70. Anterior column realignment (ACR) performed at L2-3 achieves suboptimal lumbo-pelvic realignment compared with L2 pedicle subtraction osteotomy (PSO)

Abstract

BACKGROUND CONTEXT The anterior column realignment (ACR) technique is increasingly becoming popular for treating patients with flatback deformity. The degreed of correction achieved with ACR performed at L2-3 disc has not been well studied. PURPOSE The purpose of this study was to compare the degree of deformity correction and perioperative outcomes between ACR and PSO being performed at L2 for iatrogenic flatback deformity. STUDY DESIGN/SETTING Retrospective review. PATIENT SAMPLE N = 27 patients, 9 ACR and 18 PSO. The patients were matched 1:2 (ACR:PSO) based on preoperative deformity parameters. OUTCOME MEASURES Primary outcome: Lumbo-pelvic parameters (LL-PI mismatch, SVA, PT). Secondary outcomes: estimated blood loss, transfusion requirement, length of hospital stay, operative time, postoperative complication, and hospital readmission rates. METHODS Patients were identified between 2012 and 2016 who underwent revision surgery using either the PSO or ACR technique at the L2-3 level to correct sagittal deformity. Patients who underwent ACR were matched to PSO patients in a 1:2 fashion based on preoperative lumbar lordosis (LL) and lumbar lordosis pelvis incidence (LL-PI) mismatch. Patient demographics, surgical variables, pre- and postoperative radiographic parameters, and perioperative characteristics were compared between the treatment groups using t-tests, chi-square tests, and multivariable regression models. RESULTS The cohort included 27 patients; 9 ACR patients matched to 18 PSO patients. The PSO group achieved a greater degree of lumbar lordosis compared to the ACR group (31° vs 14.23°, p CONCLUSIONS PSO surgery resulted in significantly improved lumbar lordosis and sagittal alignment correction compared to the ACR group. While ACR resulted in some improvement of lumbar lordosis, it resulted in residual lumbo-pelvic mismatch compared with patients treated with PSO. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.