Risk factors for poor functional outcomes at one year in biportal endoscopic spine surgery for lumbar spinal stenosis.

PURPOSE: This study aims to identify preoperative and intraoperative factors associated with poor functional outcomes at one year following biportal endoscopic spine surgery (BESS) for lumbar spinal stenosis. BESS is a minimally invasive option for lumbar spinal stenosis. While clinical outcomes are generally favorable, identifying risk factors for poor recovery is essential for patient selection and surgical planning.

METHODS

A retrospective review was conducted on 168 patients who underwent BESS between 2019 and 2023. Poor functional outcome was defined as < 50% improvement in the Visual Analog Scale (VAS) or < 40% improvement in the Oswestry Disability Index (ODI) at one year. Potential predictors, including age, sex, BMI, comorbidities, and radiographic severity of stenosis, were analyzed using multivariable logistic regression to identify independent risk factors.

RESULTS

Clinical success was achieved in 79.2% of patients. Multivariable analysis identified BMI ≥ 25 (OR = 3.00, 95% CI: 1.33–6.76, p = 0.008) as an independent predictor of poor outcomes. Other variables, including age ≥ 65 years, diabetes mellitus, hypertension, and intraoperative blood loss, were not statistically significant. Postoperative complications occurred in 3% of patients, all managed conservatively.

CONCLUSION

Elevated BMI is a significant independent risk factor for poor functional recovery following BESS. Thorough preoperative assessment and careful surgical planning in these patients may help improve clinical outcomes.