Collapsing the tibial bone tunnel in hamstring autograft reconstruction of the anterior cruciate ligament.

Abstract

The use of double staples is an accepted method for fixation of hamstring anterior cruciate ligament (ACL) grafts at the distal tibial site. In the last year, we have modified the 2-staple technique that we have been using for distal tibial fixation of our double loop hamstring ACL autografts. Previously, we had impacted the graft with 2 toothed staples onto the cortex distal to the opening of the tibial tunnel. The modification we report here involves driving the proximal staple into the tibial tunnel roof, thus collapsing the tunnel onto the tendon during fixation. The distal staple is introduced in the usual manner. Clinical follow-up including subjective and objective KT-1000 arthrometry has indicated no difference in the early results compared with the former staple technique. Radiologic follow-up showed tunnel obliteration and filling in the area of the proximal staple, suggesting early graft incorporation in callus. While early results are encouraging, long-term follow-up and pullout studies will be reported. It would appear that collapsing the bony tunnel by the proximal staple may be a simple method of providing fracture callus to increase the stiffness of the tibial graft fixation, with no major or minor complications. Animal experiments are being carried out to objectively define the mechanical advantage of the graft incorporation by callus.