Recommendations and Treatment Outcomes for Patellofemoral Articular Cartilage Defects With Autologous Chondrocyte Implantation Prospective Evaluation at Average 4-Year Follow-up

Background: Reported results of autologous chondrocyte implantation for chondral lesions in the patellofemoral joint have been encouraging when combined with realignment procedures. Purpose: The objective of this study was to examine the clinical results of a patient cohort undergoing autologous chondrocyte implantation of the patellofemoral joint and elucidate characteristics associated with successful implantation. Study Design: Case series; Level of evidence, 4. Methods: The cohort included 62 patients who underwent autologous chondrocyte implantation of the PF joint. The mean defect size was 4.2 cm(2) (+/- 1.6). The average age was 31.8 years (range, 15.8-49.4), and the average follow-up was 4 years (range, 2-7). Outcomes were assessed via clinical assessment and established outcome scales, including the Lysholm, International Knee Documentation Committee, Knee Injury and Osteoarthritis Outcome Scale (KOOS; includes the 5 categories of Pain, Symptoms, Activities of Daily Living, Sport, and Quality of Life), Tegner, Cincinnati, and Short Form-12. Results: Mean improvement in the preoperative to postoperative scores was significant for the Lysholm (37-63, P < .001), International Knee Documentation Committee (31-57, P < .001), KOOS Pain (48-71, P < .001), KOOS Symptoms (51-70, P < .001), KOOS Activities of Daily Living (60-80, P < .001), KOOS Sport (25-42, P < .001), KOOS Quality of Life (24-49, P < .001), Short Form-12 Physical (38-41, P < .05), Cincinnati (43-63, P < .005), and Tegner (4-6, P < .05), but not for the Short Form-12 Mental. There was no statistical difference between outcomes in patients with a history of a previous failed cartilage procedure compared with those patients without a prior cartilage procedure (P > .05). Patients undergoing anteromedialization tended toward better outcomes than those without realignment. Forty-four percent of patients needed a subsequent procedure. There were 4 clinical failures (7.7%), which were defined as progression to arthroplasty or conversion to osteochondral allograft transplantation. Conclusion: Autologous chondrocyte implantation is a viable treatment option for chondral defects of the patellofemoral joint. Combined autologous chondrocyte implantation with anteromedialization improves outcomes more than autologous chondrocyte implantation alone. Patients with failed prior cartilage procedures can also expect sustained and clinically meaningful improvement.