Outcomes of Posterior Instrumentation in Multiple Myeloma: A Seven-year Retrospective Study

Introduction: Multiple myeloma (MM) is the most common primary malignancy of the adult spine. Though radiosensitive, it can result in neurological impairment or spinal instability, necessitating surgical intervention. This study looks at the epidemiology, surgical indications, and outcomes of 30 patients with MM of the spine operated at a single center over a seven-year period, along with the relationship between preoperative serum albumin levels and postoperative hospital stay and complications

Methods: The study selected 30 patients who underwent posterior instrumentation for multiple myeloma from January 2016 to July 2023. Details such as biodata, comorbidities, ASA class, functional status, surgery level, postoperative complications, and mortality were analyzed. Pre-operative serum albumin, creatinine, WBC count, and platelet count were also collected and compared with post-operative length of stay.

Results: Of 30 patients with a mean age of 56.77 ± 10.07 years, 19(63.33%) were male, 2(6.67%) were classified as ASA class 1, 24(80%) as class 2, and the rest were ASA class 3. As for functional status, 1 patient (3.33%) was independent, 24(70%) partially dependent, and 4(13.33%) completely dependent. Postoperatively, 28 patients were independent. The mean follow-up period was 39.63 months. 6 patients had unplanned readmissions within 6 months. At the final follow-up, 3 patients (10%) expired, and 2(6.67%) underwent reoperation. The average length of stay was 12.74 ± 8.99 and 10 patients (33.33%) were hypoalbuminous pre-operatively; with no significant difference in hospitalization length between hypoalbuminous and normal patients or between patients with higher and lower SIN scores. There was a statistically significant difference in length of stay observed in older patients (>55 years) (p = 0.044).

Conclusion : In this 7-year study, we report the outcomes of patients with MM who underwent posterior instrumentation for spinal instability. These patients showed functional improvement and reduced complication rates, with no significant correlation between pre-operative albumin and hospitalization length.