Outcomes following Surgical Intervention for Impending and Gross Instability (SINS criteria) Caused by Multiple Myeloma in the Spinal Column

Abstract

Introduction Multiple myeloma is the most common primary tumor of the spine. Spinal multiple myeloma is classically a radiosensitive lesion; however, clinical or radiographic signs of instability merit surgical intervention. The authors present the epidemiology, surgical indications, and outcome data of the largest single series of 31 consecutive surgically treated patients with diagnoses of multiple myeloma and plasmacytoma of the spine. Methods The Spinal Instability Neoplastic Score (SINS) was utilized to make an assessment of surgical instability as the criteria for operative intervention. Patients were analyzed using lesion location, Frankel score, adjuvant therapy, outcome, and survival. Results All patients undergoing surgical intervention had either indeterminate or gross spinal column instability according to SINS criteria. Median survival was 78.9 months. No significant difference in survival was seen for patients with higher SINS scores or for older patients (> 55 years). There was a statistically significant difference in survival benefit observed in patients receiving chemotherapy and radiation versus radiation alone as an adjuvant to surgery ( p = 0.02). Conclusion The report demonstrates outcomes for patients with indeterminate stability and gross spinal instability because of multiple myeloma and plasmacytoma of the spine who underwent surgical intervention with improved neurological function following surgery and low rates of instrumentation failure.