Effect of interbody fusion cage on clinical and radiological outcome of surgery in L4-L5 lumbar degenerative spondylolisthesis.

Background: Lumbar degenerative spondylolisthesis (LDS) is a degenerative slippage of a lumbar vertebra relative to the adjacent vertebra below that can be clinically symptomatic. We aim to compare radiological and clinical outcome of surgery in L4-L5 LDS with or without applying the interbody fusion cage.

Methods: We studied 60 patients (mean age, 51.3±13.2 years; follow-up, 53.3±14.6 months) with L4-L5 LDS who had been treated by decompression, pedicle screw and rod instrumentation associated with posterolateral fusion (PLF) without and with transforaminal lumbar interbody fusion (TLIF) in equally divided groups A and B, respectively. Intraoperative parameters were recorded and outcome assessment carried out by visual analog scale (VAS), Oswestry Disability Index questionnaire (ODI), subjective satisfaction, radiologic union, and loss of reduction. We judged the differences by -test and cross-tab.

Results: Using an interbody fusion cage was associated with a significant increase in intraoperative blood loss, operative time, and instrument cost. Improvement in VAS and ODI were significant but comparable. Satisfaction rate was higher in group A (P=0.52). Fusion rate and loss of correction were more favorable in group B but these differences were not significant.

Conclusions: In the surgical treatment of the patients with L4-L5 LDS, interbody fusion cage probably does not significantly improve the radiologic and clinical outcomes and may also be associated with more complication and morbidity.