Resection arthrodesis of the knee for osteosarcoma: an alternative when mobile joint reconstruction is not feasible.

BACKGROUND Wide resection and mobile joint reconstruction are preferable for treating an osteosarcoma around the knee. In certain situations, resection arthrodesis or an amputation is suggested. METHODS During the past decade, 86 patients with an osteosarcoma around the knee were treated surgically in our institution. Wide resection and endoprosthetic reconstruction were performed in 35 patients, resection arthrodesis was performed in 36 patients, and an amputation was performed in 15 patients. The oncological and functional results were compared. Special attention was paid to the indications, techniques, and complications of patients receiving resection arthrodesis. RESULTS Extensive tumor involvement was the main reason, followed by inappropriate previous treatment, for precluding mobile joint reconstruction. The local recurrence rates were similar among the 3 groups (11.4% for the endoprosthetic group, 11.1% for the arthrodesis group, and 6.7% for the amputation group). The 5-year survival rate was 39% for the arthrodesis group, which was significantly lower than that of the endoprosthetic group (60%, p = 0.040), although it was higher than that of the amputation group (13%, p = 0.056). Major complications were found in 7 patients receiving resection arthrodesis (7/24, 29%), and these included nonunion, infection, and allograft fracture. Functional results for the arthrodesis patients were inferior to those of the endoprosthetic patients, but most patients were grateful for preservation of the limb despite certain handicaps. CONCLUSIONS The importance of early and proper planning of treatment cannot be over-stressed when treating osteosarcomas. Resection arthrodesis offers a durable reconstruction alternative to amputation in a special group of patients when extensive resection precludes mobile joint reconstruction.