Traumatic Dislocation of the Knee
Traumatic dislocation of the knee was once defined as the complete loss of the tibiofemoral articulation. More recently, this definition has been expanded to include bicruciate injuries of the knee and any knee injury that includes 3 or more major ligaments. The incidence of these injuries is rising due to several factors, including the expanded definition, an improved awareness of multiligament knee injuries, and the increase in the number of people participating in high speed, risk-taking sports. However, it is still estimated that the average orthopedic surgeon will only treat three or four of these injuries during their entire career.
Management of the dislocated knee begins with a careful physical and radiological examination. Associated injuries such as fractures and arterial lesions are common and need to be excluded. Currently, there is controversy in the orthopedic literature regarding whether or not an arteriogram is a necessary part of this evaluation. There is consensus, however, that the early management of the multi-ligament knee injury includes prompt reduction and immobilization of the knee joint with frequent reassessment to ensure maintenance of reduction and adequate limb perfusion. Surgery in the acute setting is generally limited to those injuries that cannot be kept in a reduced position or when a fracture or arterial injury is present.
Definitive treatment of the dislocated knee has evolved over the last 30 years as knowledge of these injuries has increased and less-invasive operative techniques have been refined. Currently, nonoperative treatment is generally limited to older or inactive patients or those with other serious injuries such as traumatic brain injury. Surgical repair or reconstruction of all major ligaments injured is the mainstay of treatment for most patient. Magnetic resonance imaging (MRI) is a valuable tool for assessing the extent of injury and for planning the reconstructive procedure. Surgery may be performed within two weeks of the knee injury or delayed several weeks until motion in the joint is restored, depending on which knee structures are injured.
Rehabilitation after the treatment of the multi-ligament knee injury is a lengthy process regardless of whether or not surgery is performed. The specific protocol depends on several factors, such as the presence or absence of associated injuries, the number and type of ligaments disrupted and the integrity of the repair or reconstruction. However, prevention of scar tissue and knee stiffness with range of motion exercises is an important part of any therapy program. Due to the severe nature of the initial knee injury, it may take up to one year to regain full motion of the knee and to resume athletic participation. The outcome after surgical treatment is good or excellent in most patients; however, limitations in activity are not uncommon.