The Impact of Direct Vertebral Rotation (DVR) on Radiographic Outcome in Surgical Correction of Idiopathic Scoliosis

Abstract

Introduction Recent developments of spinal instruments allow to address nearly all components of idiopathic scoliosis. Direct vertebral rotation (DVR) maneuver was introduced to correct apical axial vertebral rotation. It is however still not well established how efficiently DVR affects results of scoliosis correction. The object of the study was to evaluate en bloc apical vertebral rotation (DVR) and its impact on coronal and sagittal correction of the spine in patients undergoing surgical scoliosis treatment. Materials and methods Thirty-six consecutive patients who underwent posterior spinal fusion with pedicle screws only constructs for idiopathic scoliosis. Fifteen patients (20 curves) were corrected by rod derotation only and 21 patients (26 curves) had both rod derotation and DVR. Curve measurements were performed on x-rays obtained before and postoperatively-coronal curves, kyphosis (T2-T12, T5-T12). Spine flexibility was assessed on prone bending x-rays. Apical axial rotation was determined on CT scans obtained intraoperatively and postoperatively. Rotation angle (RAsag) was measured according to Aaro and Dahlborn. Results We observed reduction of RAsag in all patients; however, in DVR group, decrease was greater, by 31.8% comparing to non-DVR group, by 8.6% (p = 0.0003). Mean coronal correction in DVR group was 68.8% and in rod derotation group without DVR 55% (p = 0.002). No significant correlation was found between degree of derotation obtained and coronal correction. In DVR group T2-T12 kyphosis has increased in 28 (65%) patients whereas in non-DVR group in 31 (69%) cases. Mean value of T2-T12 kyphosis growth was 16.7% in DVR and 22.1% in non-DVR group. These differences however did not occur statistically significant. Conclusions Direct vertebral rotation (DVR) maneuver reduces significantly apical rotation of the spine, enhances ability of coronal correction, and it does not reduce thoracic kyphosis.

Effect of Direct Vertebral Rotation on the Spine Parameters (Coronal and Sagittal) in Adolescent Idiopathic Scoliosis

“…These points can be explained by the DVR technique associated with osteotomy, since when correcting thoracic kyphosis, little change affects the region of the lumbar spine and pelvic segment. These ndings are in agreement with the study by Urbanski et al [21], in which the authors also did not observe signi cant changes in lumbar lordosis, but an increase in thoracic kyphosis with DVR in patients with AIS.…”

“…Using the DVR surgical technique associated with an osteotomy, a 68% correction of the main thoracic curve was observed in the coronal plane, with positive and signi cant improvement. This is similar to that observed in the study performed by Urbanski et al [21], in which the authors evaluated 21 patients who underwent the DVR surgical procedure with researchers observing a 69% correction of the main thoracic curves. However, the divergence among related studies has been debated, especially with regard to sample standardization, surgical correction technique, and xation materials used, as well as standardized surgery time for evaluations.…”

“…Mladenov et al [29] observed a decrease in thoracic kyphosis and lumbar lordosis in patients undergoing DVR compared to patients undergoing simple vertebral defeat. Urbanski et al [21] showed improvement in the coronal plane with the DVR technique, but without differences in the sagittal plane compared to the group of patients submitted to simple defeat. Kim et al [10], evaluating patients undergoing DVR, observed a lower number of arthrodesis and a lesser amount of intraoperative bleeding, despite not seeing signi cant differences in postoperative kyphosis in relation to the control group.…”

Three-Planar Surgical Correction for Adolescent Idiopathic Scoliosis

“…In particular, axial plane correction is achieved thanks to rotating maneuvers that are carried out by extensors attached to pedicle screw heads. There are mainly two types of direct vertebral body rotation, either by using a group of extensors at the apex of the deformity (en-block rotation) or by rotating each level at a time (segmental rotation) [2][3][4][5][6][7]. In this study we describe in a detailed manner a unique technique that combines both these procedures.…”

Could Screw/Hook Insertion at the Apical with Rib Head Dislocation Effectively Retract the Corresponding Rib Head from Spinal Canal in Dystrophic Scoliosis Secondary to Type 1 Neurofibromatosis?

“…However, no particular surgical manipulation was mentioned in the literature to instruct the spine surgeons to effectively obtain more pull-out of the embedded rib head without rib head resection. Usually, adequate apical screw/hook placement along with correction maneuvers can achieve signi cant reduction of vertebral translation and desired vertebral derotation in idiopathic scoliosis [13,14]. For dystrophic scoliosis secondary to NF-1, this concept is supposed to be applicable as well.…”