170. Radiculitis: assessing the risk of biologic use in minimally invasive transforaminal lumbar interbody fusions

BACKGROUND CONTEXT Recombinant human bone morphogenetic protein 2 (BMP) is increasingly utilized in minimally invasive (MIS) transforaminal lumbar interbody fusions (TLIF) in order to increase rate of fusion by promoting bone growth through the induction of osteoblast differentiation, awhile reducing morbidity related to iliac crest autograft. Despite these benefits, BMP use is still controversial due to its pro-inflammatory mechanism of action and potential to cause radiculitis. PURPOSE To assess whether BMP is a risk factor for postoperative radiculitis in TLIF. STUDY DESIGN/SETTING Single-center retrospective cohort study. PATIENT SAMPLE A total of 397 TLIFs from June 2012 to December 2018. OUTCOME MEASURES Perioperative clinical characteristics, post-operative risk of radiculitis and complication, and future reoperation rates. METHODS Patients ≥ 18 years-old undergoing elective single-level TLIFs from 2012 to 2018 were included. Outcome measures included perioperative clinical characteristics, postoperative risk of radiculitis and complication, and future reoperation rates. Radiculitis was defined the delayed onset of radicular symptoms postoperatively in patients whom had initial resolution of radicular symptoms immediately postoperatively, in the absence of persistent neurological compression on postoperative imaging. Statistical analyses included independent t-tests and chi-square analysis. Propensity score matching was utilized to control for demographic differences between the groups. Independent predictors for post-operative radiculitis were assessed by multivariate logistic regression. Significance set at p RESULTS A total of 397 cases were included in the study (59.33 ± 13.49 mean age, 28.98 ± 6.29 mean BMI, 52.90% female, 2.29 ± 1.92 average Charleston comorbidity Index). There were 223 open procedures and 174 MIS. For the entire cohort, 238 cases utilized BMP and 159 did not, with 102 MIS pairing with BMP use. The MIS TLIFs had a higher percentage of BMP use than open TLIFs (58.6% vs 25.7%, p CONCLUSIONS While BMP and MIS technique were not independent risk factors for postoperative radiculitis, there is an increased risk of radiculitis when using BMP in MIS TLIF. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.