out of joint

Monday, May 9, 2011

Elite athletes seem to possess amazing recuperative powers, returning to play when mere mortals would be lying on a couch licking their wounds. The latest resurrected injury victim is Boston Celtic, Rajon Rondo, whose dislocated elbow was relocated in the locker room and was able to return to play in the second of a playoff game. The ability to play through pain is often expected but sometimes the concept can be taken to the extreme.

Dislocated elbows are relatively common and usually pretty easy to put back in place but there usually is an inordinate amount of pain and swelling that is associated with the olecranon, the pointed part of the elbow, being driven backwards and literally ripping the humeral condyles out of the socket. Normal recovery and return to play usually takes three to six weeks. Surgery is rarely needed and early range of motion is the key in healing to prevent a stiff joint.

While Mr. Rondo likely won’t be risking the potential for long term harm, all joints aren’t created equal. Complications of dislocations can range from inconvenience to disaster and it is important to anticipate problems before they actually happen. It is the risk of potential disaster that often drives the way dislocations are initially evaluated and treated.

For most doctors who deal with trauma, a knee dislocation is perhaps the injury with the most potential for bad to happen. Fortunately it is relatively uncommon, but when the tibia is pushed backwards behind the femur, damage can occur to the arteries that run behind the knee. In this situation, the bones don’t matter; it all has to the potential loss of blood supply to the leg and foot, and if not recognized and corrected can lead to tissue death and the need for amputation. Teaching suggests that if the knee looks dislocated, it should be relocated immediately, even before x-rays, to prevent artery damage. The real life issue is that when a knee dislocates, all the ligaments that hold it in place are torn making it very floppy, so loose that it can flop back into place. The knee may initially look normal but the risk of artery damage is still there. By the way, a knee dislocation is not the patella or kneecap dislocation scenario that has nothing to do with the knee joint itself.

Hip dislocations have their own set of problems. The hip usually dislocates posteriorly, often due to a car accident, where the bent knee hits the dashboard and drives the femoral head backwards and out of the hip socket. The arteries that supply the leg run in the front of the hip and aren’t usually damaged. Unfortunately, the femoral head or ball of the hip joint, gets its blood supply from small arteries that run within the joint itself. If the hip isn’t relocated in a timely fashion, that part of the bone can lose its blood supply and necrose or die. The patient would eventually have to undergo hip replacement surgery.

There is no such thing as a minor dislocation. Joints do not like to be hurt and damage to cartilage, and synovium, the smooth membrane that lines joints, can cause chronic inflammation and perhaps arthritis. Range of motion can be lost. Muscles surrounding the joint can be affected and may weaken in the long run. Chronic instability can occur and the joint can be more prone to dislocate in the future.

The lesson to learn is that each joint in the body has its own quirks that demand attention and it is the potential complication that makes the first responders, paramedics and doctors obsess over whether pulses can be felt or if nerves are working. Appreciating what might be is harder than seeing what is, but it is a reminder that it is always hard to predict the future.

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