Anterior Column Realignment (ACR) With and Without Pre-ACR Posterior Release for Fixed Sagittal Deformity

Abstract

Background: Multiple studies have demonstrated a strong correlation between sagittal malalignment and healthrelated quality of life measures. Thus, correction of sagittal vertical axis (SVA), pelvic tilt (PT), lumbar lordosis-pelvic incidence (LL-PI), and T1 spinopelvic inclination (T1SPi) have become a primary objective of adult spinal deformity surgery. Anterior column realignment (ACR) has emerged as a less invasive technique and while the addition of posterior osteotomies has shown greater correction in ACR, it is unknown if a pre-ACR posterior release is necessary for optimal correction. The purpose of this study was to determine if pre-ACR posterior release allows for greater sagittal deformity correction. Methods: Seventeen patients were identified that underwent minimum 1-level ACR. Ten patients underwent an anterior-posterior surgical sequence without a pre-ACR posterior release, and 7 underwent a posterior-anteriorposterior (PAP) sequence with a pre-ACR posterior release. Radiographic outcomes at final follow-up and complications were compared. Results: Both groups saw significant improvements in LL, LL-PI, PT, SVA, and T1SPi but the correction was not significantly different between cohorts. With the exception of PT in the PAP group, the improvements in LL-PI, PT, and SVA correlated to improvement in Scoliosis Research Society-Schwab classification. The correction achieved at the ACR level, represented by motion segment angle, was greater in the PAP group by a degree that approached statistical significance. Five patients (29%) had 6 complications. Conclusions: Both techniques achieved meaningful improvements in overall sagittal alignment. Our results suggest that a pre-ACR posterior release may allow for greater correction specifically at the ACR level but may not always be necessary to achieve clinically meaningful correction of sagittal plane deformity.

Treatment of late posttraumatic spinal kyphosis with no osteotomy or only posterior column osteotomy based on prone imaging parameters

“…Thus, the technique in the study is not suitable for patients with nerve compression. For patients with rigid or combined anterior nerve compression or kyphosis Cobb angle still over 30° in the prone position, an anterior column osteotomy is required [13,16,24,37], including PSO, VCR osteotomy, etc. Although researchers have re ned these osteotomy techniques [11,12,14], threecolumn osteotomy often decreases spinal stability, and neurological complications, operation time, and complication rates increase.…”

“…In patients with rigid kyphosis, the low mobility of the intervertebral space between the deformed vertebral body and the adjacent vertebral body means that it is impractical to achieve satisfactory deformity correction and sagittal balance by simple posterior column osteotomy [24]. Simple posterior column osteotomies cannot relieve the compression in patients with neurological compression symptoms since the anterior column is the primary source of compression.…”

Anterior column realignment via a minimally invasive hybrid approach in adult spinal deformity surgery: an analysis of radiographic and clinical outcomes

“…To the best of our knowledge, ACR via a minimally invasive hybrid approach has not been previously explored in the literature [10,11]. In this study, we aimed to characterize the radiographic and clinical outcomes of ACR via a minimally invasive hybrid approach in patients with ASD.…”

Anterior column realignment via a minimally invasive hybrid approach in adult spinal deformity surgery: a short-term retrospective study

“…Anterior column realignment (ACR), as an alternative to osteotomy, corrects sagittal imbalance by releasing the ALL and inserting a wedge-shaped intervertebral fusion cage to increase the angle of the intervertebral space [ 11 , 12 ]. To the best of our knowledge, there are no relevant literature to reveal the corrective effects of OLIF and/or ALIF combined with ACR technology on patients with ASD.…”