Factors predictive of outcome 5 years after matrix-induced autologous chondrocyte implantation in the tibiofemoral joint

Background: Matrix-induced autologous chondrocyte implantation (MACI) has become an established technique for the repair of full-thickness chondral defects in the knee. However, little is known about what variables most contribute to postoperative clinical and graft outcomes as well as overall patient satisfaction with the surgery.Purpose: To estimate the improvement in clinical and radiological outcomes and investigate the independent contribution of pertinent preoperative and postoperative patient, chondral defect, injury/surgery history, and rehabilitation factors to clinical and radiological outcomes, as well as patient satisfaction, 5 years after MACI. Study Design: Cohort study; Level of evidence, 3.Methods: This study was undertaken in 104 patients of an eligible 115 patients who were recruited with complete clinical and radiological follow-up at 5 years after MACI to the femoral or tibial condyles. After a review of the literature, a range of preoperative and postoperative variables that had demonstrated an association with postoperative clinical and graft outcomes was selected for investigation. These included age, sex, and body mass index; preoperative 36-item Short Form Health Survey (SF-36) mental component score (MCS) and physical component score (PCS); chondral defect size and location; duration of symptoms and prior surgeries; and postoperative time to full weightbearing gait. The sport and recreation (sport/rec) and knee-related quality of life (QOL) subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS) were used as the patient-reported clinical evaluation tools at 5 years, while high-resolution magnetic resonance imaging (MRI) was used to evaluate graft assessment. An MRI composite score was calculated based on the magnetic resonance observation of cartilage repair tissue score. A patient satisfaction questionnaire was completed by all patients at 5 years. Regression analysis was used to investigate the contribution of these pertinent