Osteopetrosis and total hip arthroplasty. Report of two cases.

Two patients with osteopetrosis and osteoarthrosis of the hip underwent "hybrid" total hip replacement. There are technical difficulties in seating acetabular and femoral components on hard and brittle osteopetrotic bone with an obliterated marrow cavity. Although the surgical procedures are challenging, this form of arthroplasty is recommended for hip osteoarthrosis which is associated with osteopetrosis.