title: Higher risk of adjacent segment degeneration after floating fusions: long-term outcome after low lumbar spine fusions.
abstract: METHODS
  We report the long-term outcome after mono-segmental and bisegmental fusions at the lumbar L4-S1 region of the spine.
  
  
  OBJECTIVE
  Long-term clinical and radiologic outcome measures were used to determine a lumbar fusion's contribution to degenerative changes in adjacent motion segments (ASD).
  
  
  BACKGROUND
  The role of low lumbar spinal fusions and their long-term contribution to accelerated degenerative changes in the adjacent motion segments continues to be a subject of controversy.
  
  
  METHODS
  We followed-up 102 patients with an average age of 54 (22 to 78) years and a follow-up time of 14 (3 to 22) years.
  
  
  RESULTS
  Overall results in patients were good, the Oswestry-Disability Index (ODI) showed an average of 26% (0% to 70%) at follow-up, the Visual Analog Scale rose from 2.7 (postoperative) and 2.9 (12 wk follow-up) to 3.6 (latest follow-up) points, respectively. Patient satisfaction with their health-related situation at follow-up was 69% (15% to 100%). Patients who underwent fusions of the segment L5/S1 showed a significant (P<0.05) lower risk for ASD than patients with fusions L4/5 (20% vs. 46%). Compared with L4/5 fusions, bisegmental L4-S1 fusions showed a similar trend (P=0.06) with a lower risk for ASD (24%). Objective and subjective clinical results showed no differences between these groups. Patients suffering from ASD showed significant (P<0.05) reduced sacral inclination and lumbar lordosis angles and also significant (P<0.05) higher ODI values compared with non-ASD patients.
  
  
  CONCLUSIONS
  We conclude that floating fusions of single low lumbar segments are more likely to result in ASD and are negatively influenced by sagittal plane abnormalities.
authors.affiliation: Department of Orthopaedic Surgery, Center for Musculoskeletal Surgery, Charité-University Medicine Berlin, Germany. alexander.disch@charite.de
authors.forename: Alexander Carl
authors.initials: AC
authors.lastname: Disch
authors.forename: Werner
authors.initials: W
authors.lastname: Schmoelz
authors.forename: Georg
authors.initials: G
authors.lastname: Matziolis
authors.forename: Sascha V
authors.initials: SV
authors.lastname: Schneider
authors.forename: Christian
authors.initials: C
authors.lastname: Knop
authors.forename: Michael
authors.initials: M
authors.lastname: Putzier
mesh_terms: D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000453:epidemiology / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology*; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D012447:Sacrum / Q000473:pathology / Q000601:surgery; D013123:Spinal Fusion / Q000009:adverse effects* / Q000706:statistics & numerical data; D013168:Spondylolisthesis / Q000453:epidemiology / Q000601:surgery*; D016896:Treatment Outcome