GLP-1 Agonists' Effect on Infection and Union after Tibiotalar Fusion, Subtalar Fusion, Triple Arthrodesis

GLP-1 agonist use has increased due to the rising prevalence of obesity and diabetes mellitus. Foot and ankle surgeons provide orthopaedic care to diabetic patients. The effects of GLP-1 agonists on foot fusion outcomes are not well explored.

The TriNetX Global Collaborative Network was queried using CPT codes for patients with diabetes mellitus undergoing open tibiotalar fusions, subtalar fusions, and triple arthrodesis. Outcomes were assessed at 1 year after index surgical procedure. Cohort balancing was performed according to age at procedure, race, sex, and nicotine dependence, for body mass index, glycated hemoglobin (HbA_1c), and estimated glomerular filtration rate (eGFR). Statistical significance was set at P <.05 with associated 95% CIs.

Two cohorts of 783 patients undergoing tibiotalar, subtalar, or triple arthrodesis fusions were compared using CPT coding in this study (Table 1). Among patients treated with GLP-1 agonists, the overall rate of postoperative pseudarthrosis was found to be lower (15.9% vs 20.2%, P = .0129, RR 1.26 (1.02-1.56). Comparison of constituent procedures in isolation showed a lower rate of pseudarthrosis for patients using GLP-1 agonist than matched controls: subtalar fusion (17.2% vs 23.4%, P = .0292, RR 1.36, 95% CI 1.03-1.79) and triple arthrodesis (12.4% vs 21.9%, P = .0120, RR 1.76, 95% CI 1.12-2.76). No significant difference was found in rates of pseudarthrosis after tibiotalar fusion (19.8% vs 21.5%, P = .5692, RR 1.09, 95% CI 0.81-1.46). No difference was detected in postoperative infection rates for any of the procedure types (Table 3).

Results suggest a previously unreported better fusion rates associated with GLP-1 agonist use after fusion procedures of the foot and ankle. This study also shows no clear risk or benefit associated with GLP-1 agonists with respect to postoperative infection. Additional clinical studies are needed to clarify this association.