Matrix-Assisted Autologous Chondrocyte Transplantation in the Knee: A Systematic Review of Mid- to Long-Term Clinical Outcomes

Background: Matrix-assisted autologous chondrocyte transplantation (MACT) is a surgical treatment option for articular cartilage lesions of the knee joint. Purpose: To investigate mid- to long-term clinical outcomes of MACT in the patellofemoral (PF) and tibiofemoral (TF) joints. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review was performed by searching PubMed, Embase, and the Cochrane Library to find studies evaluating minimum 5-year clinical outcomes of patients undergoing MACT in the knee joint. Search terms used were knee, matrix, and autologous chondrocyte. Patients were evaluated based on treatment failure rates, magnetic resonance imaging, and subjective outcome scores. Study methodology was assessed using the Modified Coleman Methodology Score (MCMS). Results: Ten studies (two level 1, one level 2, one level 3, and six level 4 evidence) were identified that met inclusion and exclusion criteria, for a total of 442 TF patients and 136 PF patients. Treatment failure occurred in 9.7% of all patients, including 4.7% of PF patients and 12.4% of TF patients (P = .037). Weighted averages of subjective outcome scores, including Knee injury and Osteoarthritis Outcome Score, Short Form-36 Health Survey, and Tegner scores, improved from baseline to latest follow-up in both TF and PF patients. The mean MCMS was found to be 57.4, with a standard deviation of 18.5. Conclusion: Patients undergoing MACT in the knee show favorable mid- to long-term clinical outcomes. A significantly higher treatment failure rate was found in patients undergoing MACT in the TF joint compared with the PF joint.