Reduction of femoral interference screw divergence during endoscopic anterior cruciate ligament reconstruction

One of the complications of endoscopic anterior cruciate ligament (ACL) reconstruction is femoral interference screw divergence, usually occurring when the femoral screw insertion is different than the portal used for reaming the femoral tunnel. A new technique using a StraightShot graft passer (DePuy Orthopaedic Technology, Tracy, CA) allows the safe passage of a 7 mm M. Kurosaka Advantage cannulated femoral interference screw (DePuy) through the tibial tunnel with the patella tendon graft fully in position. This study compares femoral interference screw divergence in bone-patellar tendon-bone ACL reconstruction using two different screw insertion portals: the accessory anteromedial patella portal and the tibial tunnel portal (StraightShot technique). A radiographic analysis of 81 consecutive endoscopic ACL reconstructions was performed. The total divergence of each femoral screw was measured on both anteroposterior and lateral radiographs and then combined. Group I had the 7-mm femoral screw inserted through the accessory anteromedial patella portal; group II had the femoral screw inserted directly through the tibial tunnel. Group I showed more than 10 degrees of divergence in 50% of the cases, compared with only 4% percent in group II. The average divergence dropped from 11.3 degrees in group I to 1.2 degrees in group II. Femoral interference screw divergence can be virtually eliminated by inserting the femoral screw directly through the tibial tunnel using the StraightShot technique.