Computed tomography evaluation of the femoral and tibial attachments of the posterior cruciate ligament in vitro

Abstract
Purpose The optimal technique for reconstruction of the posterior cruciate ligament (PCL) is controversial. Regardless of surgical technique and graft choice, anatomic graft placement is essential for successful outcome. The purpose of this study is to evaluate the size and location of the insertions of the PCL using a computed tomography (CT) protocol. Methods The insertions in ten knees were marked in vitro with plastic markers. The CT examination was performed with the knee in extension. On the femur, the position of the center of the insertion site was evaluated relative to Blumensaat’s line and the anterior articular surface. On the tibia, the location of the center of the insertion site was described relative to the borders of the tibial plateau and the retrospinal surface. Results The surface area of the femoral insertion measured 232 mm−2 and was centered 8.9 mm from the roof of the intercondylar notch and 18.7 mm from the anterior articular cartilage surface. The surface area of the tibial insertion was 155 mm2 and was centered 9.1 mm from the posterior border of the tibia on the retrospinal surface, 1.6 mm inferior to the plane of the tibial articular surface. This point was on average 49% of the way across the plateau relative to the medial edge of the plateau and 87% of the way across the plateau relative to the anterior edge. Conclusions Computed tomography can provide detailed localization of the PCL attachment sites on the femur and tibia. Radiation exposure and cost may preclude routine use.