Third-generation autologous chondrocyte implantation versus mosaicplasty for knee cartilage injury: 2-year randomized trial

Numerous surgical techniques have been developed to treat osteochondral defects of the knee. A study reported encouraging outcomes of third-generation autologous chondrocyte implantation achieved using the solid agarose-alginate scaffold Cartipatch®. Whether this scaffold is better than conventional techniques remains unclear. This multicenter randomized controlled trial compared 2-year functional outcomes (IKDC score) after Cartipatch® versus mosaicplasty in patients with isolated symptomatic femoral chondral defects (ICRS III and IV) measuring 2.5-7.5 cm(2) . In addition, a histological evaluation based on the O'Driscoll score was performed after 2 years. We needed 76 patients to demonstrate an at least 10-point subjective IKDC score difference with α = 5% and 90% power. During the enrolment period, we were able to include 55 patients, 30 of them were allocated at random to Cartipatch® and 25 to mosaicplasty. After 2 years, eight patients had been lost to follow-up, six in the Cartipatch® group, and two in the mosaicplasty group. The baseline characteristics of the two groups were not significantly different. The mean IKDC score and score improvement after 2 years were respectively 73.7 ± 20.1 and 31.8 ± 20.8 with Cartipatch® and 81.5 ± 16.4 and 44.4 ± 15.2 with mosaicplasty. The 12.6-point absolute difference in favor of mosaicplasty is statistically significant. Twelve adverse events were recorded in the Cartipatch® group against six in the mosaicplasty group. After 2 years, functional outcomes were significantly worse after Cartipatch® treatment compared to mosaicplasty for isolated focal osteochondral defects of the femur.