If you’re a sports fan like me, you have seen the number of knee dislocations rise over the last couple of years in all sports. Knee dislocations often occur from direct impact from an opposing object to the knee. In sports such as football, contact with the knee from opposing objects or player, is very common. These injuries often result in multiple ligament tears, which are serious enough, but dislocations may also compromise vascular structures which can lead to an acute compartment syndrome, permanent neurovascular deficits, or even an amputation of the patient’s leg. Recently, a patient presented to Vail Summit Orthopedics having suffered a knee dislocation from a noncontact injury while wakeboarding. As a consequence of seeing this patient in our clinic, as well as the notoriety generated in the media about a player suffering a recent dislocation in the NFL, I have received many questions regarding knee dislocations. Although this injury is relatively rare, recognition of the injury, stabilization, and immediate care are very important for the patient to potentially avoid lifelong disability.
They are 5 main types of knee dislocations which include anterior dislocations, posterior dislocations, medial dislocations, lateral dislocations, and rotary dislocations. The direction of dislocation references the position of the tibia (lower leg bone) in relationship to the femur (upper leg bone). Anterior knee dislocations often occur with hyperextension of the knee at high impact. Posterior dislocations often occur with a high velocity impact to the anterior aspect of the proximal tibia. The medial, lateral, and rotary dislocations occur with varus, valgus, and rotatory forces to the knee. More than half of knee dislocations occur as anterior or posterior dislocations. Anterior and posterior dislocations also have a high incidence of injury to the popliteal artery. Vascular injuries require immediate recognition and emergent treatment in order to avoid a potentially limb threatening injury.
The most recent knee dislocation in the NFL is an example of an anterior dislocation with injury to the popliteal artery. Chicago Bears tight end, Zach Miller, while jumping to make a touchdown catch , landed on an extended leg, the force of which caused him to hyperextend his knee past 30°, dislocating his knee anteriorly. This injury resulted in multiple ligament tears, as well as, severing the popliteal artery. Miller was transferred immediately to the hospital for vascular surgery repair of his popliteal artery to prevent an amputation of his left leg. Fortunately, the surgery was a success, and he will not lose his leg, but he will also require multi-ligamentous reconstructions. In contrast, the patient we saw in the clinic recently suffered no such vascular injury but experienced a rotary dislocation of his knee. However, both patients will require reconstructions of their anterior cruciate ligament, medial cruciate ligament, posterior cruciate ligament, and posterior lateral corner ligaments.
Both patients’ journey to a full recovery is just beginning. My experience as an Athletic Trainer in the NFL suggests that a full return to the high level of performance required in the NFL will be quite difficult for Mr. Miller. Having said that, most patients can resume an active life after this injury and surgery. I believe that both of these patients are fortunate due to the fact that they had the correct immediate care for knee dislocations.
Living in the mountains, most patients we see are very active and severe musculoskeletal injuries are frequent. These Injuries require recognition of the injury and the appropriate care. It is this immediate treatment that may ultimately lead to a successful outcome rather than life long disability from delayed diagnosis and subsequent care. The monitoring of research and a best practices approach to treatment of sports injuries is something that Dr. Cunningham and the team at Vail Summit Orthopedics is proud to provide.
Richard Williams, OTC, ATC to Dr. Richard Cunningham, MD.