Graft fixation strength with arthroscopic anterior cruciate ligament reconstruction. Two-incision rear entry technique compared with one-incision technique.

Abstract

To compare the fixation strengths of two arthroscopic anterior cruciate ligament reconstruction techniques, we harvested 10-mm bone-patellar tendon-bone grafts with 25-mm bone plugs from 12 fresh-frozen cadaveric knees. One knee of each pair was fixed using Acufex instruments and the two-incision technique; one knee was fixed using Arthrotek instruments and the one-incision technique. We used cannulated 9 x 25 mm Kurosaka screws for femoral and tibial tunnel fixation. All knees were mounted on the Instron Test System and were stressed to failure by recreating a pivot shift maneuver. The one-incision technique graft fixation was significantly stronger (mean failure, 695 N) than that with the two-incision technique (mean failure, 593 N). In all one-incision technique knees, either the patellar tendon graft avulsed off a bone plug or the plug broke. In five of six two-incision technique knees, the tibia bone plug pulled out around the interference screw. Patellar tendon graft length ranges from 90 to 105 mm, and the average two-incision technique tunnel length is 120 mm. The interference screw compressed the femoral bone plug into conical bone but compressed the tibial bone plug into cancellous bone in the two-incision technique, while in the one-incision technique the bone plug was compressed into cortical bone on both sides.