Comparison of functional outcomes in patients with lumbar canal stenosis with and without obesity treated with lumbar decompression surgery

Objective The rising prevalence of obesity has raised concerns about its impact on surgical outcomes. Obesity is a critical risk factor of low back pain and lumbar degeneration diseases, but it is still unclear whether obesity is related to lumbar surgical outcomes in the Chinese population. This study examines the influence of body mass index (BMI) on the clinical effectiveness of lumbar decompression surgery in patients with lumbar canal stenosis (LCS). Methods 465 patients with single-segment LCS treated with lumbar decompression surgery at the LiHuiLi Hospital between April 2018 and August 2023 were enrolled in this study. Patients were divided into obesity (OB, BMI > 30 kg/m²) and non-obesity (NOB, BMI < 24 kg/m²) groups. Baseline data, operation time (OT), hospital stay (HS), Visual Analogue Scale (VAS) scores, Oswestry Disability Index (ODI), and maximum walking distance (MWD), C-reaction protein (CRP), white blood cell (WBC), complications, and reoperations were evaluated. Results Of the total participants, 156 were categorized as OB and 309 as NOB. The NOB group exhibited significantly greater improvement in VAS scores at 1 month and ODI scores at 3 and 12 months postoperatively ( P < 0.001). The OB group had significantly lower MWD both preoperatively and at the final follow-up compared to the NOB group ( P < 0.001). The OB group also had significantly longer OT and HS ( P < 0.001), as well as higher rates of complications and reoperations compared to the NOB group ( P < 0.05). Linear regression revealed a significant relationship between BMI and MWD ( P < 0.001). Conclusions Obesity maybe associated with poorer functional recovery, increased complications, and prolonged recovery following lumbar decompression surgery.