Surgical management of spinal and sacral osteosarcoma: a retrospective single-institution case series

Primary osteosarcoma of the mobile spine and sacrum is a rare and aggressive tumor pathology, accounting for 3%-5% of osteosarcomas and approximately 10% of primary spinal tumors. Limited evidence based on case series is present to guide clinical treatment based on current advances in Enneking-appropriate (EA) resection and multimodal techniques. This study updates the authors' institutional experience, characterizing current management strategies and outcomes in spinal and sacral osteosarcomas.

The authors retrospectively reviewed the medical records of all patients treated surgically for primary spinal and sacral osteosarcoma at a tertiary spine care center from 2015 to 2025. Preoperative demographic characteristics, tumor characteristics, surgical variables, and neoadjuvant/adjuvant therapies were collected. Resections were classified as EA or Enneking-inappropriate (EI). Neurological and oncological outcomes were assessed at short-term (≤ 4 months), intermediate (4-12 months), and long-term or last (> 12 months) follow-up. Primary endpoints were local recurrence-free survival (LRFS) and overall survival (OS).

Twenty-two patients underwent resection. Wide or marginal resection was achieved in 15 patients (68%). Neoadjuvant chemotherapy and radiotherapy were administered to 82% and 27% of patients, respectively. At a median (range) follow-up of 9.1 (0.9-191.0) months, 12 patients (54.5%) had died. Local recurrence occurred in 40.9% of patients and distant metastasis in 31.8%. Multivariable analyses showed significantly higher OS after EA resection (p = 0.026). Additionally, older age, other histological subtypes, and mobile spine locations were independently associated with worse OS.

Despite aggressive multimodal therapy, spinal and sacral osteosarcomas carry high rates of recurrence and mortality. EA resection improved survival in univariate and multivariable models, reflecting the influence of surgical margins on improved prognosis. These findings support pursuing wide resection when feasible while underscoring the need for multicenter collaborations to refine prognostic models and explore novel systemic therapies.