Minimally invasive transforaminal lumbar interbody fusion using bone cement-augmented pedicle screws for lumbar spondylolisthesis in patients with osteoporosis. Case series and review of literature.

BACKGROUND: Instrumentation in patients with osteoporosis is challenging. Bone cement-augmented fenestrated pedicle screw fixation is a new procedure for fixation in the osteoporotic bone; and, applying minimally invasive techniques to the above is a challenging and novel concept. AIMS: To evaluate the clinical and radiological outcome of minimally invasive spine surgery transforaminal lumbar interbody fusion (MIS-TLIF) in patients with spondylolisthesis and poor bone quality, performed with rigid instrumentation using bone cement [poly(methylmethacrylate)]-augmented fenestrated pedicle screws. SETTINGS AND DESIGN: Prospective, observational, single-center study. STATISTICAL ANALYSIS USED: Wilcoxon nonparametric test for paired samples with a level of significance of 0.05. METHODS: A clinical series of 25 patients with lumbar spondylolisthesis and osteoporosis who underwent minimally invasive TLIF with bone cement-augmented pedicle screws were included in the study. Clinical outcome and the function were assessed using the visual analog scale (VAS) score for pain and the Oswestry Disability Index (ODI). Perioperative, postoperative, and long-term complications were monitored with a mean follow-up of 18 months. RESULTS: A total of 25 (20 female and 5 male) patients were included in the study with an average age of 61.05 years. The major symptom was low back pain with radiating pain to lower limbs. The average T-score was -3.0. All the patients were followed clinically and radiologically. There was a statistically significant improvement in the VAS scores and ODI scores postoperatively. No events of cement extravasation, radiological loosening, or pulling out of screws were observed. CONCLUSIONS: Fenestrated pedicle screw fixation with bone cement augmentation in patients with osteoporosis is a well-established alternative to increase the pullout strength of screws placed in the osteoporotic bone. Applying the concept of minimally invasive surgery to this procedure makes it a more complete solution for instrumentation in osteoporotic spine. Our series is the largest in literature on spondylolisthesis and confirms the feasibility and safety of this procedure in treating spondylolisthesis in the aging population.

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

BACKGROUND: 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. AIMS: To evaluate the clinical and radiological outcome of polymethylmethacrylate (PMMA)-augmented fenestrated pedicle screw fixation in patients with spondylolisthesis having significant osteoporosis. SETTINGS AND DESIGN: This was a prospective, observational, single centre study. MATERIALS AND METHODS: 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. STATISTICAL ANALYSIS: Wilcoxon nonparametric test for paired samples with a level of significance of 0.05 was performed. RESULTS: 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. CONCLUSION: Fenestrated pedicle screw fixation with bone cement-augmentation in patients with lumbar spondylolisthesis and osteoporosis provided effective and lasting screw purchase.