Microscopic Study of Injectable Steroids: Effects of Postmixing Time on Particle Aggregation

Background: Epidural steroid injection (ESI) is a common practice for pain treatment since 1953. In 2014, the FDA issued a warning about ESI. Studies have focused on the effect of the particle size and their ability to generate harmful aggregates. Although steroid aggregates provide longer times for reabsorption, therefore a longer anti-inflammatory effect, they are potentially harmful to the central nervous system via embolic mechanisms. Previous studies have established that steroidal aggregates with asizes over 100 μm are potentially able to occlude blood vessels. Studies by Tiso et al and Benzon et al addressed the role of steroids on CNS adverse events, with similar outcomes. The main …