title: Heterotopic Ossification in Cervical Disk Surgery Is Still a Problem. What Are the Key Factors for a Solution?
abstract: BACKGROUND
  The aim of our study was to determine the presence of heterotopic ossifications (HO) in a series of patients with cervical disk arthroplasty treated with different type of prosthesis, as well as to analyze the most suitable systems for diagnosis.
  
  
  METHODS
  A retrospective study of patients with cervical disk disease treated with cervical arthroplasty between May 2005 and December 2009, was performed. Patients were divided into 3 groups, depending on the prosthesis implanted: (Group A: Baguera prosthesis, Group B: ProDisc prosthesis, and Group C: PCM prosthesis). The presence of heterotopic ossifications was evaluated with both, simple radiology and computed tomography.
  
  
  RESULTS
  As a summary of the results on motion preservation, computed tomography scans showed that 63% of the cervical arthroplasties in Group A presented good mobility at the first check point (December 2010), whereas cervical arthroplasties in Group B and Group C had 74% and 65% severe motion restrictions, respectively (Grade III or Grade IV, according to McAfee classification). The differences between groups were statistically significant when comparing Groups A and B, and Groups A and C (P < 0.05), but there were no differences between Groups B and C (P < 0.05). At the second check point (December 2014), the good mobility was just preserved in the 26% of the disk replacements (all in Group A).
  
  
  CONCLUSIONS
  Our results showed that, although cervical disks provide optimal mid-term results, the incidence of HO seems to increase with time. Long term studies, with a larger sample size should be conducted to evaluate the appearance of HO and cervical motion after total disk replacement.
authors: Spine Unit, Valladolid University Hospital, Valladolid, Spain. Electronic address: noriega1970@icloud.com.
authors: David Cesar
authors: DC
authors: Noriega
authors: Spine Unit, Valladolid University Hospital, Valladolid, Spain.
authors: Rubén Hernández
authors: RH
authors: Ramajo
authors: Department of Radiology, Valladolid University Hospital, Valladolid, Spain.
authors: Israel
authors: I
authors: Sánchez-Lite
authors: Department of Radiology, Valladolid University Hospital, Valladolid, Spain.
authors: Borja
authors: B
authors: Toribio
authors: Department of Neurosurgery, Trakya University, Edirne, Turkey.
authors: Emle
authors: E
authors: Delen
authors: Department of Neurosurgery, Bahçeşehir University, İstanbul, Turkey.
authors: Soner
authors: S
authors: Sahin
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000601:surgery*; D007405:Intervertebral Disc Displacement / Q000601:surgery*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging / Q000209:etiology*; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology*; D019106:Postoperative Hemorrhage / Q000000981:diagnostic imaging / Q000209:etiology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D059145:Total Disc Replacement / Q000009:adverse effects*
keywords: Anterior; Cervical; Cervical arthroplasty; Discectomy; Heterotopic ossification