Allograft bone use during instrumentation and fusion in the treatment of adolescent idiopathic scoliosis

Study Design. In a retrospective study, 25 patients undergoing posterior spine fusion with allograft bone and Cotrel-Dubousset instrumentation were assessed regarding the efficacy of allograft bone use. Objectives. To determine if allograft bone use had deleterious effects regarding fusion rates and maintenance of deformity correction. Summary of Background Data. Previous studies using allograft bone in adult lumbar spine fusion models have consistently shown poor fusion rates. Studies in the pediatric population have been more favorable but in idiopathic cases have used cast or brace immobilization with Harrington instrumentation. Methods. Twenty-five skeletally immature patients with an average age of 14 +/- 4 years and an average follow-up of 4 +/- 2 years (minimum of 3 years) were evaluated with anteroposterior, lateral, and oblique radiographs to assess the fusion mass. Results, Preoperative curves averaged 55.5 degrees and immediate correction averaged 58% with an average postoperative curve of 23.2 degrees. Loss of correction at final follow-up was 3.7 degrees. No pseudarthroses were identified clinically or radiographically. Conclusions. Allograft bone use in the pediatric patient with idiopathic scoliosis undergoing rigid segmental instrumentation dependably results in fusion with good maintenance of correction.