The sacroiliac (SI) joint connects the spine and the pelvis, playing a role in weight transfer and shock absorption. Degenerative changes in this joint refer to the gradual breakdown of the cartilage and bone surfaces, a condition often termed osteoarthritis. This wear and tear can lead to discomfort and reduced function in the lower back and surrounding areas.
Understanding the Sacroiliac Joint
The sacroiliac joint is a pair of joints in the lower back, connecting the triangular sacrum bone to the ilium, the large, wing-shaped pelvic bone. These joints are relatively stiff, allowing for only a few millimeters of movement. Ligaments surround the pelvic girdle, providing stability to these joints. The SI joint’s main function involves transferring the weight of the upper body to the legs and absorbing forces generated during movement.
Causes of Degenerative Changes
Degenerative changes in the sacroiliac joint are influenced by several factors. Age-related wear and tear is a primary contributor, as the cartilage cushioning the joint surfaces can naturally diminish over time. Previous trauma, such as falls or car accidents, can directly damage the joint, initiating or accelerating the degenerative process. Repetitive stress from certain activities or occupations that involve frequent twisting, bending, or heavy lifting can also contribute to joint tissue breakdown.
Biomechanics also play a role, where imbalances like a leg length discrepancy or scoliosis can alter the alignment of the pelvis and spine, placing uneven stress on the SI joints. Prior spinal surgery, particularly lumbar fusion, may increase mechanical stress on the SI joint, as adjacent joints compensate for reduced mobility. Inflammatory conditions such as ankylosing spondylitis or psoriatic arthritis can lead to inflammation and subsequent degeneration of the SI joints.
Recognizing the Symptoms
The most common symptom of sacroiliac joint degenerative changes is pain, felt in the lower back or the back of the hips. This discomfort can radiate into the groin, hip, or thighs, and extend down the leg, often mimicking sciatica. The nature of the pain can vary, presenting as a sharp, stabbing sensation or a dull, aching discomfort.
Certain movements and activities worsen the pain associated with SI joint degeneration. Prolonged sitting or standing, climbing stairs, walking, twisting movements, and getting in and out of a car can exacerbate symptoms. Lying on the affected side can also increase discomfort. In addition to pain, individuals can experience stiffness in the lower back and tenderness when pressure is applied directly over the affected joint.
Diagnosis and Treatment Approaches
Diagnosing sacroiliac joint degenerative changes involves a combination of methods. A physical examination includes specific provocative tests, where a clinician performs maneuvers that place stress on the SI joint to elicit pain. Imaging studies like X-rays, MRI, or CT scans can show signs of degeneration, but these are not definitive in identifying the SI joint as the sole source of pain. The most reliable diagnostic tool is a diagnostic injection, where a numbing medication is precisely injected into the SI joint; if the pain significantly decreases, it indicates the joint as the pain source.
Treatment approaches for SI joint degenerative changes begin with conservative management. Non-surgical options include physical therapy, which focuses on exercises to strengthen core muscles, improve flexibility, and correct gait imbalances. Pain medications, such as non-steroidal anti-inflammatory drugs (NSAIDs) or muscle relaxants, can help manage symptoms. Bracing may offer temporary support, while therapeutic injections, including corticosteroids, platelet-rich plasma (PRP), or prolotherapy, can provide targeted pain relief and promote healing. Radiofrequency ablation is another non-surgical option that uses heat to disrupt nerve signals from the joint, reducing pain.
For individuals with severe, persistent pain that does not respond to conservative treatments, surgical intervention may be considered as a last resort. Sacroiliac joint fusion is a procedure where the bones of the joint are surgically joined together, eliminating movement and pain. Treatment plans are individualized, often involving a multidisciplinary approach.