[Evaluation of surgical treatment of pelvic osteosarcoma]

To investigate the clinical outcome of consecutive pelvic osteosarcoma treated with surgery and chemotherapy in a single institution, and to discuss the surgical strategy, resection and reconstruction.

Twenty-one consecutive cases with pelvic osteosarcoma underwent surgical procedures between June 2000 and June 2009. There were 12 male and 9 female with a mean age of 32 years. According to Enneking and Dunham pelvic classification system, type Iwas 3 cases, type I+IV 3 cases, type I+II 4 cases, type II+III 4 cases, type I+II+III 1 case, type III 1 case, and type I+II+IV 5 cases. Among the 21 cases, 19 were diagnosed as classical osteosarcoma and 2 were diagnosed as low-grade pathologically. All the tumors were stage IIB. All the patients received en-bloc resection with 13 wide resection and 8 marginal resection. Thirteen patients underwent modular hemi-pelvic endoprosthesis reconstruction, and 5 patients underwent rod-screw system reconstruction combined with autograft. Two patients received hemipelvectomy and one type III patients had resection without reconstruction. The mean follow-up period was 30.3 months (range, 6.0-87.0).

Thirteen patients out of 21 survived after treatment. The overall survival rate was 61.9%, and 23.8% patients were alive without disease. The estimated 5-year survival rate was 44.2% based on Kaplan-Meier curve. The local recurrence rate was 28.6%, among which 4 cases were type II resection, 1 was type I resection, 1 was type I+IV resection.No local relapse was found on the hemipelvectomy and type III resection cases. The local recurrence rate after wide resection was 23.1%, and 37.5% for marginal resection.Nine patients had lung metastases and one patient was found bone and lymph node metastases. The MSTS 93 function score was 20.6 ± 5.4 for 13 patients, and 22.5 ± 2.1 for rod-screw reconstruction cases. The function score was 17.7 ± 5.5 for hemi-pelvic prosthetic reconstruction.

Limb salvage procedures could be performed on most pelvic osteosarcoma cases, and satisfying function outcome could be achieved with proper reconstruction, however, the overall survival is still lower compared with those in extremities.