The potential for pathologic fracture is a common problem associated with metastatic carcinoma or myeloma. These tumors often present as painful osteolytic lesions in the lower limb, with pain on ambulation reflecting significant intrinsic bone weakness. The risk of pathologic fracture in a tubular bone is significant when the tumor occupies 50% or more of the bone diameter or produces a cortical defect longer than 3 cm. Prophylactic surgical stabilization should be considered in patients who are at significant risk for pathologic fracture or who have fractures or painful tumors of the diaphysis that prevent ambulation. Stabilization of most diaphyseal bone tumors is best accomplished with intramedullary rod fixation with or without cementation.

When the tumor is located in the proximal femur or distal femur most of the time the use of a tumor prosthesis that takes the place of the bone involved with the tumor leads to the least rate of failure and earliest mobilization. Destructive tumors in the acetabulum may be treated with curettage and cementation in conjunction with a cage prosthesis and total hip replacement, but the remaining proximal, uninvolved ilium requires careful stabilization. Treatment of symptomatic tumors of the humerus also includes surgical stabilization after tumor removal, preferably with an intramedullary rod.