93.1 Knee injuries are common today across the whole spectrum of trauma but this chapter will concentrate on knee injuries which are likely to occur to a car occupant [where there is likelihood of a whiplash injury]. A restrained car occupant is likely to suffer knee injury mainly from dashboard contact. This is usually a blow to the anterior aspect of the knee. The main area of injury will be the patella. Other fractures can occur to the lower femur or upper tibia and there maybe ligamentous injuries such as those to the anterior or posterior ligament in particular.

93.2 The knee is a complex joint anatomically. It lacks bone congruity and depends on three sets of structures for its stability. These three structures are the ligaments, the menisci and the musculo-tendinous units. An injury may damage different parts of the knee complex and to a differing degree. The whole injury complex is then subject to the management of the injury and its rehabilitation programme.

93.3 One of the problems in rehabilitation is the loss of proprioception of the joint, proprioception is the ability inherently to know where the joint is in space which includes its degree of bend and rate of change of bend. The loss of proprioception can lead to different functional results in similar injuries in similar patients. It is thus not uncommon to see people with gross disability from a cruciate injury in one patient but others with a similar injury that can play high quality sport.

93.4 The functional outcome of an injury and prognosis after a knee injury are often difficult to predict due to the complex inter-relationship of the anatomical structures. However certain patterns of injury have been recognised over the