Spinal injections are pain relieving procedures. A small mixture of steroid and local anesthetic is injected near painful pathology. Spinal injections immediately reduce pain by local anesthetic effect. Long term pain relief is provided by reduced inflammation caused by steroids.
Spinal injection can be of various types based on site and target pathology.
- Epidural Steroid Injection (ESI): A needle is inserted in the epidural space (area between dura and inner surface of vertebral arch) from a posterior approach. A mixture of varying doses of local anesthetic and steroid is injected in this space. This procedure is suited for patients with spinal canal stenosis and multilevel lumbar pathologies. Lumbar ESI is a very familiar approach as it is the approach commonly used to anesthetize lower limbs for various surgeries. Local anesthetic is avoided for Cervical ESI to reduce any chance of temporary numbness in cervical spinal cord.
- Trans-Foraminal Epidural Steroid Injection (TFESI): A lateral approach is used to inject medicines in vertebral foramen. This procedure is done under fluoroscopy guidance to direct needle to correct level and site. TFESI is also called Root Block as it target a single root in the foramen. Multiple TFESI can be given for multilevel root compression. Primarily used for lumbar nerve roots, TFESI can also be given for cervical and thoracic nerves.
- Caudal Epidural Injection: This procedure is similar to epidural injection; however, site of entry for medicines is from sacral bone. This procedure is best suited for lower lumbar spine pathologies (L4-5, L5-S1).
- Facet Block: Mixture of local anesthetic and steroid is injected inside the arthritic facet joint or the nerve supplying the facet joint is anesthetized. This procedure is done under fluoroscopy guidance. Facet block is done for both lumbar and cervical spine.
- Intra-Discal Injection: Medicine mixture is injected inside the disc material under fluoroscopy guidance. This lead to reduction in pain of disc origin (disc degeneration, annular tear etc.). This procedure is primarily used in lumbar disc degeneration.
Advantages of Spinal Injections:
- Spinal injections give immediate relief to patient’s symptoms.
- Spinal injections give long term relief due to anti-inflammatory effects of steroids.
- Spinal injections provide stepwise approach to patients suffering from spinal pathologies before deciding about the surgery.
- They help in confirming the diagnosis by assessing pain relief received after injection at the site of suspected pathology.
- Spinal injections help in postponing the surgery by providing required pain relief.
- They are helpful in providing symptomatic relief to patients where spinal pathology is either not obvious or not severe enough to require surgery.
Side Effects/ Limitations of Spinal Injections:
- They do not cure primary pathology. Pain might return after the effect of medicines is over.
- Steroids are contraindicated in patients with uncontrolled diabetes as they can cause infection at the site of injection and can increase blood sugar.
- Spinal Injections a (especially ESI) are contraindicated in patients on blood thinners. Injection needle can puncture small veins around the spinal cord and cause bleeding in the spinal canal. This can compress spinal cord and cause symptoms of spinal stenosis, which might require surgery.
In essence, spinal injections provide good symptomatic relief to the patient. They are a good diagnostic tool and are commonly used as a stepwise treatment for spine pathologies.