[Lumbar interbody fusion with threaded titanium cages. Results on 222 cases]

Retrospective analysis of 222 cases of degenerative disc disease treated by threaded cage fusion. The objective was to determine the safety and efficiency of lumbar interbody fusions using screwed titanium cages and autogenous bone. Two hundred twenty-two patients had lumbar fusion at 243 levels between L2 and S1, at one or two disc spaces. Main indication was discogenic back pain with radicular leg radiation in degenerative discopathy complicated by disc protusion, segmental canal stenosis with chronic instability or spondylolysthesis of the first degree. Previous failed surgery after discectomy, nonunion or biologically cured discitis were other indications in selected cases. Results were classified as good to excellent in 80%, 15% improved but remained disabled, 5% had minimal or no improvement. Fusion rate was 91% at one year and 96% at 2 years. Peroperative dural tears occurred in 10 patients and transient neurological deficits in 9. A superficial infection occurred in one patient. Reoperation in the first three months included a cage revision in one patient and a foraminotomy in another. Two osteoporotic women needed an additional posterior fixation for kyphotic deformity. In conclusion, lumbar interbody fusion with threaded titanium cages appears to be efficacious with an acceptable rate of complications. Experience up to 7 years confirms that impression. Long term observation is needed before recommending this new method.