Risk factors for surgical site infections among 1,772 patients operated on for lumbar disc herniation: a multicentre observational registry-based study

Background There are no previous studies evaluating risk factors for surgical site infections (SSIs) and the effectiveness of prophylactic antibiotic treatment (PAT), specifically for patients operated on for lumbar disc herniation. Method This observational multicentre study comprises a cohort of 1,772 consecutive patients operated on for lumbar disc herniation without laminectomy or fusion at 23 different surgical units in Norway. The patients were interviewed about SSIs according to a standardised questionnaire at 3 months' follow-up. Results Three months after surgery, 2.3% of the patients had an SSI. Only no PAT (OR = 5.3, 95% CI = 2.2-12.7, p < 0.001) and longer duration of surgery than the mean time (68 min) (OR = 2.8, 95% CI = 1.2-6.6, p = 0.02) were identified as independent risk factors for SSI. Numbers needed to have PAT to avoid one SSI was 43. Conclusions In summary, this study clearly lends support to the use of PAT in surgery for lumbar disc herniation. Senior surgeons assisting inexperienced colleagues to avoid prolonged duration of surgery could also reduce the occurrence of SSI.