title: Variations of cervical lordosis and head alignment after pedicle subtraction osteotomy surgery for sagittal imbalance.
abstract: BACKGROUND
  The variations of the cervical lordosis after correction of sagittal imbalance have been poorly studied. The aim of our study is to verify whether the cervical lordosis changes after surgery for sagittal imbalance.
  
  
  METHODS
  Thirty-nine patients were included in the study. Cervical, thoracic and lumbar spine, pelvic and lower-limb sagittal parameters were recorded. The cranial alignment was measured by the newly described Cranial Slope.
  
  
  RESULTS
  The global cervical kyphosis (preop -43°, postop -31.5°) and the upper (preop -24.1°, postop -20.2°) and lower cervical kyphosis (preop -18.1°, postop -9.2°) were significantly reduced after surgical realignment of the trunk. A positive linear correlation was observed between the changes in T1 slope and the lower cervical lordosis, and between T1 slope and the global cervical alignment.
  
  
  CONCLUSIONS
  The cervical lordosis is reduced by surgical correction of malalignment of the trunk, suggesting an adaptive role to maintain the head's neutral position.
authors.affiliation: 2nd Spine Surgery Division, IRCCS Istituto Ortopedico Galeazzi, Via R. Galeazzi, 4, 20161, Milan, Italy, dott.cecchinato@gmail.com.
authors.forename: R
authors.initials: R
authors.lastname: Cecchinato
authors.forename: F
authors.initials: F
authors.lastname: Langella
authors.forename: R
authors.initials: R
authors.lastname: Bassani
authors.forename: V
authors.initials: V
authors.lastname: Sansone
authors.forename: C
authors.initials: C
authors.lastname: Lamartina
authors.forename: P
authors.initials: P
authors.lastname: Berjano
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D005260:Female; D006257:Head / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007738:Kyphosis / Q000000981:diagnostic imaging / Q000601:surgery; D008141:Lordosis / Q000000981:diagnostic imaging / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods*; D010388:Pelvis / Q000601:surgery; D011184:Postoperative Period; D011859:Radiography; D012189:Retrospective Studies; D013121:Spinal Curvatures / Q000000981:diagnostic imaging / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery