The impact of semaglutide use for weight loss on transforaminal lumbar interbody fusion outcomes.

INTRODUCTION: While glucagon-like peptides 1 receptor agonists (GLP-1RAs) grow in popularity, their potential for presurgical weight optimization in spine surgery remains unclear. We examined the influence of semaglutide prescription on one- to three-level transforaminal lumbar interbody fusion (TLIF) outcomes. METHODS: Retrospective analysis of obese, non-diabetic patients was conducted from 2018 to 2022. A 1:1 exact match paired semaglutide users with non-users based on age, gender, surgical levels, and comorbidities. The primary outcome were the rates of surgical and medical complications at 30 days following TLIF. A sub analysis assessed outcomes after stratifying by prescription duration (greater or less than nine months). Kaplan-Meier survival analyses evaluated the need for additional lumbar fusion. The alpha was set to 0.05, but with the Bonferroni correction the significance threshold was set to 0.0045. RESULTS: 471 semaglutide users were matched with 471 non-users with no baseline differences. Semaglutide users had higher rates of pneumonia (2.97 % vs 0.85 %, p < 0.05) compared to nonusers. When stratified by prescription duration, patients with longer semaglutide use had a higher incidence of urinary tract infection (4.03 % vs 1.27 %, p < 0.05) and acute kidney injury (3.18 % vs 0.85 %, p < 0.05). The need for additional lumbar fusion was associated with both semaglutide use (17.0 % vs. 6.4 %, p < 0.0001) and duration (28.3 % vs. 4.8 %, p < 0.0001). CONCLUSIONS: Semaglutide may adversely affect lumbar fusion outcomes and necessitate additional surgery, possibly secondary to its systemic effects on bone metabolism and weight loss patterns. Further research into optimal drug formulation, dosage, and weight loss protocols will be required before mainstream use.