Autologous chondrocyte implantation for the treatment of large full-thickness cartilage lesions of the knee.

OBJECTIVE To investigate the benefit, reliability, and complication rate of autologous chondrocyte implantation (ACI) in patients with large full-thickness cartilage defects of the knee. METHODS Between March 1997 and December 2001, 71 consecutive patients (24 women, 47 men) were treated with ACI at the Freiburg University Hospital, Germany, and were included in this study. Average age was 35 years (13-61). Lesions were mainly situated on the medial femoral condyle (n=46); mean defects size was 6.61 cm2 (2-17.5), outerbridge grade III-IV. Number of previous surgical procedures was 2.13 (0-8). For outcome measurement, International Cartilage Repair Society (ICRS) knee examination form, Lysholm score, Cincinnati knee score, and the modified Cincinnati-knee-score were used. Correlation between treatment results, and previous surgical procedures was examined. Statistical analysis was performed using the 2-tailed paired and unpaired Wilcoxon-rang-sum-test (alpha=0.05). RESULTS Mean follow-up 36 months (24-65). Modified Cincinnati score overall rating demonstrated highly significant improvements from 3.24 to 6.44 points (patients) and from 3.35 to 6.87 (physicians). Mean Cincinnati score improved from 27-72 points, ICRS score improved from grade D to grade C, and average Lysholm score from 33 points to 69 points. All but 11 patients returned to casual sports, 25 patients went in for regular sports 1-3 times a week or more. Complication rate was 11%. CONCLUSION Autologous chondrocyte implantation provides an appropriate method for the treatment of full-thickness cartilage lesions of the knee and gives good clinical short-term results.