Clinical experience with single-incision ACL reconstruction has shown graft-tunnel mismatch to be a potential problem. When mismatch occurs, the graft is too long for the tunnels created and protrudes from the tibial tunnel after fixation in the femoral tunnel.

Multiple techniques to resolve this issue have been described, with most of them involving alternative methods of fixation. In 1999, a clinical report of graft rotation as a method of eliminating graft-tunnel mismatch was published. In that report, the authors described a technique whereby external rotation of the graft results in an effective shortening of the ligament portion of the graft, eliminating the excess length. Although a few studies have evaluated the biomechanical properties of the normal ACL and have established the bone-patellar tendon-bone autograft as an effective graft option no study has quantified the amount of shortening or determined the effect of extreme rotation on initial graft strength. To our knowledge, the effect of graft rotation has only been evaluated at 90° and 180° of rotation.

The objectives of this study were to determine the initial ultimate load to failure in tension of central-third porcine bone-patellar tendon-bone composite grafts in various degrees of rotation and to quantify the associated graft shortening. The hypothesis of this study was that graft rotation would result in decreased load to failure.

Full Article:  Effects of Graft Rotation on Initial Biomechanical Failure Characteristics of Bone-Patellar Tendon-Bone Constructs