Predictors of decompression failure in lumbar spinal stenosis: A Systematic Review and Meta-analysis

Introduction: Lumbar spinal stenosis (LSS) primarily affects older adults and is often caused by degenerative disc disease, with surgery offering relief for non-responsive cases. Despite advancements in minimally invasive techniques, patient selection remains critical due to the potential for poor outcomes, especially in patients with severe stenosis, low bone density, or prolonged back pain. This highlights the need for improved predictive models to guide surgical decisions and reduce the risk of postoperative disability, indicating a gap in optimizing outcomes for LSS surgery. Our aim is to identify and evaluate predictive factors for failure and worsening of outcomes after lumbar spine decompression in lumbar spine surgery, assessing functional and clinical outcomes in degenerative spinal disease.

Methods: A systematic review was conducted using PRISMA guidelines to evaluate the literature on clinical and radiological predictors of decompression failure in lumbar spinal stenosis surgery. Studies from inception to October 2024 were systematically screened from five databases. Data regarding study design, patient demographics, procedure characteristics, and clinical and radiological outcomes were collected. A meta-analysis compared predictors associated with successful and unsuccessful decompression outcomes.

Results: Out of 4,096 studies, 29 met the inclusion criteria, comprising 20,676 patients. The included studies primarily consisted of adults with a mean age of around 70 years and a BMI above 25. Approximately 20-27% of participants had an ASA grade above 2. Chronic pain was prevalent, with up to 70% experiencing back pain for over a year. Comparative analyses identified age as a statistically significant predictor; as age increased, the likelihood of failure outcomes also increased. The overall effect size, represented by Cohen’s d, was 0.16, with a confidence interval ranging from 0.04 to 0.27 (p = 0.01). No significant differences were observed for BMI or preoperative ODI.

Conclusion : This review found significant results for age as a predictor associated with worse functional outcomes in elderly patients. No other predictors showed a significant association with failure, highlighting the need for more consistent research to identify additional risk factors for poor outcomes.