Durotomy is associated with pseudoarthrosis following lumbar fusion

Pseudoarthrosis is a known complication following lumbar fusion, and although several risk factors have been established, the association of durotomy and pseudoarthrosis has not been studied to our knowledge. A retrospective review was performed to identify all adult patients who underwent lumbar posterolateral fusion (without interbody fusion) for degenerative spine disease over a 20 year period at a single institution. Patients were divided into durotomy and no durotomy cohorts. Patients were included if they had at least 1 year of follow-up. The main outcome variable was development of pseudoarthrosis. A total of 327 patients were identified, of whom 17 (5.19%) had a durotomy. Pseudoarthrosis rates were significantly higher in the durotomy group (35.29%) when compared to the no durotomy group (13.87%), with the difference being statistically significant (p = 0.016). Univariate analysis revealed that durotomy (p = 0.003) and the number of levels fused (p = 0.015) were the only two significant risk factors for pseudoarthrosis. After controlling for the number of levels fused, the adjusted relative risk (RR) revealed that patients with a durotomy were 2.23 times more likely to develop pseudoarthrosis (RR 2.23; 95% confidence interval 1.05-4.75) when compared to patients without durotomy. The findings in the present study suggest an association between durotomy and pseudoarthrosis development. Patients with a durotomy were 2.2 times more likely to develop pseudoarthrosis compared to patients without a durotomy. Future and larger studies are required to corroborate our findings.