The patient

A 31-year-old otherwise healthy man presented with an enlarging and increasingly symptomatic left posterior ilium tumor. Biopsy revealed high grade osteosarcoma. Additional staging studies demonstrated no distant metastases. He was treated with neoadjuvant MAP chemotherapy (methotrexate, Adriamycin, cisplatin).

The challenge

Pelvis osteosarcomas have lower overall survival than those of the extremities. Positive surgical margins and local recurrence are also more common at this site due to the complex anatomy of the pelvis and proximity of critical neural, vascular and visceral structures. Typically, the most reliable method of resection for this tumor is removal of an entire segment of the pelvic ring, which can result in chronic limb length discrepancy, pelvic instability and pain. Complex reconstructions with metal instrumentation and bone grafts are frequently employed to address the resultant instability. With standard fluoroscopic intraoperative imaging, the risk of violating the tumor during a complex biplane osteotomy required to maintain pelvic ring continuity would be high.

The provider

George T. Calvert, M.D., orthopedic oncologist and orthopedic surgeon with Norton Orthopedic Institute

The solution

Preoperative cross-sectional imaging was used to plan a biplane osteotomy that would both avoid tumor violation and preserve pelvic ring continuity. At surgery, wide soft tissue dissection was performed around the margins of the tumor exposing uninvolved bone. A metal fiducial tracker was then attached to the pelvis distant from the tumor site and intraoperative CT scan obtained. Computer navigation then matched the images to surgical drills, chisels and burs, permitting live image guidance of the bone cuts. These were carried out in accordance with the preoperative plan. Pelvic continuity was maintained and surgical margins were negative.

Image shows preoperative CT scan with planned osteotomies marked.

The result

The patient was weight-bearing as tolerated immediately postoperatively. He was able to discharge to home rather than a rehabilitation facility in six days after major pelvis surgery. He had no wound healing issues despite lengthy surgery and initiated adjuvant chemotherapy on schedule. At two years from surgery, he has no evidence of recurrence and is walking without assist device.

Image shows remodeling at the osteotomies without evidence of recurrence 21 months after surgery.

Treatment and results may not be representative of all similar cases.