Modification of Cotrel-Dubousset's original hook constructs for idiopathic scoliosis

We performed a retrospective review of 41 patients (ages 9-18 years) who underwent posterior spinal fusion with either Isola or Cotrel-Dubousset (CD) instrumentation to determine whether the presence of an apical hook on the thoracic convexity affected initial and long-term sagittal and coronal correction in adolescent idiopathic scoliosis surgery. A study group of 38 female and three male patients was evaluated (2-5 years of follow-up). Twenty-three patients (Group A) were treated with an up-going hook at the convex apex of the thoracic curve, and 18 patients (Group B) with similar curves were instrumented without an apical hook. Results showed that Group A's average preoperative coronal curve of 48 degrees decreased to 17 degrees , whereas Group B's preoperative average of 52 degrees decreased to 25 degrees . At follow-up, no statistical significance was noted in either coronal curve correction (p = 0.203) or sagittal kyphosis (p = 0.38) between Groups A and B. We conclude that omission of the up-going hook at the apex of the thoracic convexity can reduce postoperative discomfort in patients undergoing posterior spinal fusion, without sacrificing curve correction or balance.