Arbitrary starting point of separation affects morphology of the 2 bundles of anterior cruciate ligament at insertion sites.

摘要

PURPOSE: To explore whether changes in the starting point of separation affect the morphology of the 2 bundles of the anterior cruciate ligament (ACL) at insertion. METHODS: Ten cadaveric knees were used to separate the ACL fibers into 2 bundles from 3 different starting points that were located at the proximal one fifth, two fifths, and three fifths of the inter-bundle mark line. The dividing lines between the 2 bundles at insertion and the area of the anteromedial (AM) bundle resulting from these different separations were compared, with data collected in groups I, II, and III, respectively. RESULTS: The angle of the dividing line and the long axis of the femoral footprint was 67.24 degrees +/- 11.94 degrees, 91.01 degrees +/- 11.16 degrees, and 116.03 degrees +/- 9.01 degrees in groups I, II, and III, respectively, and the percentage of the AM bundle area in the whole femoral footprint was 38.64% +/- 5.55%, 52.22% +/- 6.76%, and 65.09% +/- 4.53%, respectively. At the tibial insertion sites, the angle between the dividing line and the sagittal plane was 110.17 degrees +/- 13.26 degrees, 127.72 degrees +/- 8.94 degrees, and 149.28 degrees +/- 18.80 degrees in groups I, II, and III, respectively, and the percentage of the AM bundle area in the whole footprint was 25.72% +/- 3.82%, 40.41% +/- 3.73%, and 60.56% +/- 6.59%, respectively. There were statistical differences between the angle and the area data of each of the 2 groups at either the tibial or femoral insertion site. CONCLUSIONS: In an anatomic study of the ACL, changes in the point from which separation started resulted in noticeably different bundle morphology at the insertion. CLINICAL RELEVANCE: Proper separation will lead to a more accurate bundle description and, thus, a more accurate location of the tunnels in ACL reconstruction.