Effect of posterior multilevel vertebral osteotomies on coronal and sagittal balance in fused scoliosis deformity caused by previous surgery: Preliminary results

STUDY DESIGN.: Prospective case series study. OBJECTIVE.: To study the effect of posterior multilevel vertebral osteotomy (posterior crack osteotomy) on coronal and sagittal balance in patients with the fusion mass over the spine caused by previous surgery. SUMMARY OF BACKGROUND DATA.: Few studies have investigated revisional scoliosis surgery with the fusion mass using osteotomy. METHODS.: Among patients who had a history of prior surgery for scoliosis correction and posterior fusion, those showing progression of the curve postoperatively due to nonunion, implant failure, or adding-on phenomenon were enrolled. All patients were treated using posterior crack osteotomy. For clinical evaluation, the pre- and postoperative Gross Motor Function Classification System score for walking status and the Berg balanced scale were used. For radiological evaluation, pre- and postoperative Cobb angle, and coronal and sagittal balance factors were used. RESULTS.: Ten patients (5 males and 5 females) were enrolled. The preoperative diagnosis was neuromuscular scoliosis (3 cases), syndromic scoliosis (1 case), congenital scoliosis (5 cases), and neurofibromatosis (1 case). Osteotomies were performed at 3.3 ± 1.3 levels on average. Pre- and postoperative Cobb angles were 70.8°± 30.0° and 28.1°± 20.0° (P = 0.002 (0.97)), respectively. In pre- and postoperative evaluation of coronal balance, the coronal balance, clavicle angle, and T1-tilt angle were 36.8 ± 27.1 mm and 10.4 ± 8.5 mm, 6.7°± 8.0° and 3.3°± 1.5°, and 7.8°± 19.0° and 4.7°± 2.1°, respectively (P = 0.002, 0.002, 0.002). In pre- and postoperative evaluation of sagittal balance, the spinal vertical axis, thoracic kyphosis, and lumbar alignments were 25.1 ± 37.8 mm and 14.1 ± 21.8 mm, 33.5°± 51.1° and 29.7°± 27.4°, and 45.7°± 34.8° and 48.9°± 23.1° (P = 0.002, 0.169, 0.169). The walking and functional statuses did not change (P = 0.317, 0.932). Although pulmonary and gastrointestinal complications were noted, the patients were discharged without complications. CONCLUSION.: Posterior crack osteotomy can be used effectively in revisional scoliosis surgery and the clinical and radiological results seem to be acceptable.Level of Evidence: 4.