Criteria for selective fusion in idiopathic scoliosis using Cotrel-Dubousset instrumentation.

Spinal decompensation after Cotrel-Dubousset (C-D) instrumentation in the King type II curve pattern has become a recognized complication secondary to progression of the unfused lumbar curve. Twenty-three patients with type II curves who underwent selective thoracic fusion according to the guidelines established by King et al. were reviewed. Mean follow-up was 19.5 months. Lumbar curves greater than 45 degrees associated with a low flexibility index were significantly more likely to develop postoperative progression of the uninstrumented lumbar curve with resultant spinal decompensation, suggesting that in these curves the King criteria for selective thoracic fusion may not be appropriate.