Segmental polymethylmethacrylate-augmented fenestrated pedicle screw fixation for lumbar spondylolisthesis in patients with osteoporosis - A case series and review of literature.

Abstract

Instrumentation in patients with osteoporosis is challenging. Bone cement-augmented fenestrated pedicle screw fixation is a new procedure for fixation in osteoporotic bone. Very few studies related to this procedure are published in literature. To evaluate the clinical and radiological outcome of polymethylmethacrylate (PMMA)-augmented fenestrated pedicle screw fixation in patients with spondylolisthesis having significant osteoporosis. This was a prospective, observational, single centre study. All the patients with lumbar spondylolisthesis and osteoporosis with symptomatic neural compression, managed surgically with PMMA-augmented fenestrated pedicle screws, were included in the study. Patients were evaluated preoperatively and postoperatively by means of Oswestry disability index (ODI), visual analog score (VAS); and, radiologically by plain radiography and computed tomography. Wilcoxon nonparametric test for paired samples with a level of significance of 0.05 was performed. A total of 25 patients of spondylolisthesis with osteoporosis (average T score of -3.0) were included in the study. The average age at presentation was 56.5 years. Females predominated with a female:male ratio of 3.16:1.Most of the patients had spondylolisthesis at the L4/L5 level followed by the L5/SI level. All the patients underwent spinal fusion with instrumentation and bone cement (PMMA)-augmentation through fenestrated cannulated pedicle screws. Preoperative and postoperative functional assessment done with VAS and ODI showed statistically significant improvement. All the patients had an evidence of bone fusion at follow-up. Fenestrated pedicle screw fixation with bone cement-augmentation in patients with lumbar spondylolisthesis and osteoporosis provided effective and lasting screw purchase.