96. Superior facet joint violations in single-level minimally invasive vs open transforaminal lumbar interbody fusion: prospective comparative study

Abstract

BACKGROUND CONTEXT Facet joint violation (FV) was reported as variable iatrogenic damage that can be a crucial risk factor leading to the adjacent segment degeneration (ASD) in index open and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) performed for various lumbar degenerative indications.“Blind” screw placement technique in minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) contributes to the increasing incidence of FV that can be influenced by several potential factors. Previous studies have evaluated facet joint violations in open or percutaneous screw cases, but there are no reports describing a direct institutional and single lumbar level comparison. PURPOSE Objective: To compare the incidence of superior joint facet violation for open vs percutaneous pedicle screws at a single lumbar level and to evaluate patient and surgical factors that impact this outcome. STUDY DESIGN/SETTING We prospectively analyzed 200 cases undergoing single-segment MIS-TLIF and open TLIF for degenerative lumbar spine disease with stenosis with or without spondylolisthesis. We used a CT grading system which represents progressively increasing grades of facet joint violation. Patient and surgical factors like gender, age, body mass index (BMI), top-screw level, and depth of spine were analyzed in both groups to determine their impact on facet violation. Moreover, visual analog scale (VAS), and Oswestry Disability Index (ODI) scores were assessed in both groups pre- and postoperatively. PATIENT SAMPLE Our cohort consisted of 100 open patients and 100 percutaneous cases. RESULTS Percutaneous procedures had a higher overall violation grade (p=0.018) and greater incidence of high-grade violations (p=0.0059) compared to open procedures. Bivariate analysis showed significantly greater violations in percutaneous cases for age CONCLUSIONS This study demonstrates greater facet violations for percutaneously placed pedicle screws compared to open at single-level lumbar procedures. MIS-TLIF is an effective treatment for lumbar degenerative disease, but FV occurred at a higher incidence. Facet joints should be protected in MIS-TLIF to avoid ASD. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.