Posters— Surgical Treatment of Sarcomas

THE USE OF CEMENTED ALLOGRAFTS FOR RECONSTRUCTION OF SEGMENTAL BONE DEFECTS AFTER TUMOUR RESECTION

Gerrand CH, Griffin AM, Davis AM, Wunder JS, Bell RS, Gross AE (University Musculoskeletal Oncology Unit, Mount Sinai Hospital, Toronto, Ontario M5G 1X5)

Introduction: Sterilization of allograft bone by irradiation may increase the risk of fracture. We routinely reinforce large-segment irradiated allograft bone with pressurized intramedullary cement. The purpose of this study was to review our experience of this technique and the outcomes and complications associated with it.

Methods: The prospectively collected records of all patients who underwent reconstruction of an extremity after tumour resection with a cement-reinforced allograft and potential for three years follow up were reviewed. Results: 39 patients met the criteria for inclusion. The diagnosis was primary bone sarcoma in 25 cases, metastatic disease in 10, soft-tissue sarcoma involving bone in 2, multiple myeloma in 1, and osteofibrous dysplasia in 1. The allograft was intercalary in 17 cases, osteochondral in 14 and used for arthrodesis in 8 cases.

23 patients were alive at a mean of 5.4 years (3.0 to 10.1). 15 patients died at a mean of 2.3 years. One case was lost to follow-up. There were fractures of 3 allografts, 3 became infected and 7 patients required secondary bone grafting for non-union. 5 allografts were removed. There were 2 amputations for local recurrence.

Discussion and conclusion: Intramedullary cementing may improve the mechanical properties of irradiated bone and is associated with an acceptably low fracture rate. If cement is excluded from the graft-host junction and the junction is supplemented with autograft, the non-union rate is comparable or better than that reported elsewhere. Intramedullary cement fixation may be particularly useful with irradiated allografts since cementing likely reduces some of the harmful mechanical effects of radiation.