Physical Medicine and Rehabilitation

Sacroiliac Joint Dysfunction (SI Joint Pain)

Anatomy

The spinal column is made up of small bones (vertebrae) stacked on top of one another, creating the natural curves of the back. Between the vertebrae are flat, round, rubbery pads (intervertebral disks) that act as shock absorbers and allow the back to flex or bend. Muscles and ligaments connecting the vertebrae allow motion while providing support and stability for the spine and upper body. Each vertebra has an opening (foramen) in the center and these line up to form the spinal canal. Protected by the vertebrae, the spinal cord and other nerve roots travel through the spinal canal. Nerves branch out from the spinal column through vertebral openings, carrying messages between the brain and muscles. Facet joints align at the back of the spinal column, linking the vertebrae together and allowing for rotation and movement. Like all joints, cartilage covers the surface where facet joints meet.

The spine contains three segments: lumbar, thoracic and cervical. The lumbar spine consists of five vertebrae (L1-L5) located in the lower back; these are the largest unfused vertebrae in the spinal column, enabling them to carry more of the body's weight. Disks in the lumbar spine are composed of a thick outer ring of cartilage (annulus) and an inner gel-like substance (nucleus). Built for power and flexibility, the lumbar spine supports the entire torso and allows movement such as lifting, twisting and bending. The two lowest segments (including vertebrae and discs) bear the most weight, making them the most susceptible to injury and degradation.

At the bottom of the spine, between the lumbar spine (L5) and the tailbone (coccyx), is a triangular-shaped bone (sacrum) consisting of five segments (S1-S5) that are fused together. The sacrum is connected to the hips, or pelvis (iliac crest), by the sacroiliac joints, which are located on each side of the lower spine. The sacroiliac joints act as shock absorbers, transmitting all the forces of the upper body to the hips and legs. Reinforced by strong, surrounding ligaments, these small joints are very strong and stable, but they do not allow much motion.

Description

Sacroiliac joint dysfunction (SI joint pain) is a painful condition resulting from improper or abnormal movement of the sacroiliac joints. Generally more common in young and middle-aged women, sacroiliac joint dysfunction can cause inflammation of the joints (sacroiliitis), as well as pain that occurs in the lower back, buttocks or legs. Pain can also spread to surrounding muscles, which may spasm in response to the joint dysfunction.

Symptoms

When SI joint pain is the result of too much movement of the joint (hypermobility or instability), pain is typically experienced in the lower back and/or hip, but may also radiate into the groin area. When caused by too little movement of the joint (hypomobility or fixation), the pain usually occurs on one side of the lower back or buttocks, and may radiate down the leg. Although painful symptoms usually remain above the knee, leg pain can be particularly difficult and may extend to the ankle or foot. SI joint pain may feel similar to that of sciatica or a lumbar disc herniation.

Cause

SI joint pain is the result of improper movement of the sacroiliac joints, either too much or too little. When the ligaments supporting the sacroiliac joints become loose due to injury, pregnancy or other causes, they may allow too much motion in the joint. Cases of too little movement are often the result of degenerative joint diseases, such as arthritis, that force sacroiliac joints to overcompensate for problems in other nearby joints.

Diagnosis

After reviewing your medical history, your physician will ask you to describe how your pain started, where it occurs, and exactly how it feels. Diagnosing sacroiliac joint dysfunction can be difficult because symptoms are often so similar to those of other conditions, such as disc herniation and radiculopathy (pain along the sciatic nerve that radiates down the leg), so it is important to discuss all of your symptoms with your physician. An anesthetic injection block may be applied to the SI joint to assist in diagnosis and provide relief from pain. X-rays and additional imaging studies, such as a magnetic resonance images (MRI), may be recommended to fully assess and diagnose your condition, and to rule out other potential causes for your symptoms.

During a physical examination, your orthopaedic surgeon may use movement of the joint to eliminate other causes and locate the source of your pain. If the motion recreates the symptoms and no other explanation can be found, the sacroiliac joint may be the cause.

