title: [Segmental cut-off bridge and local floating technology for the treatment of ossification of ligamentum flavum in thoracic spine].
abstract: OBJECTIVE
  To explore the efficacy and safety of segmental cut-off bridge and local floating technology for the treatment of ossification of ligamentum flavum (OLF) in thoracic spine.
  
  
  METHODS
  Retrospective study was performed in 98 patients with thoracic OLF who under went operation. There was 56 males and 42 females with an average age of 45.8 (35-73) years. The average duration of onset was 17 (3-51) months. The main clinical symptoms were numbness and paraesthesia (n = 90), lower limb weakness and walking trouble (n = 46), positive pyramidal tract signs (n = 33) and sphincter function obstacle (n = 9). OLF was screened and diagnosed by radiology, magnetic resonance imaging (MRI), computed tomography (CT) or CT myelography (CTM). A total of 142 OLF nidus were spotted. The lesions involved single segment (n = 32), double segments (n = 56), three segments (n = 6) and ≥ four segments (n = 4). And the locations were at upper thoracic segment (T1-4) (n = 34), middle thoracic segment (T5-8) (n = 23) and lower thoracic segment (T9-12) (n = 42). The OLF nidus were removed by local floating technology oft windowing at cephalic and caudal ends and a cut-off bridge at both sides of involved segments. Pre- and post-operative Japanese Orthopedic Association (JOA) scores and Epstein grades were recorded to evaluate the outcomes.
  
  
  RESULTS
  The mean loss volume of blood was 320 ml and operative duration 155 min. All cases recovered independent activities. The mean follow-up period was 28 (13-48) months. The mean preoperative JOA score was 4.3 (1-8) points and the mean postoperative JOA score 9.7 (5-11) points. The recovery rate was 78.8%. According to Epstein grade, the excellent and good rate was 86.7%.
  
  
  CONCLUSIONS
  As a common cause of thoracic spinal cord compression, OLF should be operated as early as possible. Based upon clinical and imaging findings, the application of segmental cut-off bridge and local floating technology is both safe and efficacious in the treatment of OLF in thoracic spine.
authors.affiliation: Department of Spinal Surgery, First Affiliated Hospital, Xinjiang Medical College, Urumqi 830054, China.
authors.forename: Wei-dong
authors.initials: WD
authors.lastname: Liang
authors.affiliation: Department of Spinal Surgery, First Affiliated Hospital, Xinjiang Medical College, Urumqi 830054, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Spinal Surgery, First Affiliated Hospital, Xinjiang Medical College, Urumqi 830054, China. Email: wbsheng@vip.sina.com.
authors.forename: Wei-bin
authors.initials: WB
authors.lastname: Sheng
mesh_terms: D000328:Adult; D000368:Aged; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D006801:Humans; D017843:Ligamentum Flavum / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000601:surgery*; D012189:Retrospective Studies; D013904:Thoracic Vertebrae; D016896:Treatment Outcome