Correction of adolescent idiopathic scoliosis using the convex rod de-rotation maneuver: a systematic review

Abstract

Background: Adolescent idiopathic scoliosis (AIS) is a spinal deformity affecting 2-3% of the population, predominantly girls. Standard treatment involves posterior spinal fusion (PSF) with pedicle screws, which, despite being effective, carries risks of complications from screw misplacement. Convex single-rod de-rotation techniques have recently emerged as promising correction maneuvers. This review aims to evaluate their safety and effectiveness.

Methods: A systematic review adhering to PRISMA guidelines was performed. Literature from PubMed/MEDLINE, SCOPUS, CINAHL, EMBASE, and CENTRAL up to July 2023 was analyzed. The included studies comprised AIS patients treated with the convex rod de-rotation technique, assessing pre- and postoperative major curve angles and thoracic kyphosis using the Cobb method, percentage of curve correction, loss of correction, and perioperative complications.

Results: Of 661 studies initially identified, 11 met the inclusion criteria, involving 511 AIS patients (mean age 15.02 years) treated with convex rod de-rotation. The average follow-up period was 33.1 months. Curve magnitudes ranged from 41.9° to 110°, with a mean correction rate of 73% (43.5%-89%). Thoracic kyphosis ranged from a mean value of 21.3° (range 10-74) before treatment to a mean value of 26.2° (range 6-49) at the final follow-up. No significant complications were reported.

Conclusion: The convex rod de-rotation technique offers substantial curve correction with minimal complications. Nevertheless, additional studies are needed to standardize surgical protocols and validate long-term outcomes. Limitations such as small sample sizes and methodological variability underscore the need for further research to confirm these findings and refine the approach.

Keywords: AIS; Adolescent idiopathic scoliosis; Concave; Convex rod; Convex rotation; Curve correction; Spinal deformity; Spinal fusion.