Loss of Knee Extension After Anterior Cruciate Ligament Reconstruction : Effects of Knee Position and Graft Tensioning

• Published in: Journal of bone and joint surgery. American volume 2007-07, Vol.89A (7), p.1565-1574
• Main Authors: AUSTIN, John C, PHORNPHUTKUL, Chanakarn, WOJTYS, Edward M
• Format: Article
• Language: English
• Subjects: Anterior Cruciate Ligament - physiopathology; Anterior Cruciate Ligament - surgery; Biological and medical sciences; Bone-Patellar Tendon-Bone Grafting; Cadaver; Humans; Knee Joint - physiopathology; Knee Joint - surgery; Medical sciences; Orthopedic surgery; Pilot Projects; Range of Motion, Articular; Reconstructive Surgical Procedures; Stress, Mechanical; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases
• ISSN: 0021-9355; 1535-1386
• DOI: 10.2106/00004623-200707000-00021

Loss of knee extension has been reported by many authors to be the most common complication following anterior cruciate ligament reconstruction. The objective of this in vitro study was to determine the effect, on loss of knee extension, of the knee flexion angle and the tension of the bone-patellar tendon-bone graft during graft fixation in a reconstruction of an anterior cruciate ligament. The anterior cruciate ligament was reconstructed with use of tibial and femoral bone tunnels placed in the footprint of the native anterior cruciate ligament in ten cadavers. The graft was secured with an initial tension of either 44 N (10 lb) or 89 N (20 lb) applied with the knee at 0 degrees or 30 degrees of flexion. The knee flexion angle was measured with use of digital images following graft fixation. Tensioning of the graft at 30 degrees of knee flexion was associated with loss of knee extension in this cadaver model. Graft tension did not affect knee extension under the conditions tested. The results suggest that one of the common causes of the loss of full knee extension may be diminished if the graft is secured in full knee extension when the tibial and femoral tunnels are placed in the footprint of the native anterior cruciate ligament. More importantly, even when the femoral and tibial tunnels are placed in the femoral and tibial footprints of the native anterior cruciate ligament, fixing a graft in knee flexion can result in the loss of knee extension.