Biomechanics of the anterior cruciate ligament and implications for surgical reconstruction

Abstract

identified as significantly influencing the biomechanical characteristics and the functional outcome of an ACL reconstructed knee joint. These factors are: (1) individual choice of autologous graft material using either patellar tendon-bone grafts or quadrupled hamstring tendon grafts, (2) anatomical bone tunnel placement within the footprints of the native ACL, (3) adequate substitute tension after cyclic graft preconditioning, and (4) graft fixation close to the joint line using biodegradable graft fixation materials that provide an initial fixation strength exceeding those loads commonly expected during rehabilitation. Under observance of these factors, the literature encourages midto long-term clinical and functional outcomes after ACL reconstruction. Key words Anterior cruciate ligament • ACL reconstruction • Biomechanics • Graft fixation • Graft tension IntroductionThe anterior cruciate ligament (ACL) is one of the most frequently injured structures of the knee joint [1]. Because of its key function as the primary restraint against anterior tibial translation, ACL disruption inevitably causes alterations in knee kinematics which are most likely to result in secondary degenerative changes and long-term functional impairment [2, 3]. As the ACL fails to heal in a manner that would restore normal knee kinematics, reconstructive techniques have been emphasised for patients who desire restoration of knee function and stability as well as return to high-level physical performance [4]. Although current concepts in knee ligament repair are reported to be clinically successful in most trials, ACL reconstruction has failed from a biomechanical point of view to both fully restore normal knee kinematics and to anatomically mimic the native ACL. Therefore, it may be postulated that surgi- Abstract Injury to the anterior cruciate ligament (ACL) is regarded as critical to the physiological kinematics of the femoral-tibial joint, its disruption eventually causing long-term functional impairment. Both the initial trauma and the pathologic motion pattern of the injured knee may result in primary degenerative lesions of the secondary stabilisers of the knee, each of which are associated with the early onset of osteoarthritis. Consequently, there is a wide consensus that young and active patients may profit from reconstructing the ACL. Several factors have been

Functional outcome of anterior cruciate ligament reconstruction with quadruple hamstring tendon graft using EndoButton and bioabsorbable interference screw: minimum 2-year follow-up

“…14 The cortical suspensory method provides excellent fixation strength, but it has been associated with bungee cord effect and a windshield wiper effect due to the far fixation point from the articular surface. 15,16 The cortico-cancellous suspension method like the cross pin fixation is said to have strong stability and stiffness due to its rigid fixation.…”

Anatomical single bundle anterior cruciate ligament reconstruction

“…The anteromedial bundle is tighter in knee flexion and the posterolateral bundle is tighter in extension [30]. Cadaveric studies have shown that the AM bundle takes most of the load during anterior tibial translation at high flexion angles whereas the PL bundle resists 30-40% of the rotatory force at low flexion angles [31].…”

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“…The ACL attaches in front of the intercondyloid eminence of the tibia, being blended with the anterior horn of the medial meniscus. [1] ACL often resists against the anterior tibial displacement. [2] ACL tear is a common knee ligament injury mainly caused by trauma during labor, accidents, and sports.…”