Urinary dysfunction following single-level lumbar fusion in men: A propensity-matched analysis of surgical approach

Background: Urinary dysfunction remains an underrecognized complication of spine surgery, despite its potential impact on postoperative quality of life. However, comparative data evaluating urinary outcomes by surgical approach among men undergoing single-level lumbar fusion remain limited. This study compared postoperative urinary dysfunction following anterior-only versus posterior-only single-level lumbar fusion. Methods: The TriNetX Research Network was queried to identify adult men who underwent single-level lumbar fusion between 2010 and 2023 with preoperative diagnoses of lumbar, lumbosacral, or thoracolumbar stenosis, spondylolisthesis, scoliosis, myelopathy, or radiculopathy. Patients were categorized by surgical approach as anterior-only or posterior-only fusion. Individuals with complex spinal pathology, preexisting urogenital disease, prior alternative exposure, or nonlumbar involvement were excluded. Propensity score matching balanced demographics and relevant comorbidities. The primary outcome was a composite of postoperative urinary complications assessed at 1, 3, 6, 9, and 12 months after surgery. Results: Of 12,369 eligible patients, 10,606 underwent posterior-only fusion and 1,763 underwent anterior-only fusion. After 1:1 propensity score matching, 1,761 well-balanced patients comprised each cohort. Relative to anterior-only fusion, posterior-only operations were associated with significantly higher odds of urinary complications at 1-month (odds ratio [OR] 1.84, 95% confidence interval [CI] [1.23–2.77]), 3-month (OR 1.86, 95% CI [1.29–2.70]), 6-month (OR 1.91, 95% CI [1.35–2.71]), 9-month (OR 1.65, 95% CI [1.21–2.27]), and 12-month (OR 1.49, 95% CI [1.10–2.00]). Conclusion: In this multi-institutional cohort of men undergoing single-level lumbar fusion, posterior exposure was associated with substantially higher odds of urinary dysfunction throughout the first postoperative year, suggesting the surgical approach may be an important determinant of postprocedural urinary outcomes.