Spinal Injections
Spinal Injections and Radiofrequency Ablation: An Overview
Spinal injections are minimally invasive, image-guided procedures used for the diagnosis and management of spinal pain. These procedures involve injecting a small volume of medication—typically a combination of a local anesthetic and a corticosteroid—near the source of pain in the spine. They are designed to provide both immediate pain relief and long-term anti-inflammatory benefits, and are a valuable part of non-surgical spine care.
How Spinal Injections Work
- Immediate Pain Relief: Local anesthetics block pain transmission by numbing the surrounding nerves, offering rapid but temporary relief.
- Long-Term Relief: Steroids help reduce inflammation in the targeted area, alleviating pain that arises from nerve irritation, disc degeneration, or arthritic changes in the joints.
Spinal injections are also useful diagnostically—by targeting specific anatomical areas and observing the pain relief obtained, clinicians can confirm the exact pain generator before proceeding with more invasive treatments.
Types of Spinal Injections
1. Epidural Steroid Injection (ESI):
In this procedure, a needle is inserted into the epidural space (the area between the dura mater and the vertebral arch). Medications are injected through a posterior approach, often under fluoroscopic guidance.
- Indications: Lumbar canal stenosis, multilevel disc disease, disc bulges/herniations.
- Notes: Cervical ESI is performed cautiously, usually avoiding local anesthetics to prevent spinal cord numbness.
2. Transforaminal Epidural Steroid Injection (TFESI):
Also known as a nerve root block, this procedure targets a specific spinal nerve root as it exits the spine via the intervertebral foramen. A lateral approach is used under fluoroscopic control for precise delivery.
- Indications: Unilateral radicular pain, lumbar disc herniation, foraminal stenosis.
- Multilevel TFESIs may be used in cases of multilevel radiculopathy.
3. Caudal Epidural Injection:
Here, the needle is introduced through the sacral hiatus at the base of the spine, allowing medications to reach the lower lumbar spine.
- Indications: L4–L5, L5–S1 disc pathologies, chronic low back pain, post-surgical scarring.
- Advantages: Easier access, especially in cases where direct lumbar ESI is technically difficult.
4. Facet Joint Injection (Facet Block):
In this technique, medication is injected either:
- Directly into the facet joint (intra-articular), or
- Around the medial branch nerves that supply the joint (medial branch block).
- Indications: Facet joint arthritis, chronic axial back or neck pain.
- Guidance: Performed under fluoroscopy or CT for precision.
5. Intradiscal Injection:
The medicine is injected into the intervertebral disc to address discogenic pain, such as pain from disc degeneration or annular tears.
- Indications: Chronic low back pain with confirmed discogenic origin.
- Technique: Performed under fluoroscopy or CT guidance.
Radiofrequency Ablation (RFA): A Complementary Technique
Radiofrequency Ablation (RFA) is a minimally invasive procedure used in conjunction with or following diagnostic injections like facet blocks or medial branch blocks. It involves the use of radiofrequency energy to generate heat and destroy small nerve fibers that carry pain signals from the spine.
- Indications: Chronic back or neck pain due to facet joint arthritis; failed facet injections with short-term relief.
- Procedure: Performed under fluoroscopy, electrodes are guided to the medial branch nerves, and controlled heat is applied.
- Duration of Relief: Pain relief can last from 6 months to 2 years.
- Advantage: Unlike steroid injections, RFA can provide longer-term relief by interrupting the pain pathways rather than just reducing inflammation.
Advantages of Spinal Injections (and RFA)
- Provide rapid and effective relief from spine-related pain.
- Allow localization of pain source, aiding in diagnosis and treatment planning.
- Offer a stepwise, non-surgical approach to managing spinal disorders.
- Help delay or avoid surgery in certain patients.
- Useful in non-specific spinal pain where imaging may not clearly show a surgical target.
RFA adds long-term relief for patients with recurrent or persistent facet-mediated pain.
Limitations and Risks
- Temporary Relief: Spinal injections do not treat the root cause. Pain may recur once the medication effect wears off.
- Steroid-Related Risks: May increase blood sugar and are contraindicated in uncontrolled diabetes.
- Bleeding Risk: Patients on blood thinners must stop them under supervision before injections to avoid bleeding around the spinal cord, which could lead to compression and neurological symptoms.
- Infection: Though rare, infection at the injection site is a potential risk.
- RFA Consideration: RFA can sometimes cause localized soreness and requires accurate diagnosis to be effective.
Conclusion
Spinal injections and radiofrequency ablation form an integral part of the conservative management of spinal disorders. They are safe, effective, and minimally invasive tools that provide both diagnostic clarity and symptomatic relief. When used appropriately and in the right clinical context, they can significantly improve quality of life and may help postpone or avoid spine surgery altogether.
Frequently Asked Questions (FAQs)
Spinal injections are used to treat back and leg pain caused by various spinal conditions. Common types include:
- Epidural Steroid Injections (ESI): Reduce inflammation around spinal nerves, commonly used for sciatica and disc herniation.
- Facet Joint Injections: Target small joints between vertebrae that may be arthritic.
- Medial Branch Blocks: Numb the nerves supplying the facet joints; used for diagnosis and treatment.
- Sacroiliac (SI) Joint Injections: Address pain in the pelvic area and lower back.
- Nerve Root Blocks / Selective Nerve Root Injections: Focused injections at specific nerve roots.
- Caudal Epidural Injections: Delivered at the base of the spine, suitable for diffuse lower back pain.
- Trigger Point Injections: For muscular pain that refers to the back or legs.
These injections are often image-guided (with fluoroscopy or ultrasound) for accuracy.
- Herniated disc: Transforaminal epidural steroid injection or interlaminar ESI.
- Sciatica: Epidural steroid injection or nerve root block.
- Cervical spine issues: Cervical epidural steroid injections or facet joint injections in the neck region.
- L4-L5 or L5 nerve compression: L4-L5 or L5-S1 epidural steroid injection is commonly used.
Most spinal injections are mildly uncomfortable rather than painful. A local anesthetic is used to numb the area. You may feel pressure or a warm sensation when the medication is injected. Post-procedure soreness is common but temporary. For anxious patients, sedation is sometimes offered.
Pain relief from spinal injections can last from a few weeks to several months. The duration depends on:
- The condition being treated
- The type of injection
- The patient’s activity level and adherence to rehab
Some patients require repeat injections or transition to surgery if conservative treatment fails.
When performed by trained specialists using imaging guidance, spinal injections are generally safe. However, like all procedures, they carry some risks:
- Infection
- Bleeding or hematoma
- Allergic reaction to medications
- Dural puncture leading to spinal headaches
- Rarely, nerve injury or paralysis
Precautions like sterile technique, patient screening, and imaging significantly reduce these risks.
Most doctors recommend no more than 3–4 injections per year, especially for steroid-based procedures. Repeated injections over time may lead to:
- Bone thinning (osteoporosis)
- Weakened muscles or tissues
- Hormonal side effects
- Dependency on injections without addressing the root cause
They are best used as part of a broader pain management strategy that includes physical therapy.
Spinal injections can offer effective short- to medium-term relief, especially for nerve-related pain. They're often used to:
- Delay or avoid surgery
- Diagnose the exact pain source
- Reduce inflammation to allow physical therapy
They’re considered worthwhile for many patients, especially when used judiciously.
