The Incidence of Durotomy and its Clinical and Economic Impact in Primary, Short-segment Lumbar Fusion: An Analysis of 17,232 Cases

Abstract

Study design: Retrospective database analysis.

Objective: To determine the incidence of durotomy in primary short-segment lumbar fusion and assess its clinical and economic impacts.

Summary of background data: The incidence of durotomy during primary lumbar fusion and its economic impact are not well described.

Methods: The Nationwide Inpatient Sample was queried for all primary 1- or 2-level lumbar fusions performed in adults for lumbar spinal stenosis between 2009 and 2011; only elective cases without concurrent diagnoses of vertebral infection, fracture, or tumor were included. χ and t-tests were used as appropriate to compare categorical and continuous variables, respectively. Multivariate regression analysis was performed to identify factors independently associated with incidental durotomy, as well as total hospital charges, costs, and length of stay.

Results: Among 17,232 cases, 802 incidental durotomies were identified (rate 4.65%). The multivariate odds of durotomy in the oldest patients (age ≥ 73) were 2.4 times greater than the odds of durotomy in the youngest patients (age ≤ 56; P < 0.0001). Durotomy was associated with increased neurological complications and longer hospital stay. Length of stay was a significant driver of cost. The multivariate odds of dural tears in teaching hospitals was significantly higher compared with nonteaching hospitals (odds ratio 1.27; 95% confidence interval, 1.06-1.52; P < 0.005). Durotomy was associated with a $10,885 increase in total hospital charges, and a $3,873 increase in estimated total costs (compared with no durotomy group with P < 0.0001).

Conclusion: Increasing age is a risk factor for durotomy in primary lumbar fusion. Durotomy is associated with neurological complications, increased length of stay, greater healthcare costs, and is more common in teaching hospitals. Length of stay is an independent driver of cost and complications.

Level of evidence: 3.