title: Evolution of syrinx in patients undergoing posterior correction for scoliosis associated with syringomyelia.
abstract: OBJECTIVE
  While correction surgery for syringomyelia-associated scoliosis frequently results in an elongation of the spine and may potentially influence the natural history of syringomyelia, a paucity of data exists regarding the syrinx behavior in the postoperative course. This study aimed to investigate the natural evolution of syrinx in patients undergoing one-stage posterior instrumented spinal fusion for treatment of scoliosis associated with idiopathic syringomyelia (IS).
  
  
  METHODS
  Twenty-two patients with IS-associated scoliosis treated with one-stage posterior correction and fusion were evaluated at a minimum of 12-month clinical and MRI follow-up (mean 29.6 months; range 12-57 months). All syringes were located within the cervical or cervicothoracic region. Standing anteroposterior radiographs were examined for primary curve magnitude and postoperative correction. On preoperative and follow-up T2-weighted MR images, location, configuration and size of the syrinx cavity were systematically assessed, and significant syrinx resolution was defined as any more than 20% decrease in length or maximal syrinx/cord ratio.
  
  
  RESULTS
  Postoperative percent correction of the primary curve averaged 64.0 ± 15.7% and was well maintained (58.5 ± 11.5%) at latest evaluation. Regarding syrinx size, although paired t test revealed no statistically significant difference between pre- and postoperative maximal syrinx/cord ratios (0.44 versus 0.41; P > 0.05), 10 of 22 (45.5%) patients were found to meet the criteria for significant syrinx resolution. Additionally, 11 (50.0%) patients had syrinx stabilization, whereas syrinx deterioration was observed only in 1 case (4.5%) at final follow-up. Using Spearman correlation test, improvement rate of the maximal syrinx/cord ratio was found to be strongly related to the coronal percent correction of the primary curve (r = -0.547, P = 0.008). There were no neurologic or other major complications related to the surgery.
  
  
  CONCLUSIONS
  For treatment of scoliosis associated with IS in the setting of minimal neurological deficits, one-stage spinal fusion with a lengthening of the vertebral column provides an effective coronal and sagittal correction without neurologic complications. Following surgery, the vast majority (95.5%) of syringes shrank or remained stable, indicating that deformity correction did not exert a deleterious effect on the natural evolution of syringomyelia.
authors.affiliation: Department of Spine Surgery, Drum Tower Hospital of Nanjing University Medical School, Zhongshan Road No. 321, Nanjing, 210008, China.
authors.forename: Shifu
authors.initials: S
authors.lastname: Sha
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Feng
authors.initials: F
authors.lastname: Zhu
authors.forename: Zezhang
authors.initials: Z
authors.lastname: Zhu
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011184:Postoperative Period; D011187:Posture; D012189:Retrospective Studies; D012600:Scoliosis / Q000209:etiology / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects* / Q000379:methods; D013131:Spine / Q000601:surgery; D013595:Syringomyelia / Q000150:complications / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult