Spinal Joint Injections: Purpose, Types, Procedure, and What to Expect

What is a joint injection in the spine?

A spinal joint injection involves the precise delivery of medication, typically a corticosteroid and/or an anesthetic, directly into or around the facet joints or sacroiliac joints of the spine to diagnose the source of pain and provide therapeutic relief.

Understanding Spinal Anatomy & Joint Pain

The human spine is a complex structure composed of individual bones called vertebrae, stacked one upon another. Between most vertebrae are intervertebral discs, which act as shock absorbers. Crucially, at the back of each vertebra are two small joints, known as facet joints (also called zygapophyseal joints), which connect adjacent vertebrae. These paired joints, lined with cartilage and surrounded by a joint capsule, allow for bending and twisting movements of the spine while also limiting excessive motion.

Just as with any other joint in the body, facet joints can become a source of pain due to various factors such as arthritis, injury, inflammation, or degenerative changes. Similarly, the sacroiliac (SI) joints, located where the sacrum (the triangular bone at the base of the spine) meets the ilium (part of the pelvis), are crucial for weight bearing and stability, and can also become inflamed and painful. When these spinal joints are the source of chronic back, neck, or leg pain, a joint injection may be considered.

What is a Spinal Joint Injection?

A spinal joint injection is a medical procedure designed to address pain originating from the facet joints or sacroiliac joints. It serves a dual purpose:

• Diagnostic: By injecting an anesthetic, physicians can determine if a specific joint is indeed the source of pain. If the pain is significantly reduced following the anesthetic injection, it helps confirm that the targeted joint is the pain generator.
• Therapeutic: The injection often includes a corticosteroid, a powerful anti-inflammatory medication. This aims to reduce inflammation within the joint, thereby alleviating pain and allowing for improved mobility and participation in physical therapy.

The medications are delivered directly to the affected joint, ensuring a concentrated dose at the site of inflammation or pain, which may offer more effective relief than oral medications.

Types of Spinal Joint Injections

While the general principle is similar, spinal joint injections are typically categorized by the specific joint being targeted:

• Facet Joint Injections: These target the small, paired joints located at the back of each vertebra, running from the neck (cervical spine) down to the lower back (lumbar spine). They are used to diagnose and treat pain caused by facet joint arthritis, injury, or mechanical stress. The injection may be directly into the joint space (intra-articular) or around the nerves that supply the joint (medial branch block), which are often performed for diagnostic purposes prior to a radiofrequency ablation procedure.
• Sacroiliac (SI) Joint Injections: These injections target the large, strong joints connecting the sacrum to the pelvis. SI joint dysfunction is a common cause of lower back, buttock, and sometimes leg pain. The injection aims to reduce inflammation within the SI joint and provide pain relief.

The Procedure: What to Expect

Spinal joint injections are typically performed as an outpatient procedure in a clinic, hospital, or pain management center.

• Preparation: You will discuss your medical history, current medications, and allergies with your physician. You may be asked to fast for a few hours before the procedure and arrange for someone to drive you home.
• During the Procedure:
  • You will lie in a comfortable position, often on your stomach, on an X-ray table.
  • The skin over the injection site will be thoroughly cleaned with an antiseptic solution.
  • A local anesthetic will be injected to numb the skin and underlying tissues, minimizing discomfort during the procedure.
  • The physician will use fluoroscopy (real-time X-ray guidance) or sometimes ultrasound guidance to accurately guide the needle to the precise joint. A small amount of contrast dye may be injected to confirm correct needle placement.
  • Once the needle is correctly positioned, the medication (anesthetic and/or corticosteroid) is slowly injected. You might feel some pressure or a mild burning sensation during this step.
• Post-Procedure: After the injection, the needle is removed, and a small bandage is applied. You will be monitored for a short period before being discharged. It's common to experience some temporary soreness at the injection site. Pain relief, if it occurs, may be immediate (from the anesthetic) but the full effects of the corticosteroid may take a few days to a week to manifest.

Who is a Candidate for Spinal Joint Injections?

Spinal joint injections are considered for individuals experiencing chronic back, neck, or leg pain that has not responded adequately to more conservative treatments, such as physical therapy, oral medications, and activity modification. Candidates typically include those with:

• Facet joint arthropathy or degeneration: Often leading to pain that worsens with extension or twisting movements of the spine.
• Sacroiliac joint dysfunction: Characterized by pain in the lower back, buttock, and sometimes radiating into the leg.
• Persistent pain after spinal surgery: If the pain is determined to be originating from a spinal joint.
• As a diagnostic tool: To confirm a specific joint as the source of pain before considering more invasive treatments.

Benefits and Risks

Like any medical procedure, spinal joint injections carry potential benefits and risks:

Potential Benefits:

• Pain Relief: Can significantly reduce pain, sometimes for several weeks to months.
• Improved Function: Reduced pain can allow individuals to participate more effectively in physical therapy and daily activities.
• Diagnostic Clarity: Helps pinpoint the exact source of spinal pain.
• Avoidance of Surgery: For some, injections can delay or even eliminate the need for surgical intervention.

Potential Risks:

• Common: Temporary increase in pain at the injection site, localized bruising, flushing.
• Less Common:
  • Infection: Though rare, there is a risk of infection at the injection site or within the joint.
  • Bleeding: Particularly for individuals on blood-thinning medications.
  • Nerve Damage: Very rare, but possible if the needle inadvertently contacts a nerve.
  • Allergic Reaction: To the medications or contrast dye.
  • Side Effects of Corticosteroids: Temporary elevation of blood sugar in diabetics, suppressed immune response, temporary fluid retention, or facial flushing.
• Rare Serious Complications: Though extremely rare, severe complications like paralysis or spinal cord injury are theoretical risks.

Efficacy and Long-Term Outlook

The effectiveness of spinal joint injections varies widely among individuals. Some may experience significant, long-lasting relief, while others may find only minimal or temporary benefit. It's important to understand that these injections are typically a part of a broader pain management strategy, not a standalone cure.

For optimal long-term outcomes, spinal joint injections are often integrated with other conservative treatments, particularly physical therapy. The pain relief provided by the injection can create a "window of opportunity" for patients to engage more effectively in exercises that strengthen core muscles, improve flexibility, and correct postural imbalances, addressing the underlying biomechanical issues contributing to their pain.

Important Considerations

• Not a First-Line Treatment: Spinal joint injections are generally considered after other conservative treatments have been attempted without success.
• Qualified Professional: It is crucial that these injections are performed by an experienced and qualified medical professional, such as a pain management specialist, physiatrist, or orthopedist, who uses imaging guidance for accuracy and safety.
• Realistic Expectations: Patients should have a clear understanding that the effects may be temporary and that multiple injections may be needed, although typically limited to a few per year to minimize corticosteroid side effects.
• Discuss Alternatives: Always discuss all available treatment options, including risks and benefits, with your healthcare provider.

In conclusion, spinal joint injections are a valuable tool in the comprehensive management of chronic spine-related pain. By understanding their purpose, procedure, and potential outcomes, individuals can make informed decisions in collaboration with their healthcare team.