Treatment outcomes of autologous chondrocyte implantation for full-thickness articular cartilage defects of the trochlea

Background: The treatment of trochlear cartilage lesions is challenging given the likely presence of other patellofemoral joint pathologies, the topography of the area, and the limited available treatment options. Only 1 other study has examined the effectiveness of autologous chondrocyte implantation for lesions of the patellofemoral joint. Hypothesis: Patients treated with autologous chondrocyte implantation for moderate to large isolated lesions located on the trochlea will report improvement in the modified overall condition scale score of the Cincinnati Knee Rating System at a minimum 2-year follow-up. Study Design: Case series; Level of evidence, 4. Methods: Using modified scales of the Cincinnati Knee Rating System, 40 Cartilage Repair Registry patients rated their overall condition and symptoms at baseline and at a mean follow-up of 59 +/- 18 months. Factors likely to affect outcomes also were analyzed. Results: At baseline, patients were between ages 16 to 48 years, had a mean total defect size of 4.5 cm(2), and reported an overall condition score of 3.1 points (poor). Many failed a prior marrow-stimulation procedure (48%). Other procedures per-formed before baseline included tibiofemoral osteotomy in 23% and lateral release or Fulkerson for patella maltracking in 13%. Forty-three percent were receiving workers' compensation at baseline. Patients reported statistically significant improvement in their mean overall condition (3.1 points preoperatively to 6.4 points postoperatively), pain (2.6 to 6.2 points), and swelling (3.9 to 6.3 points) scores. Eleven patients experienced 17 subsequent procedures, and no patients had a failed implantation. Conclusion: Autologous chondrocyte implantation appears to improve function and reduce symptoms in young to middle-aged patients with symptomatic, full-thickness articular cartilage lesions of the trochlea.