The ball and socket joint, formed by the acetabulum and the femoral head, refers to the hip. A joint with excessive mobility, usually due to paralysis of the muscles that control it, refers to a flail joint. In this case, the hip is involved.

Excessive mobility of a hip joint may be caused by an infected, failed joint replacement; chronic osteomyelitis; muscle paralysis; muscle deterioration; or lack of nerve supply (denervation).

There is excessive joint mobility and associated pain with a flail joint. An abnormal walking will be apparent, and a possible discrepancy in leg lengths will be present.

Physical examination; x-rays; computed tomography (CT) scan; magnetic resonance imaging (MRI); electromyography (EMG); and nerve conduction tests may be used as diagnostic tools.

Treatments may consist of medications for infection; braces; physical therapy; or operative repair to restore the joint to the highest level of function.

There may be ongoing impaired mobility and limited activities of daily living (ADL).

• None.

• Evaluate under diagnostic codes 5256, 5257, 5260, or 5261 for the knee, or 5250-5254 for the hip, whichever results in the highest evaluation.