Autograft and Leeds-Keio Reconstructions of the Ovine Anterior Cruciate Ligament

This study compared the Leeds-Keio prosthesis with grafting of autogeneic patellar tendon for the reconstruction of the ovine anterior cruciate ligament under controlled conditions. Reconstructed knees from six sheep of each group were evaluated at 12, 26, and 52 weeks postreconstruction with respect to clinical assessment, gross pathology, mechanical properties, and histology. Although no difference in clinical assessment (anteroposterior draw, range of motion, and function) was noted between the prosthesis reconstruction and the autograft reconstruction, the prosthesis provided a higher strength initially, which remained relatively constant over the one-year study. However, prosthesis wear was observed, with up to 50% of Dacron fibers ruptured in some cases. Histologic sections indicated that in the ovine model, the Leeds-Keio prosthesis should be considered an artificial device and not a scaffold or stent that supports aligned collagenous growth. The autograft had low strength at 12 weeks, which increased over the study period. Despite acceptable clinical performance and adequate mechanical properties up to one year postimplantation, neither reconstruction approached the clinical or mechanical performance of the normal anterior cruciate ligament in the ovine model.