1481. Anterior based correction surgery for adult spinal deformity: An institutional experience

Authors: Muhammad Burhan Ud Din Janjua, MD; Brendan McShane, BA; William Welch, MD; Vincent Arlet; Ali Ozturk, MD (Dallas, TX)

Introduction:

Posterior spinal surgery with Schwab grade II and above osteotomies is considered a standard approach for correction of global malalignment in adult spinal deformity (ASD). Alternative is 560° approaches with major correction in stage or un-staged fashion. Authors aim to assess surgical outcome in ASD patients with use of hyperlordotic cages (HLCs) utilizing anterior based correction.

Methods:

All patients who meet the criteria for ASD were operated from January of 2015 to July of 2018 at a tertiary care center. Standing full-body stereographs were obtained and pre-to-postoperative global sagittal measurements were performed. Radiographic parameters were analyzed including T4-12TK, PT, LL, SS, PI-LL, T1PA, and SVA. Statistical analysis included paired and unpaired t-tests, and logistic regression.

Results:

71 patients (58 years SD ± 12.7, 75% female, mean BMI of 28.3 SD ± 5.8, average follow-up was 353 days) demonstrated significant difference in global sagittal alignment parameters from pre- to postoperative standing: LL (-30.62 º vs. -54.37 º, p<0.001), SS (31.22 º  vs. 38.04 º, p=0.001), PI-LL (28.3 º vs. 8.44 º, p<0.001), T4-12 TK (28.41º vs. 40.5º p<0.001), PT (29.89º vs. 22.85º p<0.001), SVA in mm (86.23 vs. 38.35, p<0.001), T1PA (30.71º vs. 18.70º, p<0.001). Using linear regression analysis, predicted pre- to postoperative change in standing LL corresponded to pre- to postoperative changes in standing PI-LL mismatch (R2= 0.451, p<0.001), T1PA (R2= 0.144, p=0.001), TK (R2= 0.273, p<0.001), SS (R2= 0.155, p=0.001), and SVA (R2= 0.154, p=0.001). 13 (18%) patients had surgical, 23 (32%) medical, and 6 (8%) had neurological complications (50% were transient). 16 (22%) underwent revision operation for minor instrumentation failure.

Conclusion:

Anterior approach utilizing HLCs is equivalent in magnitude to Schwab Grade III osteotomies for correction of global sagittal alignment, however, is associated with significantly less neurological complications, EBL, fast recovery with well documented good outcome.