Neochondrogenesis in repair of full-thickness articular cartilage defects using free autogenous periosteal grafts in the rabbit. A follow-up in six months

Objective: To analyse the repair of lesions of articular cartilage with per iosteum-free implants and follow-up at 6 months. Design: Thirty-six New Zealand rabbits, 4-6 weeks old, were used. Full-thic kness articular cartilage defects in the medial femoral condyle were create d. Spontaneous evolution occurred in 18 animals; the other 18 animals were treated with a free autogenous periosteal tibial implant fixed with Tissuco l(R). Animals were killed in groups of six at 8, 12 and 24 weeks. Macroscop ic, histologic and histochemical results were evaluated and analysed statis tically using the Mann-Whitney U-test. Results: The spontaneous evolution of the lesion did not lead to complete r epair in any case, The periosteum-free implant provided complete repair of the lesion and statistically significant restoration of the articular surfa ce. Conclusions: In the rabbit, this study confirms the incomplete spontaneous repair of articular cartilage and the chondrogenic potential of tibial peri osteum-free implants, with long-term maintenance of the macroscopic, histol ogic and histochemical characteristics of neo-cartilage. This raises the po ssibility of its use as an alternative method in the repair of circumscribe d osteochondral lesions in young patients. (C) 2000 OsteoArthritis Research Society International.