Examination of Adult Spinal Deformity Patients Undergoing Surgery with Implanted Spinal Cord Stimulators and Intrathecal Pumps

Study Design. Retrospective cohort study of a prospectively collected multi-center database of adult spinal deformity (ASD) patients. Objective. We hypothesized that patients undergoing ASD surgery with and without previous spinal cord stimulators (SCS)/ intrathecal medication pumps (ITP) would exhibit increased complication rates but comparable improvement in health-related quality of life. Summary of Background Data. ASD patients sometimes seek pain management with SCS or ITP before spinal deformity correction. Few studies have examined outcomes in this patient population. Methods. Patients undergoing ASD surgery and eligible for 2-year follow-up were included. Preoperative radiographs were reviewed for the presence of SCS/ITP. Outcomes included complications, Oswestry Disability Index (ODI), Short Form-36 Mental Component Score, and SRS-22r. Propensity score matching was utilized. Results. In total, of 1034 eligible ASD patients, a propensity score-matched cohort of 60 patients (30 with SCS/ITP, 30 controls) was developed. SCS/ITP were removed intraoperatively in most patients (56.7%, n = 17). The overall complication rate was 80.0% versus 76.7% for SCS/ITP versus control (P > 0.2), with similarly nonsignificant differences for intraoperative and infection complications (all P > 0.2). ODI was significantly higher among patients with SCS/ITP at baseline (59.2 vs. 47.6, P = 0.0057) and at 2-year follow-up (44.4 vs. 27.7, P = 0.0295). The magnitude of improvement, however, did not significantly differ (P = 0.45). Similar results were observed for SRS-22r pain domain. Satisfaction did not differ between groups at either baseline or follow-up (P > 0.2). No significant difference was observed in the proportion of patients with SCS/ITP versus control reaching minimal clinically important difference in ODI (47.6% vs. 60.9%, P = 0.38). Narcotic usage was more common among patients with SCS/ITP at both baseline and follow-up (P < 0.05). Conclusion. ASD patients undergoing surgery with SCS/ITP exhibited worse preoperative and postoperative ODI and SRS-22r pain domain; however, the mean improvement in outcome scores was not significantly different from patients without stimulators or pumps. No significant differences in complications were observed between patients with versus without SCS/ITP.