Knee dislocations are acute injuries, and do not occur frequently. If misdiagnosed, major complications can result. Knee dislocation occurs as a result of a traumatic fall, high-speed injury, or a sports related collision. Once the knee becomes dislocated, it will visibly look deformed, and will result in severe pain. Reduction may occur spontaneously; otherwise, relocating the knee back to its original position is crucial, and sometimes requires anesthesia. Due to the complexity of the injury, knee dislocation is difficult to manage. Nerve or blood vessel damage, fracture, or compartment syndrome are common injuries associated with knee dislocations, and may require multiple specialists.

Symptoms and Diagnosis

Symptoms of a dislocated knee will include intense pain, swelling, stiffness, and deformity. Initial treatment is emergent, and requires careful evaluation including special tests for nerve, or blood vessel damage. If a knee dislocation has occurred, and emergent conditions have been evaluated or ruled out, your physician will order an X-ray and MRI. Typically, multiple ligaments are injured along with the dislocation, including the ACL, PCL, LCL, or MCL. The meniscus and cartilage may also be injured.


A dislocated knee usually results in surgery because of multi-ligament damage. In a small percentage of cases, a vascular surgeon may also be needed to assist if blood vessel damage has occurred. Once emergent conditions are ruled out, and the patient is stable, your physician will perform the cruciate ligament (ACL and/or PCL) surgery via an arthroscopic method, and because the collateral ligaments are on the outside of the knee, he may need to perform open surgery to reconstruct the collateral ligaments. During surgery, he will reconstruct the ligaments using allografts, in addition to utilizing strong sutures and additional hardware (buttons or screws) to secure nearby structures. Typically, the surgery is performed a minimum of 3 weeks after injury.


Because of the nature and severity of knee dislocation, rehabilitation may be prolonged; however, physical therapy will also be a progressive process. Therapy will include slow initiation of range of motion, strengthening, and return to activities. Full recovery and return to a high activity level may take 9-12 months.