OUTCOME OF RADIATION-INDUCED PATHOLOGIC FRACTURES AFTER SURGERY FOR SOFT TISSUE SARCOMAS

Abstract

Radiation induced pathologic fractures present a difficult problem for musculoskeletal oncologists. The purpose of this study was to determine the outcomes of management of radiation-induced pathologic fractures in a group of patients who had previously undergone combined management of extremity soft tissue sarcoma.

A review of our retrospective database was undertaken. From 1986 to present, thirty-two patients with soft tissue sarcomas were found to have radiation induced pathologic fractures. The records of these patients were reviewed for patient demographics, tumour size and anatomic site, presence of periosteal stripping at time of surgery, radiation dose, time to fracture, fracture treatment and fracture outcome.

There were twenty-three females and nine males with a mean age of sixty-three (range thirty-six to eighty-nine) years. Fractures occurred at a mean of forty-five months after resection of the sarcoma (range three to one hundred and fifty months). Anatomic distribution of fractures were : proximal femur(twelve), femoral diaphysis (eight), distal femur (two) tibia (five), acetabulum (two), metatarsal (two) and patella (one). Periosteal stripping was performed in half of the patients. Twenty-three patients had received high dose radiation (6600Gy). Seven fractures were managed conservatively while twenty-five were treated surgically. Only eleven of the thirty-two fractures united. Six patients underwent amputation, three for local recurrence and three for non-union of their fracture. Eight patients ultimately underwent arthroplasty, while seven patients have persistent non-unions. In the proximal femur, only three out of twelve fractures healed while six patients eventually underwent arthroplasty and three continue to have non-unions. Of eight femoral diaphyseal fractures, only one united. Patients who eventually underwent prosthetic replacement had good function and pain relief.

Radiation induced pathologic fractures are a difficult clinical problem. In particular patients with fractures in the proximal femur often undergo multiple attempts at fixation before definitive management with resection and endoprosthetic replacement. Fractures of the femoral diaphysis rarely heal despite aggressive surgical management. Primary arthroplasty may be considered in some patients as an alternative to fixation in radiation-induced pathologic fractures of the femur in order to avoid long term morbidity and repeated operations.