Staged Anterior Release and Posterior Instrumentation in Correction of Severe Rigid Scoliosis (Cobb Angle >100 Degrees)

Abstract

PurposeSevere rigid curves present a big challenge to the treating spine surgeon. We evaluated the outcome of staged anterior release and posterior instrumentation for rigid scoliosis. MethodsTwenty-one patients with an average age of 14.4 years (range 11–17) having a rounded severe rigid scoliosis (Cobb angle >100 degrees) underwent surgical correction. Six patients had congenital scoliosis, 13 idiopathic scoliosis, and 2 syndromic. All patients underwent anterior release in Stage I with one or more Ponte osteotomies and in Stage II with all pedicle screw instrumentation, and 13 of the patients underwent an asymmetric pedicle subtraction osteotomy at the apex. Patients were assessed for deformity correction, operative time, blood loss, and any complications. ResultsThe preoperative Cobb angle of 116.6 degrees (range 101–124 degrees) improved to 74.0 degrees (range 54–86 degrees) after anterior release: 29.4% correction and the final postoperation Cobb angle after posterior instrumentation was 26.5 degrees (range 22–32 degrees), with final 76% correction. The average blood loss in anterior release was 585.95 mL (range 400–980 mL; % estimated blood volume = 19.5%), whereas the mean operative time was 223 minutes (165–315 minutes). One patient had prolonged chest drain and two, basal atelectasis following anterior release. The mean operative time for the posterior procedure was 340 minutes (range 280–420 minutes) and average blood loss was 2,066 mL (range 1,200–3,200 mL). The mean apical axial rotation of 56 degrees (range 26–79 degrees) improved to 28 degrees (range 9–42 degrees) (p < .05). There was loss of motor evoked potential signal in one and hook pullout, superficial infection, and local skin necrosis one case each. ConclusionThe staged approach to the management of severe, rigid scoliosis helps get an excellent correction. Anterior release loosens up the rigid apex and provides with nearly 30% correction so that the extent of the osteotomies in the second stage from the back is substantially reduced, allowing for a final good correction.