title: Motion-preserving surgery can prevent early breakdown of adjacent segments: Comparison of posterior dynamic stabilization with spinal fusion.
abstract: METHODS
  A retrospective study.
  
  
  OBJECTIVE
  This study aims to determine the prevalence and nature of adjacent-segment deterioration after posterior ligamentoplasty, posterolateral lumbar fusion (PLF) versus posterior lumbar interbody fusion (PLIF).
  
  
  BACKGROUND
  Motion-preserving technologies including disc arthroplasty and ligamentoplasty were gaining interest to reduce the risk of adjacent-segment morbidity. However, few clinical studies have reported the prevalence of adjacent-segment disease in motion-preserving surgeries.
  
  
  METHODS
  Two-hundred and eighteen consecutive patients who had undergone single-level posterior L4-L5 pedicle-screw-instrumented fusion or ligamentoplasty were reviewed at minimum 2-year follow-up. They were 91 males and 127 females with mean age of 62 years. Follow-up period was averaged 41 months and follow-up rate was 97.3%. There were 78 cases of PLIF, 75 of PLF, and 65 of ligamentoplasty. Demographics were not statistically different among the 3 groups. Prevalence of adjacent-segment morbidity (radiculopathy associated with newly developed pathologies at neighboring levels) and required additional surgery were investigated.
  
  
  RESULTS
  Prevalence of adjacent-segment morbidity was 14.1% in PLIF, 13.3% in PLF, and 9.2% in ligamentoplasty; the time to represent symptom was averaged 25.2, 39.3, and 51.8 postoperative months, respectively. Additional surgeries for adjacent-segment pathologies were required for 7.6% in PLIF, 6.7% in PLF, and 1.5% in ligamentoplasty. Although all PLF cases needed only decompression surgeries, 66.7% of reoperations in the PLIF group required fusion owing to progression of adjacent-segment instability.
  
  
  CONCLUSIONS
  Prevalence of adjacent-segment disease and reoperation rate seemed to be lower in ligamentoplasty than fusion surgeries, but the difference was not significant. Ligamentoplasty circumvented adjacent-segment disease for longer period than fusion surgeries. Although the rates of additional surgeries in PLIF and PLF were comparable, PLIF developed adjacent-level instability and required fusion surgery more frequently than PLF.
authors.affiliation: Spine Center, Hakodate Central General Hospital, Hokkaido, Japan. mkanayama@aol.com
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kanayama
authors.forename: Daisuke
authors.initials: D
authors.lastname: Togawa
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Keiichi
authors.initials: K
authors.lastname: Shigenobu
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Oha
mesh_terms: D000368:Aged; D001863:Bone Screws / Q000009:adverse effects; D005260:Female; D006801:Humans; D007049:Iatrogenic Disease / Q000453:epidemiology / Q000517:prevention & control; D007403:Intervertebral Disc / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D007405:Intervertebral Disc Displacement / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D007593:Joint Instability / Q000453:epidemiology* / Q000473:pathology / Q000503:physiopathology; D008022:Ligaments / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery; D017116:Low Back Pain / Q000209:etiology / Q000473:pathology / Q000601:surgery; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology* / Q000473:pathology / Q000503:physiopathology; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology; D019651:Plastic Surgery Procedures / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D055502:Secondary Prevention; D013123:Spinal Fusion / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data; D013168:Spondylolisthesis / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome