The number of cervical epidural injections performed has been increasing at a rapid pace within the field of pain management. The rate of the procedure has increased 119.2% from 2000 to 2013 based on an assessment of the fee-for-service Medicare population per 100,000-an annual increase of 6.2%. Although routinely performed, the procedure carries significant risk of complication, including direct spinal cord injury, spinal cord infarction, and dural puncture.
Greater risk is thought to be secondary to midline gaps in ligamentum flavum in the cervical levels, subsequently limiting tactile perception during loss of resistance technique employed during the cervical epidural steroid injection. A recent US Food and Drug Administration investigation and Multi-Society Pain Workgroup convened to prevent neurologic complications after epidural steroid injections emphasized that cervical injections be minimized to the C7 or C6 vertebral levels given gaps in ligamentum flavum. However, performing cervical epidural steroid injections in the lower cervical regions may provide a false sense of security as cadaveric studies have shown that gaps in ligamentum flavum can range from 51-64% at these levels.
This study will assess the utility of pre-procedural MRI in evaluating gaps in ligamentum flavum in planning for cervical epidural steroid injections. We would like to quantify the probability of identifying gaps in ligamentum flavum by MRI. Our goal is to evaluate the rate of midline gaps in the ligamentum flavum in the lower cervical spine region that can be identified by MRI. We will also evaluate in subsequent analysis the prevalence of ligamentum flavum gaps in the thoracic and lumbar space.
Our hypothesis is that MRI will be able to reliably identify gaps in ligamentum flavum. Currently there are no studies characterizing the feasibility of MRI in the identification of gaps in ligamentum flavum. Additionally, there is no standard of care for identifying gaps in ligamentum flavum by Radiologists or Interventional Pain Management physicians in procedural planning for cervical intralaminar epidural steroid injections.