SURGICAL-MANAGEMENT OF PELVIC AND EXTREMITY OSTEOSARCOMA

Between 60-80% of all patients with osteosarcomas of the pelvis and th e extremities can now he safely treated with limb-sparing surgery. Res ults (as defined by rates of local recurrence, overall survival, and f unction) are equal to or better than those associated with amputation. Successful use of limb-sparing procedures, however, depends on a well -developed surgical plan. An understanding of the biologic behavior an d growth patterns of these lesions is fundamental. Staging of the prim ary tumor must involve a full complement of imaging modalities, includ ing plain radiography, bone scintigraphy, computerized axial tomograph y (CAT), magnetic resonance imaging (MRI), and angiography. The biopsy must be well placed to reduce the possibility of tissue contamination , which is a common reason for amputation. Restaging is necessary befo re surgery for patients who have undergone neoadjuvant therapy; there is recent evidence that preoperative therapy may make limb-sparing sur gery possible in more than 50% of patients who otherwise would have re quired amputation. Relative contraindications to limb-sparing surgery include major involvement of the neurovascular bundle, pathologic frac ture, inappropriate biopsy site, infection, immature skeletal age, and extensive muscle involvement. Each of these factors is relative, and patient selection decisions must be made on an individual basis. Limb- sparing surgery consists of the following three phases: tumor resectio n, skeletal reconstruction, and soft tissue and muscle transfers. The range of reconstruction techniques has been broadened by developments in bioengineering. Among the more commonly used techniques are custom endoprostheses and allograft replacements. Future progress in inductio n regimens and reconstructive techniques will undoubtedly enable limb- sparing surgery to be a satisfactory alternative to amputation in even more patients.