title: Posterior Cervical Fusion Using Cervical Interfacet Spacers in Patients With Symptomatic Cervical Pseudarthrosis.
abstract: BACKGROUND
  Posterior cervical fusion with cervical interfacet spacer (CIS) is a novel allograft technology offering the potential to provide indirect neuroforaminal decompression while simultaneously enhancing fusion by placing the allograft in compression.
  
  
  OBJECTIVE
  To analyze the clinical and radiological outcomes after posterior cervical fusion with CIS in patients with symptomatic anterior cervical pseudarthroses.
  
  
  METHODS
  Medical records of patients who underwent posterior cervical fusion with CIS for symptomatic pseudarthrosis after anterior cervical diskectomy and fusion were reviewed. Standardized outcome measures such as visual analog scale (VAS) score for neck and arm pain, Neck Disability Index (NDI), and upright lateral cervical radiographs were reviewed.
  
  
  RESULTS
  There were 19 patients with symptomatic cervical pseudarthrosis. Preoperative symptoms included refractory neck or arm pain. The average follow-up was 20 months (range, 12-56 months). There was improvement in VAS score for neck pain (P < .004), radicular arm pain (P < .007), and NDI score (P < .06) after surgery, with 83%, 72%, and 67% of patients showing improvement in their VAS neck pain, VAS arm pain, and NDI scores, respectively. Fusion rate was high, with fusion occurring at all levels treated for pseudarthrosis. There was a small improvement in cervical lordosis (mean difference, 2 ± 5.17°; P = .09) and slight worsening of C2-7 sagittal vertical axis after surgery (mean difference, 1.89 ± 7.87 mm; P = .43).
  
  
  CONCLUSIONS
  CIS provides an important fusion technique, allowing placement of an allograft in compression for posterior cervical fusion in patients with anterior cervical pseudarthroses. Although there was improvement in clinical outcome measures after surgery, placement of CIS had no clinically significant impact on cervical lordosis and C2-7 sagittal vertical axis.
authors.affiliation: Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois.
authors.forename: Manish K
authors.initials: MK
authors.lastname: Kasliwal
authors.forename: Jacquelyn A
authors.initials: JA
authors.lastname: Corley
authors.forename: Vincent C
authors.initials: VC
authors.lastname: Traynelis
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D004185:Disability Evaluation; D017586:Diskectomy; D005260:Female; D006801:Humans; D016268:Internal Fixators; D008141:Lordosis / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000601:surgery / Q000628:therapy; D010147:Pain Measurement; D011542:Pseudarthrosis / Q000000981:diagnostic imaging / Q000601:surgery*; D012189:Retrospective Studies; D013122:Spinal Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*; D016896:Treatment Outcome; D021801:Zygapophyseal Joint / Q000000981:diagnostic imaging / Q000601:surgery*