Massive allograft-prosthetic reconstruction of the proximal femur during revision total hip arthroplasty has yielded successful early results in cases of severe bone deficiency; however, recommendations differ as to the type of prosthesis to be employed and the method of achieving rigid fixation of the allograft. In regard to the bony configuration at the allograft-host junction, a step-cut osteotomy, a transverse osteotomy, and an oblique osteotomy have all been reported. A case is presented in which fracture of the host femur occurred distal to a step-cut osteotomy in osteoporotic bone.