Measurement of the End-to-End Distances Between the Femoral and Tibial Insertion Sites of the Anterior Cruciate Ligament During Knee Flexion and With Rotational Torque

• Published in: Arthroscopy Vol. 28; no. 10; pp. 1524 - 1532
• Main Authors: Wang, Joon Ho, M.D., Ph.D, Kato, Yuki, M.D., Ph.D, Ingham, Sheila J.M., M.D., M.S, Maeyama, Akira, M.D., Ph.D, Linde-Rosen, Monica, B.S., R.N, Smolinski, Patrick, Ph.D, Fu, Freddie H., M.D., D.Sc., D.Ps.(Hon.)
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.10.2012; Elsevier
• Subjects: Aged; Anterior Cruciate Ligament - anatomy & histology; Anterior Cruciate Ligament - physiopathology; Anterior Cruciate Ligament - surgery; Arthroscopy; Biological and medical sciences; Biomechanical Phenomena; Body Weights and Measures; Cadaver; Endoscopy; Female; Femur - surgery; Humans; Investigative techniques, diagnostic techniques (general aspects); Knee Joint - physiopathology; Knee Joint - surgery; Male; Medical sciences; Middle Aged; Orthopedic surgery; Orthopedics; Range of Motion, Articular; Robotics; Rotation; Stress, Mechanical; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Tibia - surgery; Torque; Knee; Femur; Arthroscopy; Orthopedic surgery; Treatment; Tibia; Insertion; Endoscopy; Anterior cruciate ligament
• ISSN: 0749-8063; 1526-3231
• DOI: 10.1016/j.arthro.2012.03.004

Purpose The aim of this study was to determine the end-to-end distance changes in anterior cruciate ligament (ACL) fibers during flexion/extension and internal/external rotation of the knee. Methods The positional relation between the femur and tibia of 10 knees was digitized on a robotic system during flexion/extension and with an internal/external rotational torque (5 Nm). The ACL insertion site data, acquired by 3-dimensional scanning, were superimposed on the positional data. The end-to-end distances of 5 representative points on the femoral and tibial insertion sites of the ACL were calculated. Results The end-to-end distances of all representative points except the most anterior points were longest at full extension and shortest at 90°. The distances of the anteromedial (AM) and posterolateral (PL) bundles were 37.2 ± 2.1 mm and 27.5 ± 2.8 mm, respectively, at full extension and 34.7 ± 2.4 mm and 20.7 ± 2.3 mm, respectively, at 90°. Only 4 knees had an isometric point, which was 1 of the 3 anterior points. Under an internal torque, both bundles became longer with statistical meaning at all flexion angles ( P = .005). The end-to-end distances of all points became longest with internal torque at full extension and shortest with an external torque at 90°. Conclusions Only 4 of 10 specimens had an isometric point at a variable anterior point. The end-to-end distances of the AM and PL bundles were longer in extension and shorter in flexion. Clinical Relevance The nonisometric tendency of the ACL and the end-to-end distance change during knee flexion/extension and internal/external rotation should be considered during ACL reconstruction to avoid overconstraint of the graft.