Spine surgeons want to know whether these drugs help or hinder a bone fusion — a question adjacent to whether to pause them around an operation and separate from it. The published evidence answers both ways at once, and the way this review handles that is more instructive than any of its numbers.
What was gathered
Twelve retrospective cohorts, all published in 2025 or 2026, on GLP-1 exposure and outcomes after cervical fusion, searched across five databases to June 2026. [1] The primary outcome was pseudarthrosis — the fusion failing to knit.
For anterior cervical discectomy and fusion, a combined estimate from one large claims network put the odds of failed fusion lower among GLP-1 users, OR 0.52, 95% CI 0.40 to 0.67. An independent estimate from a different network was neutral, OR 0.86, 95% CI 0.56 to 1.32. The anterior subgroup as a whole came to 0.65, 95% CI 0.40 to 1.06, with heterogeneity of 74.5%.
A semaglutide-specific posterior cervical fusion cohort went the other way entirely: OR 4.79, 95% CI 3.11 to 7.37 for failed fusion at two years, with a dysphagia signal alongside it.
Twelve studies, fewer than twelve samples
This is the part worth carrying away. Several of the included cohorts query the same commercial claims networks, so the same patient can appear in more than one apparently independent study. A reader counting twelve papers on a subject may be looking at far fewer distinct groups of people.
The authors prespecified how to handle double counting and used non-overlapping estimates for the primary synthesis. That is careful work and it is rare — most reviews in this literature simply count the papers. The rise of large shared claims networks means the problem is getting worse, not better, and it affects every study built on the same data.
Why the direction might genuinely differ
Anterior and posterior cervical fusion are different operations with different biology and different failure modes. It is entirely plausible that a drug affects one and not the other, or affects them oppositely, and the authors take that position explicitly.
It is also possible that the posterior finding reflects who gets a posterior fusion — generally more complex disease, more levels, more comorbidity. One cohort in one procedure is thin ground for a fourfold estimate, and the review classes all of this as hypothesis-generating rather than actionable. The distance between a pooled figure and a patient is rarely this visible.
What it means before an operation
That the question is live and unsettled, and that your surgeon should be told you are taking one of these drugs. Whether to pause it around surgery is a separate question, and the evidence there is mostly about anesthesia rather than about bone.
No seller on this roster asks whether you have surgery scheduled, and none would know what to do with the answer — the census of what goes unasked counts how much a prescription arrives without. Anybody facing a fusion should raise it with the surgeon who will do it.