title: Segmental motion adjacent to anterior cervical arthrodesis: a prospective study.
abstract: METHODS
  Prospective, observational study.
  
  
  OBJECTIVE
  The present study describes in a prospective setting the kinematics changes occurring at segments adjacent to a one-level cervical arthrodesis.
  
  
  BACKGROUND
  The development of adjacent segment disease has been noticed by many clinicians. Whether symptoms develop due to fusion induced accelerated spondylosis or due to a natural development in a predisposed person is currently under debate. The motivation for introducing motion preservation procedures in the neck is primarily to protect the patients from developing symptomatic adjacent disc disease. To accept this rationale, it has to be demonstrated that a fusion creates an unfavorable biomechanical situation at adjacent levels.
  
  
  METHODS
  Forty-six patients underwent standard anterior cervical decompression and fusion using a cylindrical cage implant. Lateral radiographic views of the cervical spine in flexion and extension were obtained before surgery, and at 12 months of follow-up. Employing Distortion Compensated Roentgen Analysis, rotational and translational motion at adjacent levels was quantified prospectively.
  
  
  RESULTS
  Rotational and translational motion at adjacent cranial and caudal levels did not exhibit a significant change between the preoperative state and the state 12 months after the operation.
  
  
  CONCLUSIONS
  The assumption of an iatrogenically caused increased mobility by a one-level cervical fusion could not be confirmed 12 months after surgery.
authors.affiliation: National Centre of Spinal Disorders, St. Olav University Hospital, Trondheim, Norway. Frode.Kolstad@ntnu.no
authors.forename: Frode
authors.initials: F
authors.lastname: Kolstad
authors.forename: Øystein P
authors.initials: ØP
authors.lastname: Nygaard
authors.forename: Gunnar
authors.initials: G
authors.lastname: Leivseth
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology / Q000517:prevention & control; D010147:Pain Measurement; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000517:prevention & control; D011446:Prospective Studies; D011843:Radiculopathy / Q000150:complications / Q000601:surgery; D011859:Radiography; D016059:Range of Motion, Articular; D012399:Rotation; D013118:Spinal Cord Diseases / Q000150:complications / Q000601:surgery; D013123:Spinal Fusion / Q000009:adverse effects; D013128:Spinal Osteophytosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D013997:Time Factors; D016896:Treatment Outcome