Transcondylar reinsertion of femoral avulsions of the anterior cruciate ligament: evaluation of the position in 20 cases using three-dimensional computed tomographic reconstruction.

The position of transcondylar small-caliber drill tunnels after reinsertion of femoral avulsions of the anterior cruciate ligament (ACL) including avulsions with bone or cartilage fragments, which escape objective verification by conventional roentogenography, was determined in 20 patients by an examination procedure using computed tomography. Coronary tomograms were used for three-dimensional reconstruction of the distal end of the femur and assessment of the position of the perforation sites in the area of the medial aspect of the lateral condyle as well as the distance between them in patients in whom two Kirschner wires had been used (16 patients). A correct position had been achieved only in 4 of the 16 cases with double reinsertion and in one of four cases in which a single Kirschner wire had been used. With exception of one only partially correct placement, localization was found ventrally from the transition line with a predominantly caudally directed component. Assuming a mean thickness of the anterior cruciate ligament of 5 mm, the distance of the drill tunnels in five cases met the anatomic requirements, was too small in six cases, too large in three cases, and could not be evaluated adequately in two cases. The results of the present study illustrate vividly the problems of the surgical technique of Palmer.