In Vivo Three-Dimensional Imaging Analysis of Femoral and Tibial Tunnel Locations in Single and Double Bundle Anterior Cruciate Ligament Reconstructions

BACKGROUND Anatomic footprint restoration of anterior cruciate ligament (ACL) is recommended during reconstruction surgery. The purpose of this study was to compare and analyze the femoral and tibial tunnel positions of transtibial single bundle (SB) and transportal double bundle (DB) ACL reconstruction using three-dimensional computed tomography (3D-CT). METHODS In this study, 26 patients who underwent transtibial SB ACL reconstruction and 27 patients with transportal DB ACL reconstruction using hamstring autograft. 3D-CTs were taken within 1 week after the operation. The obtained digital images were then imported into the commercial package Geomagic Studio v10.0. The femoral tunnel positions were evaluated using the quadrant method. The mean, standard deviation, standard error, minimum, maximum, and 95% confidence interval values were determined for each measurement. RESULTS The femoral tunnel for the SB technique was located 35.07% ± 5.33% in depth and 16.62% ± 4.99% in height. The anteromedial (AM) and posterolateral (PL) tunnel of DB technique was located 30.48% ± 5.02% in depth, 17.12% ± 5.84% in height and 34.76% ± 5.87% in depth, 45.55% ± 6.88% in height, respectively. The tibial tunnel with the SB technique was located 45.43% ± 4.81% from the anterior margin and 47.62% ± 2.51% from the medial tibial articular margin. The AM and PL tunnel of the DB technique was located 33.76% ± 7.83% from the anterior margin, 45.56% ± 2.71% from the medial tibial articular margin and 53.19% ± 3.74% from the anterior margin, 46.00% ± 2.48% from the medial tibial articular margin, respectively. The tibial tunnel position with the transtibial SB technique was located between the AM and PL tunnel positions formed with the transportal DB technique. CONCLUSIONS Using the 3D-CT measuring method, the location of the tibia tunnel was between the AM and PL footprints, but the center of the femoral tunnel was at more shallow position from the AM bundle footprint when ACL reconstruction was performed by the transtibial SB technique.