Impending pathologic fractures from metastatic malignancy: evaluation and management.

Both lytic and blastic long bone metastases are at risk to develop pathologic fractures in instances where more than 50% of the circumferential cortical bone has been destroyed or where the pain with weight-bearing stresses persists, increases, or recurs despite adequate local irradiation. Moreover, those most commonly encountered lesions of the proximal femur are at high risk to fracture if they are in excess of 2.5 cm in any dimension or if they are associated with avulsion of the lesser trochanter. Such lesions should be treated aggressively by prophylactic internal fixation. This will avoid the development of a secondary fracture with its concomitantly high risk that true bony healing will not occur even with adequate fixation. When internal fixation is chosen for a large metastasis with extensive cortical destruction, that fixation should be augmented by debulking of the lesion and by packing it with methylmethacrylate polymerizing in situ. Such an expedient not only improves the efficacy of subsequent radiotherapy but also prevents shortening of the bone with weight bearing while enhancing the torque capacity and sheer resistance inherent in the metal fixation device.