Osteonecrosis of the femoral head after traumatic hip dislocation in the adult.

Osteonecrosis of the femoral head is most commonly classified according to the system of Ficat and Arlet, and the choice of treatment is based directly on the corresponding stage. Therefore it is important to accurately determine the stage of the disease because it has important bearings on the patient's clinical course. Patients with Stage I lesions (preradiologic stage of the disease) usually can be treated with pulsed electromagnetic fields with or without a core decompression, bone grafting and decompression, and rotational intertrochanteric osteotomy. These procedures are equally applicable for patients with Stage II lesions but frequently additional measures such as vascularized fibular grafting and intertrochanteric osteotomy may be necessary. Patients with Stages III and IV lesions also may be treated in a similar way, especially if one wishes to avoid total hip arthroplasty, especially in younger patients. The trapdoor procedure with autogenous cancellous bone and cortical bone grafting can be successful in Stage III osteonecrosis of the hip in patients with small- to medium-sized lesions. When core decompression is used to treat patients with Stage III lesions, an 89% satisfactory outcome can be expected providing that the lesion is small and central, and does not have head depression. Many times the number and variety of procedures tend to reflect the relatively poor results and the desire to avoid total hip arthroplasty. Arthrodesis continues to be an excellent and predictable treatment option and may be indicated when unilateral trauma is the etiology.