What is a Spine Injection?

A spine or spinal injection is a minimally invasive procedure in which a medication is administered, using a needle and syringe, into the spine under real-time X-ray guidance - called fluoroscopy - to diagnose and treat numerous spine conditions.

Anatomy of the Spine

The spine is made up of several small bony segments called vertebrae. These vertebrae are categorized into cervical or neck vertebrae, thoracic (upper back), and lumbar (lower back). Cushioning discs that are present between each vertebra act as shock absorbers. A thin, flexible, cylindrical bundle of nerve fibers called the spinal cord passes through the entire vertebral column and branches out to the various parts of our body. Any damage or deformity to the bones of the vertebral column, or to the discs present between the vertebrae, can damage these nerves, leading to pain in the body part that the nerve supplies.

Indications for Spine Injections

Your physician may recommend spine injections when your neck or back problem is severe enough that it does not respond to conservative measures. Spine injections are utilized in two ways:

• As a treatment to relieve pain (therapeutic)
• To diagnose the source of neck, back, arm, or leg pain (diagnostic)

Most spine injections are employed to relieve neck or back pain when non-surgical treatments such as medications and physical therapy have proven unsuccessful.

Types of Spine Injections

Types of spine injections used to manage painful ailments of spinal origin include:

• Epidural spine injections: Epidural spine injections are administered into the epidural space of the spine. The epidural space is the space between the outermost covering of the spinal cord (dura mater) and the wall of the spinal canal. It is approximately 5mm wide and is filled with spinal nerve roots, fat, and small blood vessels. Epidural spine injections are recommended for spine degenerative conditions such as herniated discs, spinal stenosis, and many other conditions that may induce back pain due to the compression of the associated spinal nerves.
• Facet joint injections: Facet joint injections are administered into inflamed and painful facet joints. These are the joints connecting adjacent vertebrae. Each vertebra has four facet joints: one pair connects to the vertebra above, and the second pair connects to the vertebra below. Thus, they are present on both sides of the spine from the neck to the lower back, providing flexibility and smooth movement to both the neck and the spine. Facet joint injections are given to relieve pain in the back, neck, arm, and leg, and even to relieve headaches caused by inflammation of the facet joints.
• Sacroiliac joint injections: Sacroiliac joints (SI joints) are joints in the lower back region, where the sacrum and ilium bones meet. Any inflammation or irritation in SI joints may cause pain in the lower back, abdomen, groin, buttocks, or legs. Sacroiliac joint injections can be used either for diagnostic or therapeutic purposes (for pain). As a diagnostic tool, it helps your doctor locate the origin of pain. For therapeutic uses, SI joint injections will deliver a steroid medication along with an anesthetic agent to provide pain relief.
• Medial branch nerve blocks: Medial branch nerves are small nerves that supply the facet joints of the spine. A medial branch nerve block is an injection of a local anesthetic administered near the medial branch nerves to temporarily block the pain signal carried from the facet joints of the spine to the brain. It assists your doctor in diagnosing the cause of your back pain. If a medial branch block is successful in confirming that the pain is originating from the facet joints, radiofrequency ablation is suggested to provide longer pain relief.
• Radiofrequency ablation: Radiofrequency ablation (RFA), also called rhizotomy or neurotomy, is a novel non-surgical technique to treat pain. This technique employs radiofrequency (RF) waves to produce heat in order to damage the nerves transmitting pain signals to the brain. This procedure is performed to treat painful facet joints in the spine that usually cause chronic lower back pain and neck pain.
• Regenerative therapy injections: Regenerative injections utilize potent growth factors from your own body such as bone marrow concentrate and platelet-rich plasma to trigger, accelerate, and support the natural healing process. When harvested, concentrated, and injected into an injured/painful region, these crucial growth factors can mitigate pain and restore function by repairing damage on a cellular level.
• Sympathetic nerve blocks: Sympathetic nerves originate from the front of the spine and are part of the autonomous nervous system that controls several involuntary body functions, including blood pressure, heart rate, digestion, and sweating. Sometimes the nerves can continue to transmit pain even after an injury is healed. A sympathetic nerve block is an injection of an anesthetic near the affected sympathetic nerves to block pain. Its purpose is to determine if damage to the sympathetic nerves is the cause of the patient’s pain.  If the block provides temporary pain relief, your physician may recommend a series of blocks to provide longer pain relief.

Preparation for Spine Injections

In general, pre-procedure preparation for spine injections may involve the following:

• A review of your medical history and routine lab tests such as blood work.
• You will be asked if you have allergies to any medications, anesthesia, contrast dye, or latex.
• You should inform your doctor of your current medication list or other supplements you are taking, or any conditions you have such as an infection or blood disorder.
• You will be asked to avoid certain medications, as the procedure cannot be performed on patients taking blood thinners, or who have an active infection.
• You should arrange for someone to drive you home after the procedure.
• A signed informed consent form will be obtained from you after the pros and cons of the procedure have been explained.

Procedure for Spine Injections

Usually, spinal injections are performed on an outpatient basis, meaning you will be discharged home the same day as the procedure. The procedure involves the following steps:

• You will be taken to the procedure room and asked to lie in a prone position (face down) on the procedure table.
• The area of the spine where the needle is to be inserted is cleaned with an antiseptic solution and numbed with a local anesthetic injection so that you do not feel pain during the procedure. 
• A thin, hollow needle is then inserted into the affected spine area under fluoroscopic (live X-ray) guidance to ensure accurate needle placement. This system gives real-time X-ray images of the position of the needle in the spine on a monitor for the surgeon to view.
• A contrast material is then injected to confirm that the drug reaches the affected nerve.
• When the doctor is satisfied with the position of the needle, the anesthetic drug and corticosteroid are injected through the same needle inserted in the spine.
• The steroid medication is injected into the inflamed joint, reducing the inflammation and relieving the pain.
• Finally, the needle is removed, and the injection site is covered with a dry, sterile bandage.
• Patients may feel some pressure during the injection, but mostly the procedure is painless and takes about 15-30 minutes to complete.

Post-Procedure Recovery and Care

After the procedure, you should not drive or operate machinery for the next 12 hours, as the procedure can cause drowsiness, temporary numbness, weakness, and soreness. You will spend some time in the recovery area and will then be discharged home once you are deemed stable. You may experience localized pain at the injection site for a few days after the procedure which can be managed by the application of ice packs. Once the injected medications start taking effect, you should experience a significant reduction in pain and inflammation, enabling you to return to your daily activities. In cases where improvement in the pain is noted, patients are advised to perform moderate activities with regular exercises.

Risks and complications

Although spinal injections are normally safe, some risks and complications may occur, such as:

• Allergic reaction
• Bleeding from the site of injection
• Infection at the site of injection
• Pain or discomfort at the site of injection
• Nerve or spinal cord injury
• Bladder dysfunction
• Fluid retention (edema)
• Headache
• Nausea
• Paralysis (very rare)