P129. Outcome analysis of expandable cage use in transforaminal lumbar interbody fusions

Abstract

BACKGROUND CONTEXT Expandable cages (EXP) are more frequently utilized in Transforaminal Lumbar Interbody Fusions (TLIF). Designed to reduce complications related to neurological retraction, enable better lordosis restoration, and improve ease of insertion, particularly in the advent of minimally invasive techniques they are exponentially more expensive than the non-expandable (NE) alternate. PURPOSE To investigate the value of expandable cages given the significantly higher cost. STUDY DESIGN/SETTING Retrospective review at a single institution. PATIENT SAMPLE A total of 257 TLIFs between 2012 and 2018 were included. OUTCOME MEASURES Clinical characteristics, perioperative and neurologic complication rates and radiographic measures. METHODS Patients ≥ 18 years of age who underwent single-level TLIF with minimum 1-year follow-up were included. Outcome measures: clinical characteristics, perioperative complications and neurologic complications. Radiographic analysis included change in pelvic incidence-lumbar lordosis (PI-LL), segmental lumbar lordosis (LL), and disc height restoration. Subsidence was radiographically assessed at 1-year follow-up from intraoperative imaging for breaching of the vertebral endplates, measured from the cage endplate to vertebral endplate and defined as a >2mm. Statistical analysis included independent t-tests and chi-square analysis with significance set at p RESULTS A total of 257 TLIFs between 2012 and 2018 were included, with 155 NE (53.5% female, mean age 59.46±14.07, mean BMI 28.69±5.39) and 102 EXP (49% female, mean age 57.78±11.76, mean BMI 28.72±6.01) with no significant differences in demographics. There were significantly more MIS TLIF cases and BMP use in the EXP group (88.2% MIS, p CONCLUSIONS Once technique was controlled for, TLIFs utilizing EXP do not have significantly different neurologic or radiographic outcomes compared to NE. These results question the value of EXP given the higher cost. The findings require further direct comparison in the MIS population because the benefit on outcomes compared to the alternate remains controversial due to the bias towards increased use in MIS procedures. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.