title: Surgery for thoracic myelopathy caused by ossification of the ligamentum flavum.
abstract: BACKGROUND
  Ossification of the ligamentum flavum overlying the lower thoracic spine frequently produces myelopathy. This study analyzed the postoperative outcomes after decompressive laminectomy for thoracic OLF.
  
  
  METHODS
  We retrospectively studied 13 patients (10 male, 3 female; mean age, 58 years; range, 39-69). The mean follow-up duration was 66 months (range, 21-107). All patients had undergone decompressive laminectomy and excision of the OLF. The clinical course was evaluated according to the Frankel grading system and JOA scores. The number of vertebral segments demonstrating OLF, the most frequent level of thoracic cord involvement, and spine lesions coexisting with OLF were determined by MR imaging.
  
  
  RESULTS
  By the Frankel system, 7 of 13 patients improved by one grade, whereas the others, classified as grade D, were unchanged after surgery. Using the JOA score, the functional improvement was excellent in 3 patients, good in 4, fair in 2, and unchanged in 4. The number of vertebral segments demonstrating OLF included 4 levels in 2 patients, 3 levels in 2 patients, 2 levels in 5 patients, and 1 level in 4 patients. Ossification of the ligamentum flavum occurred most frequently at the T10/T11 level. Tandem cervical and lumbar lesions were present in 6 patients.
  
  
  CONCLUSIONS
  Decompressive laminectomy for excision of OLF resulted in clinical improvement using the Frankel grading system in 7 of 13 patients. In myelopathy patients with OLF, preoperative MR imaging of the entire spine is necessary because other coexisting spinal lesions may be present.
authors.affiliation: Department of Orthopedic Surgery, Shinshu University School of Medicine, Nagano 390-8621, Japan. hirokihi@hsp.md.shinshu-u.ac.jp
authors.forename: Hiroki
authors.initials: H
authors.lastname: Hirabayashi
authors.forename: Sohei
authors.initials: S
authors.lastname: Ebara
authors.forename: Jun
authors.initials: J
authors.lastname: Takahashi
authors.forename: Katsumi
authors.initials: K
authors.lastname: Narasaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Takahara
authors.forename: Gyo
authors.initials: G
authors.lastname: Murakami
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kato
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007796:Laminectomy; D017843:Ligamentum Flavum; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D012189:Retrospective Studies; D013117:Spinal Cord Compression / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D013122:Spinal Diseases / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D013904:Thoracic Vertebrae; D016896:Treatment Outcome