Current concepts on osteonecrosis of the femoral head

Figure 1 Mechanisms of osteonecrosis.

Figure 2 Left hip anteriorposterior and cross leg lateral X-rays showing (arrows) the crescent sing.

Figure 3 Bilateral osteonecrosis of the femoral head with flattening of the surface and early sings of osteoarthritis.

Figure 4 Magnetic resonance imaging of the left hip showing extensive avascular necrosis of the femoral head with collapse and a large area of devitalized bone demonstrating fibrocystic change. There is associated severe arthrosis of the left hip joint with a moderate effusion, synovitis and debris and a marked bone marrow edema pattern on both sides of the joint.

Figure 5 Core decompression of the left femoral head. Preoperative magnetic resonance imaging, above (coronal and axial views) and fluoroscopic imaging during the procedure below.

Figure 6 Right femoral head osteonecrosis. Flattening of femoral head progression in 24 mo ending up in a right total hip replacement.

Figure 7 Bilateral total hip replacement in a patient with bilateral hip osteonecrosis of the femoral head.

Figure 8 Algorithm for the management and treatment of patients with osteonecrosis of the femoral head. RF: Risk factors; ONFH: Osteonecrosis of the femoral head; FH: Femoral head; MRI: Magnetic resonance imaging; FHCD: Femoral head core decompression; NVBG: Non vascularized bone graft; BA: Biologic agents; VBG: Vascularized bone graft; OA: Osteoarthritis; THA: Total hip arthroplasty.