Knee dislocation

Symptoms include knee pain. The joint may also have lost its normal shape and contour. A joint effusion may, or may not, be present. Complications Complications may include injury to the artery behind the knee (popliteal artery) in about 20% of cases or compartment syndrome. Damage to the common peroneal nerve or tibial nerve may also occur. Nerve problems, if they occur, often persist to a variable degree. ==Cause==

About half are the result of major trauma, the other half as a result of minor trauma. Minor trauma may include tripping while walking or while playing sports. ==Diagnosis==

As the injury may have self-reduced before arrival at hospital, the diagnosis may not be readily apparent. Anterior dislocations, followed by posterior, are the most common. They may also be classified on the basis of which ligaments are injured. ==Treatment==

Initial management is often based on Advanced Trauma Life Support. If the joint remains dislocated reduction and splinting is indicated. Reduction can often be done with simple traction after the person has received procedural sedation. If the joint cannot be reduced in the emergency department, then emergency surgery is recommended. In those with signs of arterial injury, immediate surgery is generally carried out. If the joint does not stay reduced external fixation may be needed. If the nerves and artery are intact the ligaments may be repaired after a few days. Multiple surgeries may be required. In just over 10% of cases an amputation of part of the leg is required. ==Epidemiology==

Knee dislocations are rare: they represent about 1 in 5,000 orthopedic injuries, and about 1 knee dislocation occurs annually per 100,000 people. Males are more often affected than females, and young adults the most often. == References ==