Abstract
Secondary knee osteoarthritis in young patients frequently occurs after subtotal meniscectomy. Partial meniscus reconstruction （PMR） surgery is performed if no other treatment option for such patients is available and only when the posterior meniscal section remains intact after trauma. PMR surgery was performed using autologous tendons by creating bone tunnels at different positions of the tibia in an osteoarthritic rabbit model. The effects on femoral condyle cartilage and osteophyte formation degeneration were then histologically examined. The medial meniscus of 15 rabbits was partially resected and reconstructed with an autograft of the extensor digitorum longus tendon. Posterior bone tunnels were created on the tibial articular surface for graft tendon fixation （articular surface group） in the rabbits’ right knees. Posterior bone tunnels were created at the medial tibial angle （extra-articular group） in the same rabbits’ left knees. Every 2, 4, 8, 12, and 18 weeks after surgery, three rabbits were sacrificed. Granular area injury in the femoral condyle cartilage and osteophyte formation were histologically evaluated as per Kamekura’s grading system. The results showed no significant difference in the femoral condyle cartilage injury and osteophyte formation between groups, except for low-grade osteophyte formation at four weeks after surgery for the extra-articular group （p＜0.05）. These results suggest that the advantage of creating posterior bone tunnels at the medial tibial angle is ameliorating tibial articular cartilage injury and tendon autograft, as we reported in a previous paper, rather than ameliorating femoral condyle cartilage injury and osteophyte formation, which were tested in the current study. At present, we recommend an extra-articular surface rather than an articular surface as the site for creating bone tunnels for fixing the tendon graft for better knee osteoarthritis prognosis. Further studies are warranted to establish the clinical implication of the current animal experiments.
