title: Surgical treatment for thoracic spinal stenosis.
abstract: OBJECTIVE
  To describe the underlying causes, surgical results and prognostic factors in thoracic stenosis causing myelopathy.
  
  
  METHODS
  The underlying causes and surgical results were analyzed retrospectively in 28 cases of thoracic spinal stenosis which caused myelopathy. Degenerative spondylosis was the most common cause, and three cases were associated with systemic diseases. Decompressive laminectomy was performed in 24 cases, anterior decompression in five cases, and combined decompression in one case. Ossification of ligamentum flavum was found in 18 cases, facet hypertrophy in 13, ossification of posterior longitudinal ligament in six, and ventral spur in four. Postoperatively 16 patients improved and four patients worsened. Follow-up ranged from 2 months to 5 years and 8 months). Statistical analysis was performed using a chi(2) test to investigate the relationship between subjects. Multivariant analysis (general linear model) was used to determine the factors which influence surgical outcome.
  
  
  RESULTS
  There were neurological improvements in 16 patients, in whom Nurick grade changed from 3.3 preoperatively to 1.8 postoperatively. Eight patients showed no significant change in functional grade and four patients deteriorated after decompressive laminectomy. The group of which initial symptom duration was less than 2 years showed better results (P=0.006). The group with sufficient decompression and no additional proximal stenosis had better treatment outcome (P=0.005, P=0.002).
  
  
  CONCLUSIONS
  Chronic severe myelopathy caused by thoracic spinal stenosis can be reversible with appropriate decompression. Surgical outcome was dependent on initial symptom duration, sufficient decompression and presence of additional proximal stenosis.
  
  
  BACKGROUND
  This study was supported by a grant No. 02-1997-071-0 from the Seoul National University Hospital Research Fund.
authors.affiliation: Department of Neurosurgery, Neuroscience Research Institute, Seoul National University College of Medicine Clinical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: U K
authors.initials: UK
authors.lastname: Chang
authors.forename: W J
authors.initials: WJ
authors.lastname: Choe
authors.forename: C K
authors.initials: CK
authors.lastname: Chung
authors.forename: H J
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D017887:Ossification of Posterior Longitudinal Ligament / Q000175:diagnosis; D011379:Prognosis; D012189:Retrospective Studies; D013130:Spinal Stenosis / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D013904:Thoracic Vertebrae; D016896:Treatment Outcome