Background: A common complication of lumbar spine surgery is incidental tear of the dural sac and subsequent leakage of the cerebrospinal fluid intraoperatively. Studies have reported a wide variation in the rates of dural tears in spine surgery (1%–17%). The rates were higher after revision surgery.

Objective: To establish a baseline rate of incidence of dural tears after lumbar surgery in Morriston Hospital Neurosurgical Unit and to compare it with the results reported in the literature.

Methods and Results: A prospective review of the operation notes of 65 consecutive patients who had undergone lumbar surgery (Primary lumbar discectomy, primary lumbar laminectomy and revision lumbar discectomy) over a period of 3 months from Jan 2008. Patients were operated on by different neurosurgical consultants.

40 patients had primary lumbar discectomy of which 2 (5%) had dural tears. 20 patients had primary lumbar laminectomy of which 1 (5%) had a dural tear and 5 patients had revision lumbar discectomy of which 1 (20%) had a dural tear. All dural tears were repaired intraoperatively.

Conclusion: This study shows that the highest percentage of incidental durotomy was in revision lumbar surgery which was also slightly higher than the reported rates (8.1%–17.4%). The percentage of dural tears after primary discectomy and primary laminectomy was within range of the percentages reported in the literature (1%–7.1%) and (3.1%–13%) respectively. A multicentre prospective larger study which includes all different surgical procedures performed on the lumbar spine is needed to establish a more accurate incidence rate for this common complication.