Pelvic osteosarcoma. Resection, reconstruction, local control, and survival statistics.

Nine patients with a malignant tumor in the periacetabular region of the pelvis were treated with a Type IIC resection and were reconstructed using a cementless, adaptable prosthetic system. In two patients, a new planning strategy was applied using three-dimensional reconstruction. There were two chondrosarcomas, three Ewing-sarcomas, two osteosarcomas, and two metastases of thyroid cancer. Excision was wide, marginal, and intralesional in three cases each. Ages ranged from eight to 68 years (average, 40 years), and follow-up periods ranged from 12 to 36 months with an average of 27 months. Overall functional evaluation was good in five cases, fair in three, and poor in one. Four patients died of local recurrences and lung metastases; all of them had marginal or intralesional resections. Histologic analysis of one retrieved specimen revealed bone ingrowth with connective tissue interface. Three-dimensional planning has proven to be a very valuable tool for achieving an anatomic reconstruction of the pelvic ring. These results are encouraging and endorse the authors to continue with the current approach of prosthetic reconstruction following Type IIC resections.