title: Expandable cylindrical cages in the cervical spine: a review of 22 cases.
abstract: OBJECTIVE
  Expandable cylindrical cages (ECCs) have been utilized successfully to reconstruct the thoracic and lumbar spine. Their advantages include ease of insertion, reduced endplate trauma, direct application/maintenance of interbody distraction force, and one-step kyphosis correction. The authors present their experience with ECCs in the reconstruction of the cervical spine in patients with various pathological conditions.
  
  
  METHODS
  Data obtained in 22 patients were reviewed retrospectively. A standard anterior cervical corpectomy was performed in all cases. Local vertebral body bone was harvested for use as graft material. Patients underwent pre- and postoperative assessment involving the visual analog scale (VAS), Nurick grading system for determining myelopathy disability, and radiographic studies to determine cervical kyphosis/lordosis and cage subsidence. Fusion was defined as the absence of motion on flexion-extension x-ray films. Sixteen patients presented with spondylotic myelopathy, two with osteomyelitis, two with fracture, one with tumor metastasis, and one with severe stenosis. Fourteen patients underwent supplemental posterior spinal fusion, seven underwent single-level corpectomy, and 15 patients underwent multilevel corpectomy. No perioperative complications occurred. The mean follow-up period was 22 months. In 11 patients with preexisting kyphosis (mean deformity +19 degrees), the mean correction was 22 degrees. There was no statistically significant difference in subsidence between single- and multilevel corpectomy or between 360 degrees fusion and anterior fusion alone. The VAS scores improved by 35%, and the Nurick grade improved by 31%. The fusion rate was 100%.
  
  
  CONCLUSIONS
  The preliminary results support the use of ECCs in the cervical spine in the treatment of patients with various disease processes. No significant subsidence was noted, and pain and functional scores improved in all cases. Expandable cylindrical cages appear to be well suited for cervical reconstruction and for correcting sagittal malalignment.
authors.affiliation: Department of Neurological Surgery, Brain Tumor Research Center, University of California, San Francisco School of Medicine, San Francisco, California 94143-0112, USA.
authors.forename: Kurtis I
authors.initials: KI
authors.lastname: Auguste
authors.forename: Cynthia
authors.initials: C
authors.lastname: Chin
authors.forename: Frank L
authors.initials: FL
authors.lastname: Acosta
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000601:surgery*; D005260:Female; D006801:Humans; D016268:Internal Fixators; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D012189:Retrospective Studies; D013122:Spinal Diseases / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation*; D016896:Treatment Outcome