Spinal arthritis, also known as spondylosis, describes a condition where the joints within the spine become inflamed and degenerate. This inflammation primarily affects the facet joints, which are small joints located at the back of the spine that enable movement and provide stability. When the protective cartilage in these joints wears down, it causes pain and stiffness. Arthritis in the spine can occur anywhere from the neck (cervical spine) down to the lower back (lumbar spine).
The Primary Forms Affecting the Spine
Arthritis in the spine is broadly categorized into two main groups based on the underlying cause: degenerative and inflammatory. Degenerative arthritis, or osteoarthritis, is the most common form, arising from mechanical stress and age-related wear and tear. This type primarily affects the facet joints, leading to cartilage breakdown and the formation of bone spurs (bony overgrowths). The lower back and neck are the most frequent locations for this degenerative process due to heavy weight-bearing and high mobility.
The second category is inflammatory arthritis, driven by an autoimmune response where the body mistakenly attacks its own healthy joint tissues. Conditions like Ankylosing Spondylitis (AS) and Psoriatic Arthritis fall into this group, causing inflammation in the joints and where ligaments and tendons attach to the bone. AS typically targets the sacroiliac joints at the base of the spine. Over time, severe inflammation can lead to the vertebrae fusing together, a process called ankylosis, which restricts spinal movement.
How Spinal Arthritis Manifests
Persistent pain and stiffness in the back or neck are primary symptoms of spinal arthritis. This discomfort often presents as a dull, chronic ache localized to the affected spinal segment. Pain from degenerative arthritis tends to worsen with activity or prolonged periods of sitting and twisting movements, as these actions increase friction on the worn joint surfaces.
Stiffness is particularly pronounced in the morning or after periods of rest, making it difficult to straighten the back or turn the head. This morning stiffness, especially in inflammatory types, may improve slightly with movement as the day progresses. The loss of flexibility restricts the spine’s range of motion, making simple tasks like bending down or looking over the shoulder challenging.
As the condition advances, bone spurs and inflammation can narrow the space around the spinal nerves, leading to referred pain in the limbs. If nerve roots are compressed in the lower back, sciatica may occur, characterized by sharp, shooting pain, tingling, or numbness that travels down the leg. Nerve compression in the neck can cause radiculopathy, leading to pain and weakness extending into the arms and hands. In severe, long-standing cases, the body’s attempt to stabilize the spine can lead to postural changes, such as stooping or forward hunching of the upper back.
Diagnostic Methods
Diagnosing spinal arthritis begins with a thorough physical examination and medical history review to understand the pattern and location of symptoms. The physician assesses the spine’s range of motion, checks for tenderness, and performs neurological tests to evaluate muscle strength, reflexes, and sensation. This initial assessment guides the selection of specialized diagnostic tools.
Imaging studies visualize damage within the spine and confirm the diagnosis. X-rays are usually the first step, effectively showing bony changes such as joint space narrowing (indicating cartilage loss) and the presence of bone spurs. For a detailed look at soft tissues like the intervertebral discs, spinal cord, and nerve roots, a Magnetic Resonance Imaging (MRI) scan is used. A Computed Tomography (CT) scan provides cross-sectional images useful for evaluating bony structures and the extent of any nerve canal narrowing.
Laboratory tests are employed to help differentiate between degenerative and inflammatory forms of arthritis. These tests check for markers of systemic inflammation, such as the C-reactive protein (CRP) or the erythrocyte sedimentation rate (ESR). For suspected inflammatory conditions like Ankylosing Spondylitis, genetic testing may be performed to check for the presence of the HLA-B27 gene variant, though this is not a definitive test.