title: Clinical significance of achieving a flexion limitation with a tension band system in grade 1 degenerative spondylolisthesis: a minimum 5-year follow-up.
abstract: METHODS
  Retrospective clinical study.
  
  
  OBJECTIVE
  To evaluate the effect of the limitation of flexion rotation clinically and radiologically after interspinous soft stabilization using a tension band system in grade 1 degenerative spondylolisthesis.
  
  
  BACKGROUND
  Although several studies have been published on the clinical effects of limiting rotatory motion using tension band systems, which mainly targets the limitation of flexion rather than that of extension, they were confined to the category of pedicle screw-based systems, revealing inconsistent long-term outcomes.
  
  
  METHODS
  Sixty-one patients with a mean age of 60.6 years (range, 28-76 yr) who underwent interspinous soft stabilization after decompression for grade 1 degenerative spondylolisthesis with stenosis between 2002 and 2004 were analyzed. At follow-up, the patients were divided into 2 groups on the basis of their achievement or failure to achieve flexion limitation. The clinical and radiological findings were analyzed. A multiple linear regression analysis was performed to determine the prognostic factors for surgical outcomes.
  
  
  RESULTS
  At a mean follow-up duration of 72.5 months (range, 61-82 mo), 51 patients were classified into the flexion-limited group and 10 into the flexion-unlimited group. Statistically significant improvements were noted only in the flexion-limited group in all clinical scores. In the flexion-unlimited group, there were significant deteriorations in flexion angle (P = 0.009), axial thickness of the ligamentum flavum (P = 0.013), and the foraminal cross-sectional area (P = 0.011), resulting in significant intergroup differences. The preoperative extension angle was identified as the most influential variable for the flexion limitation and the clinical outcomes.
  
  
  CONCLUSIONS
  The effects of the limitation of flexion rotation achieved through interspinous soft stabilization using a tension band system after decompression were related to the prevention of late recurrent stenosis and resultant radicular pain caused by flexion instability. The extension potential at the index level was recognized as a major prognostic factor that can predict the flexion limitation and the clinical results.
  
  
  METHODS
  4.
authors.affiliation: *Department of Neurosurgery, Wooridul Spine Hospital, Seoul, Korea †Department of Neurosurgery, Gangbuk Wooridul Spine Hospital, Seoul, Korea ‡Department of Neurosurgery, Daegu Wooridul Spine Hospital, Daegu, Korea; and §Wooridul Institute for Biomedical Science and Technology, Seoul, Korea.
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: Ho-Yeon
authors.initials: HY
authors.lastname: Lee
authors.forename: Oon Ki
authors.initials: OK
authors.lastname: Baek
authors.forename: Jun Seok
authors.initials: JS
authors.lastname: Bae
authors.forename: Seung-Hwa
authors.initials: SH
authors.lastname: Yoo
authors.forename: June-Ho
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000368:Aged; D001416:Back Pain / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects / Q000379:methods*; D011183:Postoperative Complications; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology; D012086:Reoperation; D012189:Retrospective Studies; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome