Comparison of Single- versus Double-Tunnel Tendon-to-Bone Healing in an Ovine Model: A Biomechanical and Histological Analysis

BackgroundThe double-bundle technique has recently gained much interest in ligament reconstruction. In addition to potential kinematic advantages, perhaps double tunnels have the potential for faster and more secure tendon-to-bone healing.HypothesisPlacement of tendons in 2 osseous tunnels, as opposed to 1, will enhance tendon fixation as determined biomechanically and histologically.Study DesignControlled laboratory study.MethodsFourteen sheep were used, and an extra-articular tendon graft reconstruction was performed on both knees of each sheep. In 1 randomly selected knee, the long digital extensor tendon was released from the femur and placed into a single tunnel in the proximal tibia. In the contralateral knee, the tendon was split and placed into 2 tibial tunnels. Ten sheep were analyzed by mechanical testing, and the remaining 4 were subjected to histologic evaluation at 6 weeks after surgery. Paired t tests were used for statistical analysis.ResultsMechanical testing demonstrated that the peak loa...