ABSTRACT
The knee is an inherently unstable joint, relying on the strong capsule, intra- and extra-articular ligaments, and muscles around the joint and cartilaginous structures for stability. Most ligament injuries occur while the knee is flexed as stabilizing structures are relaxed, permitting rotation. Injuries of the knee ligaments are common, particularly in sporting pursuits but also in road accidents, where they may be associated with fractures or dislocations. Quadriceps rehabilitation and conscious knee control can minimize sagittal instability but the risk of future pivot instability, commonly leading to chondral or meniscal instability, remains. A backslab or hinged brace is worn until control of active knee extension is regained; this is removed every day to permit active knee-flexion exercises. The knee should be examined for signs of neurovascular injury: traction injury of the peroneal or tibial nerves is not uncommon. Rare complications include progressive valgus deformity after bony healing and possible tibial overgrowth resulting in leg lengthening.
