Obesity and anterior lumbar interbody fusion: a bayesian meta-analysis of complications and outcomes

Samir Smajic; Koroush Kabir; Ümit Mert; Markus Konieczny; Ghasemi Amir; Raffael Scrofani; Filippo Migliorini; Anel Dracic

doi:10.1007/s00586-025-09673-4

Obesity and anterior lumbar interbody fusion: a bayesian meta-analysis of complications and outcomes

Eur Spine J. 2025 Dec 22. doi: 10.1007/s00586-025-09673-4. Online ahead of print.

Authors

Samir Smajic^{1

2}, Koroush Kabir^{3

4}, Ümit Mert^{3

4}, Markus Konieczny⁵, Ghasemi Amir³, Raffael Scrofani⁶, Filippo Migliorini⁷, Anel Dracic^{8

9}

Affiliations

¹ Clinic for Spine Surgery, Artemed Hospital Düren, Düren, Germany. dr.med.smajic@gmail.com.
² Faculty of Health/School of Medicine Witten/Herdecke University, Witten, Germany. dr.med.smajic@gmail.com.
³ Faculty of Health/School of Medicine Witten/Herdecke University, Witten, Germany.
⁴ Department of Trauma and Orthopaedic Surgery, Helios University Hospital, University Wuppertal, Wuppertal, Germany.
⁵ Orthopaedic Clinic Volmarstein, Wetter, Germany.
⁶ Department of Clinical Neurosurgery, AOU San Giovanni di Dio e Ruggi D´Aragona, University of Salerno, Salerno, Italy.
⁷ Department of Orthopaedics and Trauma Surgery, Academic Hospital of Bolzano (SABES-ASDAA), Bolzano, Italy.
⁸ Faculty of Health/School of Medicine Witten/Herdecke University, Witten, Germany. aneldracic@gmail.com.
⁹ Orthopaedic Clinic Volmarstein, Wetter, Germany. aneldracic@gmail.com.

PMID: 41428061
DOI: 10.1007/s00586-025-09673-4

Abstract

Purpose: To determine whether obesity (body mass index ≥ 30 kg/m²) is associated with differences in complication rates, operative parameters, pain/disability outcomes, and hospital length of stay after anterior lumbar interbody fusion (ALIF) for degenerative lumbar pathology.

Methods: We conducted a systematic review and Bayesian meta-analysis following PRISMA 2020. PubMed, Embase, and Scopus were searched from January 1, 2010, to April 1, 2025, for retrospective or prospective studies comparing obese versus non-obese ALIF cohorts. Two reviewers independently screened studies, extracted data, and assessed risk of bias using the Newcastle-Ottawa Scale. A hierarchical Bayesian framework synthesized continuous outcomes (Visual Analog Scale [VAS] for back/leg pain, Oswestry Disability Index [ODI], hospital stay, blood loss, operative time) and binomial complication data. Sensitivity analyses excluded a large supine-position study and varied prior distributions.

Results: Twenty-two studies met inclusion criteria. Obesity was associated with higher odds of complications (median odds ratio ≈ 1.5; 95% credible interval [CrI] 1.1-2.0) and longer hospital stay (mean difference ≈ + 1.3 days; 95% CrI + 0.8 to + 1.9). Postoperative pain modestly favored non-obese patients: back pain mean difference ≈ + 0.4 points (95% CrI 0.0 to + 0.8) and leg pain ≈ + 0.8 points (95% CrI + 0.4 to + 1.2) in obese cohorts. ODI effects showed substantial between-study heterogeneity. Blood loss and operative time findings were inconclusive due to high variability across centers. Sensitivity analyses preserved effect direction.

Conclusion: Obesity modestly increases complication risk and length of stay after ALIF, yet obese patients still achieve meaningful postoperative pain relief. Preoperative risk-factor optimization, careful exposure strategies, and multidisciplinary perioperative care may mitigate these risks. Further prospective research with standardized outcome definitions is warranted to refine patient selection and surgical technique.

Keywords: Bayesian meta-analysis; Degenerative lumbar disease; Obesity; anterior lumbar interbody fusion (ALIF).

Publication types

Review