The outcomes of scoliosis surgery in patients with syringomyelia

Study Design. A retrospective review of a consecutive case series. Objective. To describe patient demographics, syrinx morphology, and deformity characteristics, as well as postsurgical correction, progression, and complications. Summary of Background Data. Conflicting data are available on the natural and postsurgical history of patients with spinal deformity associated with syringomyelia. This is the largest series in the literature on the surgical outcomes of these patients. Methods. All patients treated for spinal deformity at our institution with an associated syrinx were reviewed. Demographics, deformity morphology, treatment methods, and postoperative outcomes were measured and recorded. Results. Thirteen patients met inclusion criteria. All were Lenke thoracic modifier normal or positive. Ten patients underwent neurosurgical decompression. All curves either progressed or remained unchanged following neurosurgical treatment. The average thoracic kyphosis measured 46 degrees (29 degrees-69 degrees). Thoracic kyphosis was significantly increased compared with a population of adolescent idiopathic patients ( P = 0.00002). The average curve before scoliosis surgery was 71 degrees (31 degrees-119 degrees) in the coronal plane and 46 degrees (29 degrees-68 degrees) in the sagittal plane. The average correction from the initial scoliosis surgery was 48% (6%-83%). All patients had spinal cord monitoring or wake-up tests during surgery. There were no instances of spinal cord injury from surgery. Three patients progressed significantly following anterior fusion, 2 of whom required further corrective surgery. Following arthrodesis, 4 patients progressed > 10 degrees during follow-up. Conclusion. The lack of thoracic hypokyphosis seen in idiopathic-like curves is a strong indicator of a possible underlying syrinx. Neurosurgical treatment of the syrinx did not improve the scoliosis. Caution should be exercised when choosing fusion levels, and arthrodesis should be planned with the underlying pathology in mind. Scoliosis surgery has proven to be safe in patients with treated syrinx when spinal cord monitoring or wake-up tests are used.