Bilateral facet arthrosis is a common source of chronic back discomfort. This condition involves arthrosis, defined as the degenerative wear and tear of a joint. Specifically, it affects the facet joints, which are small, paired stabilizing joints located in the posterior aspect of the spine. Understanding the nature of this joint degeneration is the first step toward effective management.
Understanding Facet Joints and Arthrosis
The spine is a complex column of vertebrae. Connecting each segment is a set of small joints known as facet joints (or zygapophyseal joints). These joints are situated at the back of the spinal column and are arranged in pairs, one on the left and one on the right side of each vertebral level. They function primarily to stabilize the spine, guiding movement while limiting excessive motion like rotation and hyperextension.
Each facet joint is structured like other joints in the body, featuring a smooth covering of articular cartilage that allows the bony surfaces to glide over one another. This joint is enclosed within a strong capsule and contains synovial fluid for lubrication and nourishment. Arthrosis refers to the breakdown of this protective cartilage, leading to a condition commonly known as osteoarthritis or degenerative joint disease.
When the cartilage thins and wears away, the bones begin to rub together, causing friction, inflammation, and the formation of small bony growths called osteophytes, or bone spurs. The designation “bilateral” indicates that this degenerative process is occurring symmetrically, affecting the facet joints on both the left and right sides of the same vertebral segment. The primary cause of this degeneration is chronic mechanical stress and age-related wear, often exacerbated by a loss of height in the intervertebral discs, which places increased pressure on the facet joints.
Recognizing the Common Symptoms
The pain associated with this condition is typically a chronic, dull ache localized to the lower back, particularly in the lumbar spine. Patients frequently experience stiffness, which is most noticeable in the morning or after periods of inactivity, making it difficult to stand up straight from a seated position. The pain may also extend beyond the immediate joint area, radiating into the buttocks, hip, or the back of the upper thighs.
A distinguishing characteristic of facet joint pain is its relationship to body positioning and movement. The pain generally worsens with movements that compress the joints, such as standing for long periods, walking, or bending the back backward (extension). Conversely, the pain is often relieved when sitting or bending forward, which opens the space in the facet joints. This pattern helps differentiate facet arthrosis from other spinal conditions like disc herniation, where pain might be aggravated by flexion.
The pain from arthrosis typically remains above the knee and does not present with the numbness, tingling, or weakness characteristic of true sciatica. However, in advanced cases, joint enlargement or bone spur formation can narrow the space for the nerve roots, leading to radiating symptoms.
How Doctors Confirm the Condition
The process of confirming a diagnosis begins with a detailed medical history and a physical examination, where a doctor looks for pain reproduction upon spinal extension. Imaging studies are used to visualize the extent of the degenerative changes. Standard X-rays can reveal signs of arthrosis, such as joint space narrowing and the presence of bone spurs.
Magnetic Resonance Imaging (MRI) or Computed Tomography (CT) scans offer a more detailed view of the joint and surrounding structures, allowing doctors to assess the cartilage and rule out other potential causes of back pain. However, imaging findings alone are not definitive, as many people without symptoms show signs of arthrosis on their scans.
The gold standard for confirming that the facet joint is the actual source of the pain involves a diagnostic injection procedure. A doctor will perform a medial branch block, which involves injecting a local anesthetic near the medial branch nerves that transmit pain signals from the facet joint. If the patient experiences significant, temporary pain relief—typically defined as 80% or greater improvement—it confirms that the facet joint is the pain generator.
Treatment and Management Options
Management of bilateral facet arthrosis begins with conservative approaches aimed at reducing pain and improving function. Physical therapy is a foundational component of treatment, focusing on strengthening the core muscles to stabilize the trunk and improve posture, thereby reducing mechanical stress on the joints. Therapists also instruct patients on activity modification, advising them to avoid movements that require excessive backward bending or twisting, which aggravate the joints.
Pharmacological treatments typically start with over-the-counter options such as nonsteroidal anti-inflammatory drugs (NSAIDs) to decrease inflammation and pain. If oral medications are insufficient, a physician may consider targeted interventional procedures. These include facet joint injections, which deliver a mixture of a local anesthetic and a corticosteroid directly into the joint space or around the nerve. These injections are intended to reduce inflammation inside the joint capsule and provide temporary relief.
For patients who experience positive but short-lived relief from the diagnostic nerve block, the next step is often Radiofrequency Ablation (RFA), also known as radiofrequency neurotomy. RFA is a procedure that uses heat generated by radio waves to create a lesion on the medial branch nerves, effectively disrupting the transmission of pain signals from the arthritic joint to the brain. This procedure is minimally invasive and can provide significantly longer-lasting relief, often ranging from six to twelve months or more. Surgery is considered a last resort and is rarely performed solely for arthrosis. It may be necessary if the condition has progressed to cause severe spinal instability or concurrent spinal stenosis that compresses the nerves.