OUTCOME AFTER SURGICAL TREATMENT OF PRIMARY BONE SARCOMA OF THE THORACIC AND LUMBAR SPINE: 22 CASES

Abstract

Purpose: Malignant primary tumours of the spine require wide resection with preservation of the cord and radicular elements. The purpose of this work was to report our oncological results and complications after spinal surgery for this indication.

Material and methods: Twenty-two patients, mean age 30 years (15–65) underwent surgery. The pathology diagnosis was made preoperatively. There were 16 high-grade tumours, Ewing (n=7), osteosarcoma (n=5), other (n=4), and six low-grade tumours, chondrosarcoma (n=5), osteosarcoma (n=1). Four patients experienced local recurrence after an insufficient initial resection and three required emergency laminectomy. Sagittal hemivertebrectomy was performed in 11 patients for pediculotransverse tumours and total vertebrectomy in 10 patients for corporeal tumours. Posterior fixation was not used in one patient (Ewing tumour) in order to preserve the Adamkiewitz artery.

Results: Complete oncological resection was achieved in 14 patients. The surgical margins were in a malignant zone in 7. At mean 6-year follow-up, ten patients were surviving disease-free (4 Ewing, 4 osteosarcoma, 2 chondrosarcoma), and one was living with active disease (chondrosarcoma). Eleven patients died: metastasis (n=4), local recurrence (n=6), infarction 3 months after surgery (n=1). Among the seven patients with local recurrence,osteosarcoma (n=5),chondrosarcoma (n=2), three had local recurrence at initial management and only one was living at last follow-up (active chondrosarcoma). There were no neurological complications; there were four mechanical complications (nonunion) after total vertebrectomy which required four re-operations.

Discussion: Survival rate in this series was 45% at six years, comparable with rates reported in the literature (40 – 50% at 5 years). Local recurrence was observed in 85% of patients whose surgical margins were in malignant tissue (67–100% in the literature). Among the four patients who had recurrent disease at the time of surgery, complete resection was possible in only one. This patient is living (Ewing sarcoma responding to adjuvant therapy). Incomplete surgery or a poor biopsy procedure aggravates the prognosis. Mechanical failure is observed after total vertebrectomy if anterior osteosynthesis is not associated with the posterior fixation.

Conclusion: Wide surgical resection of primary bone sarcomas of the spine provides encouraging results when the initial operation is successful. Better local control of Ewing sarcoma can be explained by its sensitivity to adjuvant therapy. Reconstruction after total vertebrectomy required anterior and posterior fixation.