PURPOSE: To evaluate incidental lumbar durotomy incidence and risk-factors, and the association of durotomy with perioperative metrics and patient-reported outcomes. METHODS: A total 3140 cases of 1-3 level elective decompressive surgery from 2008 to 2023 at a single centre were included. Multivariable analysis was performed on literature derived variables to identify independent risk-factors for durotomy. Absolute difference or absolute risk increase (ARI) between durotomy and non-durotomy perioperative metrics was calculated. The association between durotomy and 3-month or 12-month patient-reported outcome measures was assessed. RESULTS: All-procedure durotomy incidence was 4.5% (142/3140). Durotomy risk-factors were age (odds ratio (OR) 1.016, 95% confidence intervals (95% CI) 1.011-1.020), female (OR 1.48, 95% CI 1.26-1.74), number of operative levels (two-level OR 1.81, 95% CI 1.48-2.21
three-level OR 3.18, 95% CI 2.14-4.72), multiple versus no previous operation (OR 1.85, 95% CI 1.11-3.07), and fusion with discectomy versus discectomy (OR 2.36, 95% CI 1.90-2.93). Durotomy was associated with longer length of stay (∆2.4 days, p <
0.001), longer operative time (∆21 min, p <
0.001), and higher rate of iatrogenic nerve injury (ARI 4.3%, p <
0.001), 30-day return to theatre (ARI 5.7%, p <
0.001), and 30-day readmission (ARI 4.4%, p = 0.002). Durotomy was not associated with poorer patient-reported outcomes. CONCLUSION: Dural tears are often under-reported and are associated with longer hospital stay, increased operative time, and rare perioperative complications which increase healthcare costs. Dural tears did not, however, detrimentally affect patient-reported disability or pain outcomes.