Eighty-four hip revision procedures were performed and treated prophylactically with the adjustable range-of-motion hip-abduction orthosis. Of these, three patients dislocated in an anterior direction (3.5 percent). The three patients' hips were repositioned with closed reduction and controlled after restraining extension and external rotation with a hip-knee-ankle-foot orthosis worn at all times.
Two of these patients were casted into a modified hip spica using the hip-knee-ankle-foot orthosis as a base. The patients wore the orthosis for three months, and neither patient dislocated again after orthosis wear was completed.
Casting tape was used only on patients who dislocated while wearing the orthosis and on those who were suspected of being noncompliant. No patient casted into his or her hip-knee-ankle-foot orthosis dislocated.
Four patients (4.8 percent) dislocated in a posterior direction. Two of these patients discontinued the brace against medical advice and dislocated at four and five weeks. They both had a closed reduction and wore the orthosis 12 more weeks with no recurrence of dislocation. The third patient fell and dislocated his hip after completing orthotic management. He had a closed reduction and remained dislocation-free after 12 more weeks of wearing the hip orthosis. The last patient dislocated the 14th week after orthotic management concluded. This patient had a closed reduction and wore the orthosis 12 more weeks without dislocation. All patients who dislocated were treated with closed reduction and did not require additional surgery.
The records of the seven patients who dislocated were analyzed to determine what characteristics might have predisposed dislocation. Several high risk factors have been identified and are listed in Figure 10