1463. A Retrospective Review of Transforaminal Lumbar Interbody Fusion Patients Treated with Expandable and Static Spacers

Authors: Adam Kremer; Jefferson Alferink; Stacie Wynsma; Torrey Shirk, BA; Saif Khalil, PhD; Charles Ledonio, MD (Holland, MI)

Introduction: Interbody spacers for transforaminal lumbar interbody fusion (TLIF) offer favorable clinical results. Expandable devices allow in situ expansion to optimize fit and mitigate iatrogenic endplate damage occuring during trialing/impaction seen in static devices. This study compared clinical/radiographic outcomes between static and expandable spacers following TLIF. Methods: A retrospective chart review from a single site was performed on 99 patients undergoing TLIF using one of two interbody spacers. Forty-eight patients received a static peek interbody spacer; the remaining 51 received an expandable titanium interbody spacer. Surgical data, Oswestry Disability Index (ODI), and Visual Analog Scale (VAS) scores were collected/analyzed. Radiographs were collected/measured when available. Complications were compared using Fisher’s exact test. Results: Patients treated with expandable spacers had significantly (p<0.05) less blood loss (81.7cc vs. 36.2cc) and shorter hospital stays (2.2 vs. 1.4 days). Operating room time was lower for patients treated with expandable spacers than static spacers (130.6 vs. 149.5 minutes), although this difference was not significant (p=0.07). At 3-month and final follow-up, expandable implants patients had significantly lower ODI scores than static implant patients (p<0.05, 14.4, and 22.6, respectively). Disc/neuroforaminal height increased significantly (p<0.05) from baseline at 3-month follow-up for both interbody spacers, although the expandable group had significantly greater neuroforaminal height (22.3 vs. 20.1 mm). There was significant (p<0.05) difference in complication rates between static and 2% for expandable group. By standard of care, only patients reporting recurrence of low back pain had to follow-up with surgeons past 3 months postoperatively. Only 3 of 51 (6%) expandable patients had to follow-up at >24 months, compared to 12 of 48 (25%) static patients. Conclusion: Patients treated with expandable interbody fusion spacers used in a transforaminal approach demonstrated significantly less blood loss, shorter staya, lower ODI scores, and significantly fewer complications at final follow-up than static spacer patients.