NS13P A PROSPECTIVE COMPARISON OF TWO CERVICAL INTERBODY FUSION CAGES

Purpose  For some time the surgical management of chronic back pain has utilised interbody lumbar cages. Recently interbody cages for use in the cervical spine have been produced. Cervical cages provide initial stability during the fusion process. There is little literature comparing the performance of interbody cage systems due to their relative recent introduction. Methodology  Patients with symptomatic cervical degeneration or traumatic lesions were treated with the dynamic ABC 2 Aesculap anterior cervical plating system and either the B-Braun Samarys or Zimmer cage systems. A single surgeon conducted all surgery. Pre- and post-operative radiological examinations were compared. Changes in disc height at affected and adjacent levels, lordosis and evidence of fusion were recorded. Patient outcome was measured with questionnaires. The modified Oswestry neck pain disability and Copenhagen neck disability scale scores were utilised to allow comparison between patients. Results  A total of 43 patients were involved in the study (30 with the Zimmer cage system and 13 with the Samarys cage). Patient follow-up has been up to 12 months. Improvement in disability scores was shown in 90% of patients. Follow up imaging did not demonstrate subsidence of the cage or adjacent instability in either group. There was no statistical difference in complication rate between the two groups. Discussion  Initial stability was provided by both interbody cervical spine cage system. Rates of fusion and symptomatic relief compared favourably to fusion involving autogenous bone graft without associated morbidity. Longer follow up is necessary to determine whether there is evidence of adjacent level instability or vertebral end-plate subsidence.