105. ALIF generates better correction of the fractional lumbar curve vs posterior instrumentation alone in spinal deformity fusion to the pelvis

Abstract

BACKGROUND CONTEXT ALIF is a widely accepted strategy to increase lumbar lordosis and improve fusion. It may also help reduce the fractional lumbar curve. Improved fractional curve correction can level the pelvis and facilitate proximal realignment. PURPOSE To determine if the addition of an anterior lumbar interbody fusion (ALIF) to posterolateral fusion results in a more level pelvis by correcting the fractional lumbar curve. STUDY DESIGN/SETTING Retrospective comparative observational cohort. PATIENT SAMPLE Patients undergoing thoracolumbar fusion to the pelvis with S2AI screws for deformity. OUTCOME MEASURES Pre- and postop fractional curve Cobb angle, lumbar lordosis, pelvic tilt, pelvic incidence, sacral slope and percent curve correction. METHODS Patients undergoing thoracolumbar fusion to the pelvis with S2AI screws for deformity were identified and stratified into patients who had an ALIF in addition to PSF (ALIF+PSF) and those who had a posterior instrumented fusion (PSF) only. Radiographic parameters measured included preop and postop fractional curve Cobb angle, lumbar lordosis, pelvic tilt, pelvic incidence, sacral slope and percent curve correction. RESULTS There were 30 cases in the ALIF+PSF group and 31 in the PSF group. Baseline demographic characteristics of the two groups were similar. Mean preop fractional coronal Cobb (18.2° vs 14.2°, p=0.069), lumbar lordosis (30.9° vs 334.2°, p=0.379) and pelvic parameters were similar between the two groups. Postop lumbar lordosis was similar (48.4° vs 44.1°, p=0.183). Greater fractional coronal curve correction was achieved in the ALIF+PSF group (69%) compared to the PSF group (29%, p CONCLUSIONS There is a greater correction of the fractional curve in the ALIF+PSF group compared with the PSF only group. While this may not be the primary indication for ALIF, it is a benefit that may level the pelvis and facilitate overall deformity correction. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.