Vascularized Iliac Bone Flap Transfer for Early and Middle Stages of Osteonecrosis of the Femoral Head.

BACKGROUND: Osteonecrosis of the femoral head often affects young active adults and leads to destruction of the hip joint and severe arthritis1-4. Despite improvements in hip arthroplasty design and techniques, it is unlikely that prosthetic replacements will endure for life. Alternatively, various head-preserving procedures have been used to avert or delay the need for a total hip arthroplasty5-11. Vascularized iliac bone flap transfer is a joint-preserving procedure that can be considered for younger patients with early or middle-stage osteonecrosis of the femoral head. DESCRIPTION: The major steps of the procedure include (1) an anterior approach to the affected hip, (2) creation of a bone flap from the iliac crest pedicled with the ascending branch of the lateral circumflex femoral artery, (3) obtaining cancellous bone from the iliac crest, (4) exposure of the anterior aspect of the femoral neck, (5) creation of a 2 × 2-cm window at the junction of the femoral head and neck, (6) debridement and removal of the necrotic bone, (7) implantation of the cancellous bone and vascularized bone flap, (8) fixation of the bone flap, and (9) layer-by-layer wound closure. Complications are rare, and full weight-bearing is allowed at 6 months postoperatively. ALTERNATIVES: Alternatives to the procedure include core decompression, nonvascularized bone-grafting, free vascularized fibular grafting, and vascularized greater trochanter grafting. RATIONALE: Various femoral head-preserving procedures have been reported. Core decompression is an effective femoral head-preserving procedure and is recommended as the first surgical treatment option for symptomatic small to medium-sized precollapse lesions. However, outcomes are poor when a patient has a large lesion or femoral head collapse. The advantage of vascularized iliac bone flap transfer is that it allows femoral head decompression, restores blood supply, and provides structural support. Thus, this procedure can be performed in patients with later osteonecrosis stages before hip osteoarthritis has progressed.