Autologous chondrocyte implantation in the knee using fibrin

Autologous chondrocyte implantation (ACI) is widely used to treat symptomatic articular cartilage injury of the knee. Fibrin ACI is a new tissue-engineering technique for the treatment of full-thickness articular cartilage defects, in which autologous chondrocytes are inserted into a three-dimensional scaffold provided by fibrin gel. The objective of this study is to document and compare mean changes in overall clinical scores at both baseline and follow-up. Fibrin ACI was used to treat deep cartilage defects of the femoral condyle in 30 patients. There were 24 men and 6 women with a median age of 35 years (range 15–55) and with a mean defect size of 5.8 cm² (range 2.3–12). Clinical and functional knee evaluations were performed using different scoring systems, MRI was performed 24 months postoperatively, and arthroscopy was performed 12 months postoperatively. All patients achieved clinical and functional status improvements following surgery (P < 0.01). The mean scores of the Henderson classification (MRI evaluation) significantly improved from 14.4 to 7 (P = 0.001), and no graft-associated complications were noted. Arthroscopic assessments performed 12 months postoperatively produced nearly normal (grade II) International Cartilage Repair Society scores in 8 of the 10 study patients. Fibrin ACI offers the advantages of technical simplicity, minimal invasiveness, a short surgery time, and easier access to difficult sites than classical ACI. Based on the findings of this clinical pilot study, we conclude that fibrin ACI offers a reliable means of treating articular cartilage defects of the knee.