title: Correlation between cervical lordosis and adjacent segment pathology after anterior cervical spinal surgery.
abstract: OBJECTIVE
  To evaluate the incidence and risk factors for adjacent segment pathology (ASP) after anterior cervical spinal surgery.
  
  
  METHODS
  Fourteen patients (12 male, mean age 47.1 years) who underwent single-level cervical disk arthroplasty (CDA group) and 28 case-matched patients (24 male, mean age 53.6 years) who underwent single-level anterior cervical discectomy and fusion (ACDF group) were included. Presence of radiologic ASP (RASP) was based on observed changes in anterior osteophytes, disks, and calcification of the anterior longitudinal ligament on lateral radiographs.
  
  
  RESULTS
  The mean follow-up period was 43.4 months in the CDA group and 44.6 months in the ACDF group. At final follow-up, ASP was observed in 5 (35.7%) CDA patients and 16 (57.1%) ACDF patients (p = 0.272). The interval between surgery and ASP development was 33.8 months in the CDA group and 16.3 months in the ACDF group (p = 0.046). The ASP risk factor analysis indicated postoperative cervical angle at C3-7 being more lordotic in non-ASP patients in both groups. Restoration of lordosis occurred in the CDA group regardless of the presence of ASP, but heterotopic ossification development was associated with the presence of ASP in the CDA group. And the CDA group had significantly greater clinical improvements than those in the ACDF group when ASP was present.
  
  
  CONCLUSIONS
  In both CDA and ACDF patients, RASP developed, but CDA was associated with a delay in ASP development. A good clinical outcome was expected in CDA group, even when ASP developed. Restoration of cervical lordosis was an important factor in anterior cervical spine surgery.
authors.affiliation: Department of Neurosurgery, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Soo Eon
authors.initials: SE
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 173-82 Gumi-Ro, Bundang-Gu, Seongnam, Gyeonggi-Do, 463-707, Republic of Korea. taj@snu.ac.kr.
authors.forename: Tae-Ahn
authors.initials: TA
authors.lastname: Jahng
authors.affiliation: Department of Neurosurgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 173-82 Gumi-Ro, Bundang-Gu, Seongnam, Gyeonggi-Do, 463-707, Republic of Korea.
authors.forename: Hyun Jib
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002574:Cervical Vertebrae / Q000601:surgery*; D017586:Diskectomy / Q000009:adverse effects; D005260:Female; D006801:Humans; D015994:Incidence; D007403:Intervertebral Disc / Q000601:surgery; D055959:Intervertebral Disc Degeneration / Q000453:epidemiology* / Q000209:etiology; D008141:Lordosis / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011843:Radiculopathy / Q000601:surgery; D012307:Risk Factors; D013123:Spinal Fusion / Q000009:adverse effects; D059145:Total Disc Replacement / Q000009:adverse effects*; D016896:Treatment Outcome
keywords: Anterior cervical discectomy and fusion; Cervical disk arthroplasty; Heterotopic ossification; Lordosis; Range of motion