General Session: MIS-2
Presented by: N. Anand - View Audio/Video Presentation (Members Only)
N. Anand(1), J. Cohen(1), R. Cohen(1), B. Khandehroo(1), S. Kahwaty(1), E. Baron(1)
(1) Cedars Sinai Medical Center, Spine Center, Los Angeles, CA, United States
Introduction: Surgeons use numerous arthrodesis strategies for fusion of the lumbosacral junction including ALIF and AxiaLIF. Nonetheless, the optimal L5-S1 fusion strategy remains inconclusive. The purpose of this study is to compare the fate of the lumbosacral junction in ALIF vs. AxiaLIF patients in terms of clinical and radiographic outcomes.
Methods: This is a retrospective study of 83 patients (mean age 67.3) who underwent circumferential minimally invasive surgical (CMIS) correction of ASD (Cobb angle>20 degrees or SVA>50mm or PI-LL mismatch>10) that underwent AxiaLIF or ALIF with at least 2-year follow-up. Patients were separated into two groups: AxiaLIF (56 pts) and ALIF (27 pts). The groups were compared in terms of segmental lordosis (SL), sagittal vertical alignment (SVA), lumbar lordosis (LL), pelvic incidence-lumbar lordosis (PI-LL) mismatch, as well as, pseudoarthrosis, major complication, and re-operation rates.
Results: The ALIF group achieved significantly greater postop SL (ALIF group: 17.67o, AxiaLIF group: 9.53o), higher delta-SVA (ALIF group: 36.16mm, AxiaLIF group: 5.33mm), higher postop LL (ALIF group: 46.6o, AxiaLIF group: 39.9o), higher delta-LL (ALIF group: 6.35o, AxiaLIF group: .11o), and lower postop PI-LL mismatch (ALIF group: 10o, AxiaLIF group: 16.4o). There was a trend towards lower postop SVA and higher delta-PI-LL mismatch in the ALIF group (Table 1). The pseudoarthrosis, major complication, and reoperation rates trended higher in the AxiaLIF group. Overall, 6 cases of pseudoarthrosis were reported in the entire cohort, 5 of which occurred as a consequence of Axial LIF.
Conclusion: ALIF patients showed more favorable SL and sagittal correction, as well as, a lower trend in rates of pseudoarthrosis, major complications, and reoperations compared to AxiaLIF patients. We propose that ALIF is the preferred strategy for L5-S1 arthrodesis due to these superior radiographic and clinical outcomes.