title: Multilevel arthroplasty for cervical spondylosis: more heterotopic ossification at 3 years of follow-up.
abstract: METHODS
  Retrospective cohort study.
  
  
  OBJECTIVE
  To investigate the differences between single- and multilevel degenerative disc diseases (DDDs) treated with cervical arthroplasty.
  
  
  BACKGROUND
  The US Food and Drug Administration clinical trials compared arthroplasty with anterior cervical discectomy and fusion for single-level DDD. However, cervical arthroplasty for multilevel DDD is rarely addressed in the literature.
  
  
  METHODS
  A total of 102 consecutive patients who underwent Bryan arthroplasty were divided into either a single- or multilevel group. Clinical outcomes were measured by the visual analogue scale (VAS) of neck and arm, and by the neck disability index with a minimum follow-up of 25 months. Every patient had radiographical evaluations, and computed tomography.
  
  
  RESULTS
  Eighty-six patients (84.3%) completed the follow-up with a mean time of 38.3 ± 8.7 months. Postoperatively, there were significant improvements in clinical outcomes (i.e., VAS neck, VAS arm, and neck disability index) at each time point of evaluation (i.e., 3-, 6-, 12-, and 24 mo postoperation). The sex composition and clinical outcome improvements between the single- and multilevel groups were not significantly different. The multilevel group was older (51.3 ± 8.6 vs. 46.3 ± 11.2 yr; P = 0.02), had more intraoperative blood loss (218.0 ± 182.4 vs. 102.8 ± 79.2 mL; P = 0.001), and demonstrated a higher rate of heterotopic ossification (HO) than the single-level group (66.0% vs. 25.0%; P < 0.001). The majority (97.7%) of the artificial discs in this series remained mobile despite HO.
  
  
  CONCLUSIONS
  Clinical outcomes of cervical arthroplasty in multilevel spondylosis are similar to single-level outcomes. However, the significantly higher rate of HO found in multilevel arthroplasty and its long-term effect warrant further investigation.
authors: Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.
authors: Jau-Ching
authors: JC
authors: Wu
authors: Wen-Cheng
authors: WC
authors: Huang
authors: Tzu-Yun
authors: TY
authors: Tsai
authors: Li-Yu
authors: LY
authors: Fay
authors: Chin-Chu
authors: CC
authors: Ko
authors: Tsung-Hsi
authors: TH
authors: Tu
authors: Ching-Lan
authors: CL
authors: Wu
authors: Henrich
authors: H
authors: Cheng
mesh_terms: D000328:Adult; D000368:Aged; D001178:Arthroplasty / Q000379:methods*; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D017586:Diskectomy / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging; D010147:Pain Measurement; D012189:Retrospective Studies; D055009:Spondylosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult