A Single Cycle Study of Screw Fixation in Anterior Cruciate Ligament Reconstruction

The natural history of Anterior Cruciate rupture is one of progressive deterioration of knee function, with the development of instability, meniscal tears and post traumatic osteoarthritis. The current surgical approach is for anatomical reconstruction using a biological tissue autograft. It is well understood that the initial stability is dependent on the strength of the fixation rather than the strength of the graft, until the graft becomes biologically incorporated in the bone tunnel. A study was carried out to better understand postoperative internal bone stresses in anterior cruciate ligament (ACL) reconstruction surgery. The mechanical aspects of an interface screw fixation were examined both experimentally and numerically, with the aim to minimize deleterious effects in ACL reconstruction. The tibial cortical/cancellous bony tunnel and the stress pattern resulting from the screw fixation in the tunnel are investigated.