Is Delayed Weightbearing After Matrix-Associated Autologous Chondrocyte Implantation in the Knee Associated With Better Outcomes? A Systematic Review of Randomized Controlled Trials

Abstract

Background: Proper rehabilitation after matrix-associated autologous chondrocyte implantation (MACI) is essential to restore a patient’s normal function without overloading the repair site. Purpose: To evaluate the current literature to assess clinical outcomes of MACI in the knee based on postoperative rehabilitation protocols, namely, the time to return to full weightbearing (WB). Study Design: Systematic review; Level of evidence, 1. Methods: A systematic review was performed to locate studies of level 1 evidence comparing the outcomes of patients who underwent MACI with a 6-week, 8-week, or 10/11-week time period to return to full WB. Patient-reported outcomes assessed included the Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner activity scale, Short Form Health Survey–36 (SF-36), and visual analog scale (VAS) for pain frequency and severity. Results: Seven studies met the inclusion criteria, including a total of 136 patients (138 lesions) who underwent MACI. Treatment failure had occurred in 0.0% of patients in the 6-week group, 7.5% in the 8-week group, and 8.3% in the 10/11-week group at a mean follow-up of 2.5 years (P =.46). KOOS, SF-36, and VAS scores in each group improved significantly from preoperatively to follow-up (P