ANALYSIS OF A SEMITENDINOSUS AUTOGRAFT IN A RABBIT MODEL

The purpose of this study was to evaluate the histologic and biomechan ical changes that occur between 12 and 52 weeks in an intraarticular, semitendinosus autograft placed through tibial and femoral drill holes in a rabbit model. The results of this study show that, in this rabbi t model, the soft tissue graft maintained its biologic fixation in the osseous tunnel when stressed to failure at 1 year. The bony fixation occurred by the formation of an indirect tendon insertion, and this fo rmation was complete by 26 weeks. At 52 weeks, large differences persi sted in the strength and stiffness of the graft compared with the norm al semitendinosus tendon and anterior cruciate ligament. Based on the results of this study, we support a cautious approach in returning pat ients to early full activity, including sports, after anterior cruciat e ligament reconstruction with a semitendinosus autograft.