Apical control in the management of severe early-onset scoliosis

The three-dimensional apical deformity of scoliosis, comprised of apical vertebral rotation and translation into the convex hemithorax, is believed to be an important anatomic factor responsible for respiratory morbidity associated with poorly controlled EOS. Current “growth-friendly” techniques, such as distraction-based spine constructs, are known to have limited ability to control or correct this apical deformity by virtue of spine anchors being limited to end-vertebral segments only and the biomechanical limitations of pure distraction on a three-dimensional deformity. As a result, methods to improve apical control of EOS (e.g., growth-guidance methods [Shilla, modern trolley]) are now more commonly part of the treatment armamentarium. An additional technique, combining apical control with conventional growing rod methodology, is described in this chapter. Serial correction of spine penetration by in situ bending and re-contouring of an apically anchored convex rod combined with standard lengthening is described. Preliminary results in a small, single institution series are encouraging, by demonstrating improved symmetry between concave and convex hemithoraces on imaging studies while permitting continued spine and thoracic volume growth.