Do vertebral derotation techniques offer better outcomes compared to traditional methods in the surgical treatment of adolescent idiopathic scoliosis?

Abstract

In recent years, authors have described novel derotation techniques for surgery in adolescent idiopathic scoliosis. These methods include direct vertebral body derotation (DVD) and vertebral coplanar alignment (VCA). By improved derotation it is hoped that there is further reduction in rib hump prominence and corresponding improvement in patients' quality of life. This paper aims to evaluate studies reporting outcomes from DVD and VCA techniques to assess if these methods lead to superior radiographic vertebral derotation, rib hump correction on surface measurements or patient-reported outcomes compared to traditional derotation manoeuvres using similar instrumentation. Literature review. Fifteen reports were identified. Most comparative studies represent class three or four data. DVD and VCA techniques have been shown to reduce apical vertebral rotation by 37-63 %. Few studies compare DVD/VCA techniques with traditional methods. Most DVD/VCA reports with pedicle screw instrumentation have reported superior radiographic derotation on CT compared with conventional techniques. Despite this the majority of studies have found similar corrections of rib hump measurements between DVD/VCA techniques and cantilever or global derotation methods. There is no evidence that DVD/VCA techniques allow greater correction of significant rib hump deformity without an adjuvant thoracoplasty. No studies to date have used patient-reported outcomes prospectively or demonstrated clinically meaningful differences retrospectively between DVD/VCA and conventional techniques. There is little evidence to recommend the widespread adoption of DVD/VCA techniques. Whilst there is some weak evidence to suggest that novel techniques may improve radiographic measures, there is little to suggest that they offer patients improved correction of clinical rib hump or quality of life compared to established techniques. Further well-designed prospective studies are needed in this area.