The anterior cruciate ligament (ACL) plays an important role in the control of knee stability by not only controlling anterior tibial translation but also varus movement and axial rotation. Rupture of the ACL can therefore significantly alter knee joint stability and result in the application of abnormal load bearing patterns on the articular surfaces. Indeed, there have been numerous studies which have observed abnormal knee movement patterns in patients following
ACL rupture. It has further been suggested, by both human and animal data, that such abnormal knee movements associated with ACL rupture could be a cause of cartilage degeneration and the eventual development of knee joint osteoarthritis. ACL reconstruction is a commonly performed procedure to restore knee joint stability and function but its effectiveness in preventing osteoarthritis is controversial. Several studies have demonstrated relatively high incidences of osteoarthritis after ACL reconstruction. This may in part be explained by the finding that the movement of the ACL reconstructed knee remains abnormal when compared to the contralateral side or to healthy control knees during a variety of static and dynamic activities. One factor which may contribute to the altered movement patterns after ACL reconstruction is that most contemporary ACL reconstruction surgeries have primarily focused on restoring anterior’posterior translation whereas the native ACL not only controls anterior’posterior translation but also internal’external rotation.
Activities that have a repetitive, cyclic nature have been suggested to be relevant to study in populations at risk for the development of knee osteoarthritis. Overground walking is one such activity. A number of studies have reported on the knee joint kinematics during walking following ACL reconstruction. However, the majority of these have focused on movements in the sagittal plane. Although the secondary planes of knee joint movement are thought to be clinically relevant in terms of the development of osteoarthritis, there is limited data regarding movements in these planes following ACL reconstruction surgery.
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