Effect of Surgical Approach on Spondylolisthesis Surgery and Associated Patient Reported Outcomes: A Retrospective Review

Introduction: Lumbar spondylolisthesis often leads to pain and disability, necessitating surgical intervention. While prior research has explored how body mass index (BMI) affects outcomes following lumbar fusion, the impact of different surgical approaches, specifically transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF), across BMI categories is unclear. This study evaluates patient-reported outcomes (PROs) following TLIF and LLIF in low-grade degenerative and isthmic spondylolisthesis, with a focus on BMI stratification.

Methods: This retrospective cohort study includes patients with low-grade degenerative and isthmic spondylolisthesis who underwent lumbar fusion from 2010 to 2023. Patients are stratified by BMI into non-obese ( < 30), class I (30-34.9), class II (35-39.9), and class III (≥40). Outcomes are assessed using the Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) at baseline and 12 months. The study compares the achievement of minimal clinically important difference (MCID) between TLIF and LLIF across BMI groups.

Results: Seventy-two patients were analyzed, with significant improvements in ODI (mean change: 17.0; p < .001) and VAS (mean change: 2.3; p < .001) observed across all BMI categories at 12 months. TLIF achieved MCID in 70.8% of patients, while LLIF achieved MCID in 68.5%, with no statistically significant differences in overall outcomes between the techniques (p = .72). Non-obese and class II patients demonstrated sustained improvements in disability, achieving MCID for ODI (mean change: 19.8; p < .01) and VAS (mean change: 3.1; p < .05), while class III patients showed initial gains that plateaued at 12 months (mean ODI change: 11.6; p = .21). Perioperative metrics, including operative time and blood loss, were comparable between the two approaches across BMI categories.

Conclusion : Lumbar fusion using TLIF and LLIF effectively reduces disability and pain across BMI categories, suggesting that obesity should not be a contraindication for fusion. The choice of surgical approach should be based on patient-specific factors, such as anatomy and comorbidities, rather than BMI. Future prospective studies with longer follow-up are necessary to further clarify the long-term outcomes of TLIF and LLIF across BMI groups.