title: Influence of the Number of Cervical Fusion Levels on Cervical Spine Motion and Health-Related Quality of Life.
abstract: METHODS
  A retrospective study.
  
  
  OBJECTIVE
  To analyze the influence of the number of cervical fusion levels on total cervical motion and health-related quality of life (HRQoL) in patients with solid anterior cervical fusions (ACFs).
  
  
  BACKGROUND
  Few studies have analyzed the degree to which cervical range of motion (ROM) and HRQoL are affected by the number of cervical fusion segments.
  
  
  METHODS
  We analyzed a cohort of patients who underwent ACF for degenerative disc disease. To assess the clinical outcomes and HRQoL, preoperative, 1- and 2-year postoperative neck and arm pain, visual-analogue scale, neck disability index, and short form-36 were analyzed. Radiographically, C2-7 and C0-2 ROM, C2-7 sagittal vertical axis (SVA), and Kellgren grade of radiographic adjacent segment pathology (RASP) were evaluated.
  
  
  RESULTS
  A total of 105 patients (M:F = 46:59, mean age of 51.4 yr) were enrolled. There were 36 patients who underwent single-level ACF (group 1), 41 patients who had a double level ACF (group 2), and 28 patients who underwent ACF involving 3 or more levels (group 3). There was no decrease in C2-7 motion in group 1, a mean 7-degree decrease in group 2, a mean 18-degree decrease in those who underwent a 3-level ACF, and a mean 22-degree decrease after 4-level ACF. The grade of RASP was not influenced by the number of fusion levels. All HRQoL parameters showed no significant correlation between number of fusion levels, cervical ROM, and SVA.
  
  
  CONCLUSIONS
  Single-level ACF showed no decrease in total cervical motion; multilevel ACF decreased cervical motion by a mean of 7.8 degrees per segment of fusion. Progression of RASP showed no correlation with the number of fusion levels. HRQoLs were not influenced by the number of fusion levels, cervical ROM, or SVA after solid ACF.
  
  
  METHODS
  3.
authors.affiliation: *Department of Orthopedic Surgery, Kyung Hee University Hospital at Gangdong, Seoul, Korea †Soonchunhyang University Hospital, Seoul, Korea ‡Meijo Hospital, Nagoya, Japan §Columbia University Medical Center, New York, New York.
authors.forename: Sang-Hun
authors.initials: SH
authors.lastname: Lee
authors.forename: Jae Chul
authors.initials: JC
authors.lastname: Lee
authors.forename: Ryoji
authors.initials: R
authors.lastname: Tauchi
authors.forename: K
authors.initials: K
authors.lastname: Daniel Riew
mesh_terms: D002574:Cervical Vertebrae / Q000502:physiology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D016059:Range of Motion, Articular / Q000502:physiology; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000009:adverse effects / Q000379:methods* / Q000706:statistics & numerical data*