POST-OPERATIVE SPORT PARTICIPATION AND SATISFACTION WITH RETURN TO ACTIVITY AFTER MATRIX-INDUCED AUTOLOGOUS CHONDROCYTE IMPLANTATION IN THE KNEE.

BACKGROUND: Returning to a satisfactory activity level is expected by patients after cartilage repair, and may define overall surgical success. PURPOSE: To investigate: 1) the level and improvement in activity in patients at two years after matrix-induced autologous chondrocyte implantation (MACI), 2) what factors are associated with post-operative (and improvement in) activity level, and 3) whether patients are satisfied with their ability to participate in recreational and/or sporting activities. STUDY DESIGN: Prospective cohort. METHODS: One hundred and fifty patients that underwent MACI were included in this analysis (83 tibiofemoral and 67 patellofemoral). All patients completed the Tegner Activity Scale (TAS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) pre-surgery and at two years (range: 24-26 months) post-surgery, as well as a questionnaire evaluating satisfaction with their ability to return to recreational and sporting activities. RESULTS: The TAS significantly improved (p<0.001) from 2.97 (SD 0.92, range 0-7) to 4.09 (SD 1.49, range 0-9), while the KOOS Sport significantly improved (p<0.0001) from 27.5 (SD 23.1, range 0-95) to 61.1 (SD 27.3, range 0-100). Overall, 88 patients (59%) improved ≥ 1 point on the TAS, while 121 patients (81%) improved ≥ 10 points on the KOOS Sport, previously reported as the minimal detectable change for each. Patient age, duration of symptoms (DOS) and gender were associated with post-operative activity level, though body mass index (BMI), defect size and concomitant procedures were not. Overall, 128 patients (85%) were satisfied with their ability to return to recreational activities, with 99 (66%) satisfied with sport participation. The two-year TAS, and TAS improvement, were significantly associated with satisfaction in performing recreational activities (two-year TAS, rho=-0.42, p<0.0001; TAS improvement, r=-0.33, p<0.0001) and sport participation (two-year TAS, rho=-0.49, p<0.0001; TAS improvement, r=-0.37, p<0.0001). CONCLUSIONS: The TAS and KOOS Sport significantly improved after MACI, though only 59% of patients improved ≥ 1 point on the TAS. Despite this, 85% and 66% of patients were satisfied with their ability to return to recreational activities and participate in sport, respectively. Age, DOS and gender were associated with activity, and overall these findings can be used to provide realistic activity expectations to patients undergoing MACI. LEVEL OF EVIDENCE: Level 3, prospective cohort study.