Research

Introduction: Current classifications of surgical cases of adolescent idiopathic scoliosis (AIS) do not cover all curve patterns. The purpose of this study was to develop a comprehensive classification covering all surgical cases of AIS.

Methods: A retrospective radiographic review was carried out on all surgical cases of AIS operated on prior to 12-31-98. Cases were eliminated if there were an incomplete set of radiographs or if the follow-up was less than 2 years. Pre-operative standing, supine side bending and 2-year and latest follow-up films were reviewed.

Results: A total of 1049 cases were categorized. Seventy-nine percent of the cases fell into one of the five groups of the original King classification. The remaining 21% were categorized into six groups. In addition, double thoracic curves were divided into three sub-classifications depending on the type of lower thoracic curve (a compensatory lumbar curve; all lumbar vertebrae on the central sacral gravity line and a decompensated thoracic curve). Overall, there were 13 categories, all based on both curve pattern and the curve(s) to be fused.

Conclusion: This new clinical classification covers all curve patterns of AIS and is designed to provide guidance in surgical decision-making.