Taking the shoulders and pelvis into account in the preoperative classification of idiopathic scoliosis in adolescents and young adults (a constructive critique of King's and Lenke's systems of classification).

INTRODUCTION: The surgical strategies to treat idiopathic scoliosis on adolescents and young adults need a basic reliable classification. King's and Lenke's classification are inappropriate because they fail to take shoulders and pelvis into account.
METHODS: We propose the answer for the following three questions: 1. Why are we challenging King's and Lenke's systems of classification? 2. How many frontal and possibly sagittal curves do we need to be able to develop a strategy which is applicable to almost all cases? 3. How should scoliotic curves be classified?
RESULTS: In double thoracic and lumbar (thoracic predominant) scoliosis, the concepts of "pelvis included" and "pelvis excluded" are not simply based on a semantic distinction, but correspond to different physiopathological entities and require different surgical strategies. In double thoracic curves the concepts of "real double thoracic" and "potential double thoracic" curves are keys to obtain post operative shoulder balance. In lumbar scoliosis the concepts of "real lumbar" and "lumbosacral" curves are necessary to compare results of posterior or anterior approach in surgical strategies. The system proposed in this work involves ten basic curves.
CONCLUSION: The surgical strategies used to treat idiopathic scoliosis in adolescents and young adults depend on the school of thought as to whether the anterior or posterior approach is preferable and the extent of the vertebral instrumentation. A consensus system of classification of scoliotic curves is required to compare the results obtained using various methods. This has been done in the improved version of King's system proposed here and should provide an efficient tool for use in comparative studies on surgical methods.