Anterior/posterior spinal instrumentation versus posterior instrumentation alone for the treatment of adolescent idiopathic scoliotic curves more than 90°

STUDY DESIGN. A retrospective review of patients with adolescent idiopathic scoliosis (AIS), with curves more than 90°treated with either a combined anterior/posterior spinal fusion or a posterior spinal fusion alone. OBJECTIVES. To assess the results of spinal fusion for AIS curves >90°and determine whether the use of a posterior-only approach with an all-pedicle screw construct can decrease the need for anterior release surgery. SUMMARY OF BACKGROUND DATA. Treatment of AIS curves >90°often consists of anterior release and posterior fusion to improve coronal correction and fusion rate. However, the use of pedicle screws has allowed improved coronal curve correction rates even in large curves, which may decrease the need for anterior release surgery. METHODS. A total of 54 consecutive patients with AIS with curves >90°who underwent a spinal fusion procedure at 1 institution between 1987 and 2001, with either a combined anterior/posterior spinal fusion (hooks and screws) or a posterior spinal fusion alone with an all-pedicle screw construct, were included for analysis. All patients had a minimum 2-year follow-up (mean 6.0; range 2.0-14.5), and were analyzed radiographically as well as with pulmonary function tests. Statistical analyses were performed between groups using the Wilcoxon-Mann-Whitney tests. RESULTS. There were 20 patients treated with an anterior/posterior spinal fusion and 34 with a posterior spinal fusion alone. There were no statistically significant differences between the groups for gender, age, number of levels fused, preoperative coronal/sagittal Cobb measurements, coronal curve flexibility, or amount of postoperative coronal Cobb correction. There was less of a negative effect on pulmonary function in the group treated with posterior spinal fusion versus the group treated with a combined anterior/posterior spinal fusion (P < 0.005). There were no complications/reoperations in either group. CONCLUSION. In this patient population with often restrictive preoperative pulmonary function, a posterior-only approach with the use of an all-pedicle screw construct has the advantage of providing the same correction as an anterior/posterior spinal fusion, without the need for entering the thorax and more negatively impacting pulmonary function.