Comparison of fixation methods of double-bundle double-tibial tunnel ACL reconstruction and double-bundle single-tunnel technique.

An experimental study was conducted in order to evaluate biomechanical methods of single-bundle reconstruction in ACL and compare it with a new double-bundle double-tibial tunnel technique. Twenty-four porcine cadaver knees, divided into 4 groups of 6 knees each and 48 proper extensors of the fourth toe tendons, were used for the fixation techniques. In groups A and B, a double-bundle technique with a single femoral and tibial tunnel was used, fixed to a femoral and tibial post with screws and with buttons, respectively. In groups C and D, a double-bundle technique (technique Delta) with two separate tibial tunnels was used, fixed to a femoral and tibial post with screws and with buttons, respectively. A material testing system (Instron) was used for anteriorly translating the tibia until failure. The femoral and tibial post as a fixation method is superior to the conventional buttons technique. The more anatomical double-bundle reconstruction technique provided significantly higher structural properties and smaller loss of fixation compared with the single-bundle reconstruction technique. The comparison of the two techniques gave superior results to the femoral and tibial screws over the buttons. The double-bundle technique attempts to restore the anterior stability of the knee joint.