Evaluating the impact of body-mass index on short- and medium-term outcomes after lumbar endoscopic decompression surgery: a single‑surgeon, multi‑hospital cohort study.

PURPOSE: To evaluate the influence of Body Mass Index (BMI) on short- and medium-term outcomes following endoscopic spinal surgery.

METHODS

In this retrospective study, 294 patients who underwent surgery between August 2021 and June 2024 were identified; 189 met inclusion criteria. Outcomes assessed were the Visual Analogue Scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (RMDQ), and EQ-VAS at 12 weeks and last follow-up (9–12 months). Statistical analyses included Spearman’s correlations, baseline-adjusted multivariable linear regression, and minimal clinically important difference (MCID) assessment. BMI was analysed primarily as a continuous variable and secondarily as a categorical variable. Between-group differences in improvement were visualised using a shared-control estimation plot.

RESULTS

Mean BMI was 29.4 kg/m2, with 38% classified as overweight (25–29.9 kg/m²) and 43% as obese (≥ 30.0 kg/m²). At 12 weeks, higher BMI was associated with less improvement in VAS leg pain (ρ = −0.178, p = 0.043) and ODI (ρ = −0.173, p = 0.044), while no significant associations were observed for the remaining outcome measures. By last follow-up, BMI was not associated with improvement in any measure. Estimation plot and multivariable regression indicated no significant BMI-related differences in medium-term improvement. MCID achievement rates were comparable across BMI categories.

CONCLUSION

Higher BMI was associated with modestly reduced short-term improvements, but these differences diminished by last-follow-up. BMI did not strongly predict medium-term outcomes. Endoscopic spinal surgery appears viable across BMI categories, although obesity should be considered a modifiable factor for optimising early postoperative recovery.