (ACI vs. microfracture, P = 0.0016), IKDC scores at 2 years (ACI vs microfracture, P = 0.046), Lysholm scores at 1 year (OAT vs microfracture, P = 0.032), and Marx scores at 2 years (OAT vs microfracture, P < 0.001). The only score or time point to favor microfracture was Lysholm score at 1 year (ACI vs microfracture, P = 0.037). No other standardized outcome measures or time points were significantly different. Several studies demonstrated significantly earlier return to competition with microfracture. Overall reoperation rates were similar, but of reoperations, a higher proportion of those following ACI were unplanned with the majority of performed for graft delamination or hypertrophy. Conclusions: ACI and OAT may have some benefits over microfracture, although return-to-sport is fastest following microfracture. Heterogeneity in technique, outcome measures, and patient populations hampers systematic comparison within the current literature.