title: Surgical results and related factors for ossification of posterior longitudinal ligament of the thoracic spine: a multi-institutional retrospective study.
abstract: METHODS
  Retrospective multi-institutional study
  
  
  OBJECTIVE
  To describe the surgical outcomes in patients with ossification of the posterior longitudinal ligament in the thoracic spine (T-OPLL) and to clarify factors related to the surgical outcomes.
  
  
  BACKGROUND
  Detailed analyses of surgical outcomes of T-OPLL have been difficult because of the rarity of this disease.
  
  
  METHODS
  The subjects were 154 patients with T-OPLL who were surgically treated at 34 institutions between 1998 and 2002. The surgical procedures were laminectomy in 36, laminoplasty in 51, anterior decompression via anterior approach in 25 and via posterior approach in 29, combined anterior and posterior fusion in 8, and sternum splitting approach in 5 patients. Instrumentation was conducted in 52 patients. Assessments were made on (1) The Japanese Orthopedic Association (JOA) scores (full score, 11 points), its recovery rates, (2) factors related to surgical results, and (3) complications and their consequences.
  
  
  RESULTS
  (1) The mean JOA score before surgery was 4.6 +/- 2.0 and, 7.1 +/- 2.5 after surgery. The mean recovery rate was 36.8% +/- 47.4%. (2) The recovery rate was 50% or higher in 72 patients (46.8%). Factors significantly related to this were location of the maximum ossification (T1-T4) (odds ratio, 2.43-4.17) and the use of instrumentation (odds ratio, 3.37). (3) The frequent complications were deterioration of myelopathy immediately after surgery in 18 (11.7%) and dural injury in 34 (22.1%) patients.
  
  
  CONCLUSIONS
  The factors significantly associated with favorable surgical results were maximum ossification located at the upper thoracic spine and use of instrumentation. T-OPLL at the nonkyphotic upper thoracic spine can be treated by laminoplasty that is relatively a safe surgical procedure for neural elements. The use of instrumentation allows correction of kyphosis or prevention of progression of kyphosis, thereby, enhancing and maintaining decompression effect, and its use should be considered with posterior decompression.
authors.affiliation: Department of Musculoskeletal Reconstruction and Regeneration Surgery, Keio University, Department of Orthopedic Surgery, Tokyo, Japan. morio@sc.itc.keio.ac.jp
authors.forename: Morio
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Chiba
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.forename: Katsushi
authors.initials: K
authors.lastname: Takeshita
authors.forename: Atsushi
authors.initials: A
authors.lastname: Seichi
authors.forename: Kozo
authors.initials: K
authors.lastname: Nakamura
authors.forename: Jun
authors.initials: J
authors.lastname: Arimizu
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Fujibayashi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Hirabayashi
authors.forename: Toru
authors.initials: T
authors.lastname: Hirano
authors.forename: Motoki
authors.initials: M
authors.lastname: Iwasaki
authors.forename: Kouji
authors.initials: K
authors.lastname: Kaneoka
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Kawaguchi
authors.forename: Kosei
authors.initials: K
authors.lastname: Ijiri
authors.forename: Takeshi
authors.initials: T
authors.lastname: Maeda
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Matsuyama
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Mikami
authors.forename: Hideki
authors.initials: H
authors.lastname: Murakami
authors.forename: Hideki
authors.initials: H
authors.lastname: Nagashima
authors.forename: Kensei
authors.initials: K
authors.lastname: Nagata
authors.forename: Shinnosuke
authors.initials: S
authors.lastname: Nakahara
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nohara
authors.forename: Shiro
authors.initials: S
authors.lastname: Oka
authors.forename: Keizo
authors.initials: K
authors.lastname: Sakamoto
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Saruhashi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Sasao
authors.forename: Katsuji
authors.initials: K
authors.lastname: Shimizu
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Taguchi
authors.forename: Makoto
authors.initials: M
authors.lastname: Takahashi
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Tani
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Tokuhashi
authors.forename: Kenzo
authors.initials: K
authors.lastname: Uchida
authors.forename: Kengo
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Toru
authors.initials: T
authors.lastname: Yokoyama
authors.forename: Munehito
authors.initials: M
authors.lastname: Yoshida
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nishiwaki
mesh_terms: D000328:Adult; D000368:Aged; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D007564:Japan; D007796:Laminectomy; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects / Q000295:instrumentation; D017887:Ossification of Posterior Longitudinal Ligament / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D020127:Recovery of Function; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013123:Spinal Fusion; D013249:Sternum / Q000601:surgery; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome