title: Influence of number of operated levels and postoperative time on active range of motion following anterior cervical decompression and fusion procedures.
abstract: METHODS
  A cohort study analyzing the cervical range of motion of subjects with anterior cervical decompression and fusion operation (ACDF).
  
  
  OBJECTIVE
  The purpose of this study was to compare the cervical range of motion of subjects who underwent an ACDF operation to age-matched healthy nonoperative subjects. Subjects were divided according to the number of operated levels, postoperative time point, and level of disability.
  
  
  BACKGROUND
  ACDF is an operative treatment aimed at expansion of the spinal canal and relief of cord compression. In addition to alleviating pain, 2 common tools are used to measure postoperative success; cervical range of motion kinematic analysis and subjective evaluation questionnaires (Neck Disability Index [NDI]).
  
  
  METHODS
  This study involved 25 preoperative and 110 postoperative ACDF subjects as well as 18 control volunteers with no prior history of neck complaints. ACDF subjects were divided according to the number of operated levels; 1-, 2-, 3-, and 4-levels as well as time of their clinical visit; preoperative, early, and late postoperative. Before kinematic testing, the subjects were asked to complete the NDI survey. A virtual reality assisted electromagnetic tracking was used to measure an active voluntary motion of the head relative to the torso. The subjects' maximum range of motion was calculated and compared as they executed 3 to 5 consecutive cycles of the primary motions, flexion/extension, axial rotation, and lateral bending. An analysis of variance statistical test (P < 0.01) was used to determine significant differences between study groups. RESULTS.: Subject's range of motion decreased relative to control as the number of operated levels increased. Moreover, 1- and 2-level subjects increased their range motion relative to preoperative. Finally, there was a decrease in range of motion as the subject's level of disability increased as measured by an NDI score but all subjects reported a lower score relative to preoperative time point.
  
  
  CONCLUSIONS
  The active range of motion of subjects who underwent an ACDF surgery increased postoperative and was dependent on the number of operated levels. In addition, there was an improvement in the disability level after the surgery as measured by the NDI score.
authors.affiliation: Department of Orthopaedic Surgery, Ferguson Laboratory for Spine Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. bellkm@upmc.edu
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Bell
authors.forename: Bernard P
authors.initials: BP
authors.lastname: Bechara
authors.forename: Robert A
authors.initials: RA
authors.lastname: Hartman
authors.forename: Charise
authors.initials: C
authors.lastname: Shively
authors.forename: Eric C
authors.initials: EC
authors.lastname: Frazier
authors.forename: Joon Y
authors.initials: JY
authors.lastname: Lee
authors.forename: James D
authors.initials: JD
authors.lastname: Kang
authors.forename: William F
authors.initials: WF
authors.lastname: Donaldson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000503:physiopathology* / Q000601:surgery*; D015331:Cohort Studies; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D016059:Range of Motion, Articular; D013123:Spinal Fusion / Q000379:methods*; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult