Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P84. Transforaminal versus anterior lumbar interbody fusion at L5-S1 in MIS treatment of ASD: effect on spinopelvic parameters and outcomes in degenerative scoliosis

Abstract

BACKGROUND CONTEXT The surgical treatment of adult spinal deformity (ASD) presents a multifaceted challenge to restore sagittal balance, obtain fusion, and optimize patient outcomes. Two approaches to arthrodesis at the lumbosacral junction have demonstrated high rates of fusion with satisfactory outcome: anterior lumbar interbody fusion (ALIF) and transforaminal lumbar interbody fusion (TLIF). Each technique has advantages and disadvantages regarding approach, sagittal alignment, and neural decompression. There is a paucity of evidence directly comparing clinical and radiographic outcomes of these two techniques in the context of ASD surgery. PURPOSE Anterior lumbar interbody fusion versus TLIF at the lumbosacral junction during MIS correction of ASD result in different radiographic and clinical outcomes. STUDY DESIGN/SETTING Retrospective multicenter cohort study. PATIENT SAMPLE A total of 223 patients were identified in a retrospective ASD database with minimum 2-year follow-up. 82 patients underwent either TLIF or ALIF at the lumbosacral junction. OUTCOME MEASURES Radiographic, clinical and surgical parameters were compared. METHODS A total of 223 patients were identified in a retrospective ASD database with minimum 2-year follow-up. A total of 82 patients underwent either TLIF or ALIF at the lumbosacral junction. Each group had similar demographic & deformity characteristics. Mutlivariate analysis was used to control for preoperative differences between the two groups. RESULTS Mean follow-up was similar between groups [36.7 months (ALIF) and 39.1 months (TLIF) (p=.51)]. No differences in EBL (ALIF:793.7vs. TLIF:1246.2ml, p=.184) or total OR time (566.9vs. 559.9 minutes, p=.9). There was no difference in preop spinopelvic sagittal parameters. Post-op there was greater LL with ALIF than with TLIF (49.7° vs. 40°, p=.015), but no significant differences in other spinopelvic parameters including PI-LL and change in LL. Major complications (COMP) occurred with similar rates after ALIF (16.7%) and TLIF (28.8%; p=.166), but minor COMP occurred more frequently after TLIF than with ALIF (53.8% vs. 30%; p=.037). Infection was more common after TLIF (15.4% vs. 0%, p=.024) as were implant COMPs (26.9% vs. 3.3%, p=.008). In ALIF 1 patient had rod fracture and screw loosening. TLIF had three rod fractures, 8 interbody migration, one subsidence, three screw breakages, and one screw malposition. Reoperation was required with similar frequency (10% ALIF vs. 26.9% TLIF; p=.069). ALIF reops were all for PJK, while TLIF required 11 reops for implant COMPs and one implant related revision for ALIF (p=.028). CONCLUSIONS In this study, both ALIF and TLIF at the lumbosacral junction resulted in similar HRQoL, total operative time and EBL. ALIF resulted in greater LL, but no additional differences in radiographic outcomes. The use of ALIF resulted in fewer minor complications than TLIF when performing MIS correction of ASD. ALIF at the lumbosacral junction was also associated with fewer implant-related complications and reoperations when compared to TLIF.