The elbow is a very complex joint that allows elbow flexion and extension but also forearm rotations called supination (palm up) and pronation (palm down). In order to provide this rotational motion, the top or head of the radius (one of the two bones in the forearm that help form the elbow joint) rolls against the other forearm bone (the ulna.
Damage to the radial head can be very difficult to salvage. Over the years, bone grafting and improved fixation devices like the miniplates have made it possible to preserve more elbows than ever before. And that’s good because implants cannot successfully replace a natural radial head. It’s just such a unique and unusual bone in shape, form, and function.
But sometimes all efforts to stabilize the bones and hold them together until they heal just doesn’t work. In the end, the upper portion of the radius is removed and a prosthetic implant is inserted in its place.
Studies presenting outcomes of radial prostheses report a mix of results from poor to excellent, with equally varying levels of patient satisfaction. The implants are expensive and don’t always fit the patient well. One advantage the prosthetic head does offer is stability when torn elbow ligaments cannot be repaired.
One disadvantage is that overstuffing can occur. This means the implant is too large for the joint space available. Usually it’s a matter of the prosthesis being too long. Over time, the joint cartilage can get worn down and the elbow can start to dislocate. Revision surgery may be needed to correct the problem. Your surgeon will be able to advise you. It may be a case of wait-and-see how things work out for you. But if the loss of motion is disabling, then further treatment may be able to correct the problem.