Single-bundle anterior cruciate ligament reconstruction: A biomechanical cadaveric study of a rectangular quadriceps and bone-patellar tendon-bone graft configuration versus a round hamstring graft

Abstract

Purpose The purposes of this study were to investigate anterior tibial translation under loading conditions after single-bundle (SB) anterior cruciate ligament (ACL) reconstruction using a rectangular tunnel placement strategy with quadriceps and bone-patellar tendon-bone (BPTB) graft and to compare these data with a SB hamstring reconstruction with a round tunnel design. Methods In 9 human cadaveric knees, the knee kinematics were examined with robotic/universal force-moment sensor testing. Within the same specimen, the knee kinematics under simulated pivot-shift and KT-1000 arthrometer (MEDmetric, San Diego, CA) testing were determined at 0, 15, 30, 60, and 90 of flexion under different conditions: intact knee, ACL-deficient knee, and SB ACL-reconstructed knee. For the SB ACL-reconstructed knee, 3 different SB reconstruction techniques were used: a rectangular tunnel strategy (9 × 5 mm) with quadriceps graft, a rectangular tunnel strategy with BPTB graft, and a round tunnel strategy (7 mm) with hamstring graft. Results In a simulated Lachman test, a statistically significant difference was found at 0 and 15 of knee flexion between the rectangular reconstruction with quadriceps graft (5.1 ± 1.2 mm and 8.3 ± 2 mm, respectively) or BPTB graft (5.3 ± 1.5 mm and 8 ± 1.9 mm, respectively) and the reconstruction using hamstring graft (7.2 ± 1.4 mm and 12 ± 1.8 mm, respectively) (P =.032 and P =.033, respectively, at 0; P =.023 and P =.02, respectively, at 15). On the simulated pivot-shift test at 0 and 15, rectangular ACL reconstruction with quadriceps graft (3.9 ± 2.1 mm and 6.5 ± 1.7 mm, respectively) or BPTB graft (4.2 ± 1.8 mm and 6.7 ± 1.7 mm, respectively) showed a significantly lower anterior tibial translation when compared with round tunnel reconstruction (5.5 ± 2.1 mm and 7.9 ± 1.9 mm, respectively) (P =.03 and P =.041, respectively, at 0; P =.042 and P =.046, respectively, at 15). Conclusions Under simulated Lachman testing and pivot-shift testing, a reconstruction technique using a rectangular tunnel results in significantly lower anterior tibial translation at 0 and 15 of flexion in comparison to knees reconstructed with a hamstring SB graft using a round tunnel strategy. Clinical Relevance ACL reconstruction with a rectangular tunnel and BPTB and quadriceps tendon might result in better anterior knee stability at low flexion angles than ACL reconstruction with hamstring SB graft and a round tunnel in the clinical setting. © 2013 by the Arthroscopy Association of North America.