Does Surgical Correction of Right Thoracic Scoliosis in Syringomyelia Produce Outcomes Similar to Those in Adolescent Idiopathic Scoliosis?

Background: Practice guidelines for deformity correction in patients with syringomyelia-associated scoliosis (SMS) remain ill defined. Although surgeons experienced in treating adolescent idiopathic scoliosis (AIS) are commonly called on to treat SMS, no study has directly compared the results of surgical treatment between patients with SMS and those with AIS. The present study was performed to compare the radiographic and clinical outcomes of posterior spinal fusion between patients with right-thoracic SMS and those with right-thoracic AIS. Methods: Sixty-nine adolescents with SMS were matched with patients with AIS for sex, age, and curve magnitude. Patients were evaluated before surgery, immediately after surgery, and at the latest follow-up examination for changes in curve correction, global coronal balance, and scores on the Scoliosis Research Society (SRS)-22 questionnaire. Results: The preoperative primary curve magnitude was similar between the two groups, but a trend toward less flexibility was observed in the SMS group. The amount of correction of the thoracic Cobb angles obtained surgically (68% compared with 71%) and the ratio of percent correction to flexibility (1.80 compared with 1.76) were similar in the SMS and AIS groups. At the latest evaluation, eight patients with SMS and five with AIS had lost >10 degrees of thoracic spine correction (p = 0.382). The postoperative coronal decompensation averaged 13% and 6%, respectively, in the SMS and AIS groups (p = 0.243). No intergroup differences were noted with respect to the sagittal vertical axis or proximal junctional change, with preservation of global sagittal balance in both groups during follow- up. There were no neurologic or other major complications related to surgery in either group. Conclusions: Despite the differences in preoperative status, adolescents with idiopathic right thoracic scoliosis and those with syringomyelia-associated right thoracic scoliosis had comparable clinical and radiographic outcomes of pedicle-screw-based posterior spinal fusion, without neurologic complications.