Potential healing benefit of an osteoperiosteal bone plug from the proximal tibia on a mosaicplasty donor-site defect in the knee. An experimental study in the goat.

INTRODUCTION: Autologous osteochondral transplantation is a popular treatment for articular cartilage lesions in the knee joint. The donor defect is commonly left empty and remains a matter of concern. MATERIALS AND METHODS: In 20 knees of 10 goats, we created a standardised donor defect in the knee. In the control group the defects were left empty, whereas in two other groups a bone plug from the proximal tibia was press-fitted into the defect with or without a covering periosteal layer. RESULTS: Histological evaluation after 8 and 16 weeks showed that relatively rapid osteoclastic resorption of the bone plug occurred. Defects were mainly filled with fibrous tissue, and collapse of the adjacent bone and cartilage was visible, especially when the defects were left empty. Occasionally, some consolidation of the graft to the host bone could be detected, and in some samples periosteal chondrogenesis was present. CONCLUSION: Our findings suggest that transplantation of a tibial bone plug with covering periosteum to the donor defect in a cartilage transplantation procedure does not have any additional value in an attempt to minimise the damage at the donor site. The observed resorption of the bone plug and the collapse of the adjacent joint margin remain a matter of concern with this technique