Rationale for interbody fusion with threaded titanium cages at cervical and lumbar levels.: Results on 357 cases

Study Design. Retrospective analysis of 357 cases of degenerative disc disease treated by interbody fusion with threaded titanium cages. Objective. To determine the safely and efficiency of cervical and lumbar interbody fusions using threaded titanium cages and autogenous bone. Summary of Background Data. Stabilizing the anterior column by interbody fusion, though reported over 50 years ago, is less commonly done than posterior fusions. The recent development of rigid cages housing autogenous bone simplifies the technique of interbody fusion. This report shows our combined results using this technique. Materials and Method's. One hundred thirty-five patients had cervical fusions at 175 levels between C3 and C7. Two hundred twenty-two patients had lumbar fusion at 243 levels between L2 and S1. All surgeries involved one or two disc spaces except for one three level cervical fusion. We implanted all disc spaces with threaded cages containing autogenous bone. Results. In the cervical area, 95% of the radiculopathic patients had a good to excellent result, but only 50% of the myelopathic patients did so. At lumbar level, 80% of the patients were classified as good to excellent, 15% improved but remained disabled, 5% had minimal or no improvement. The cervical fusion rate was 90% at 6 months and 100% at one year. Lumbar fusion rate was 91% at one year and 96% at 2 years. No late breakage or cage displacement occurred. Conclusions. Cervical and lumbar interbody fusions with threaded titanium cages appear to be efficacious with few complications. Long term follow-up (4 years cervical, 7 years lumbar) confirms that impression.