Transforaminal lumbar interbody fusion in iatrogenic lumbar instability

Background Lumbosacral instability is one of the causes of failed back surgery syndrome, and it is characterized by loss of disc height with translational and in many cases rotational instability in the sagittal plane. Transforaminal lumbar interbody fusion (TLIF) is a modification of posterior lumbar interbody fusion that requires less retraction of the thecal sac and neural element. TLIF corrects most of the pathologies in patients with iatrogenic lumbar instability as it provides rigid stabilization of the spine with high incidence of fusion, decompression of central and lateral recess with facet and disc resection, restoration of disc and foraminal heights together with sagittal plane deformity correction. Aim This study was carried out to evaluate the efficacy of TLIF in the treatment of patient with iatrogenic lumbar instability. Patients and methods A total of 16 cases were diagnosed as iatrogenic lumbar instability according to the radiological method proposed by Dupuis and colleagues. Sex distribution was nine females and seven males. Plain radiograph (static and dynamic) and MRI with gadolinium enhancement were done for all patients. Single-level transforaminal lumbar interbody fusion (TILF) was performed in 11 cases and double-level TLIF was performed in five cases. Clinical evaluation was made using Oswestry disability index. Patients were examined for occurrence of solid interbody fusion at 9- and 12-month follow-up visits. Result A total of 14 patients showed obvious clinical improvement with reduction of their Oswestry disability index from 76.75% preoperatively to 36.9% at 6 month and 22.7% after 1 year. Overall, two cases had shown no clinical improvement: one had deep wound infection and the other had pseudoarthrosis. Solid fusion occurred in 14 (87.5%) cases. One case with pseudoarthrosis was the patient who had developed deep wound infection; the other case was a patient undergoing double-level TILF with pseudoarthrosis at L5–S1. Conclusion TLIF is a safe and effective technique in the treatment of patients with postlaminectomy lumbar instability with minimal complication rate.