Nonsurgical Treatment

Treatment for sacroiliac joint dysfunction is typically conservative, or nonsurgical, and focused on restoring normal joint motion. Typical treatments for SI joint pain include:

• Ice, heat and rest—Initially, your physician may recommend rest to lessen the irritation, combined with the application of ice or cold packs, as needed, to reduce inflammation. To do this properly, apply crushed ice directly to the painful area, but over a thin cloth. Ice should not be applied directly to the skin and should be applied for no more than 15 to 20 minutes at a time, waiting at least one hour between icing sessions. Chemical cold products ("blue" ice) should not be placed directly on the skin and are not as effective. Depending on the duration of sharp, intense pain, the application of ice can be continued for 2 days, up to 2 weeks. Once inflammation has been reduced, a gradual return to normal activities may be advised. During the healing process, the application of heat (such as a heat wrap or hot bath) may be helpful, however, it should not be used during acute, high-intensity pain.
• Nonsteroidal medications—The first line of treatment often includes pain medications, such as acetaminophen, or anti-inflammatory drugs like ibuprofen or naproxen (NSAIDs) to help relieve pain and inflammation as well as swelling, which contributes to pain. Most people are familiar with nonprescription NSAIDs such as aspirin and ibuprofen, however, whether using over-the-counter or prescription strength, they must be taken carefully. Using these medications for more than one month should be reviewed with your primary care physician. If you develop acid reflux or stomach pains while taking an anti-inflammatory, be sure to talk to your doctor.
• Chiropractic manipulations—Manual manipulation provided by a chiropractor, osteopathic doctor, or other qualified health practitioner may help. Although this treatment can be highly effective when the SI joint is fixated, or "stuck," it can be irritating if the SI joint is hypermobile. Potential methods include: side-posture manipulation, drop technique, blocking techniques, and instrument-guided methods. Discuss chiropractic manipulations with your orthopaedic surgeon to determine the most appropriate method for you.
• Supports or braces—If the SI joint is hypermobile, or too loose, a brace (orthotic) similar to a wide belt can be wrapped around the waist and pulled snugly to stabilize the area. This can be especially helpful when the joint is inflamed or painful, then as discomfort lessens the brace can be weaned away.
• Physical therapy and exercise—Controlled, gradual physical therapy may help to strengthen the muscles around the sacroiliac joint and increase range of motion. Gentle, low-impact aerobic exercise can also aid in increasing the flow of blood to the area, which stimulates healing. For severe pain, water therapy may be used to provide buoyancy for the body and reduce stress on the painful joint. A spine conditioning program or low back exercises may also be recommended.
• Sacroiliac joint injections—Primarily used for diagnostic purposes to determine if the sacroiliac joint is the cause of the pain, these injections can also provide immediate pain relief. Typically, the injection is comprised of an anesthetic (such as lidocaine or bupivacaine, or novocaine) and an anti-inflammatory medication (often a corticosteroid) to help reduce inflammation around the joint, which in turn helps alleviate symptoms. Immediate pain relief can allow the patient to begin a physical therapy program and return to normal activity levels.

Surgery

In severe cases where pain has not been addressed after several weeks or months of one or more nonsurgical treatments, sacroiliac joint fusion may be an option. During this procedure, one or both of the sacroiliac joints are fused with the goal of eliminating any abnormal motion.

As with any surgery, there are some risks, and these vary from person to person. Complications are typically minor, treatable and unlikely to affect your final outcome. For most people, surgery can provide relief of symptoms and return to function with relatively low risk of complications. Overall, elderly patients have higher rates of complications from surgery, as do patients who are overweight, diabetics, smokers, or suffering from multiple medical problems. Among the general, potential risks associated with surgery are infection, bleeding and blood clots, and reactions to anesthesia. Be sure to discuss the potential risks and benefits with your surgeon prior to surgery.