Osteoarthritis and sacro
However, the SI joint is unlike any other joint in the body, because it is covered by two different kinds of cartilage. The articular surfaces have both hyaline (glassy, slick) and fibrocartilage (spongy) surfaces that rub against each other. No other joints have this feature! The joint also has many large ridges and depressions (ridges are bumps and depressions are dips in the surface) that fit together like pieces in a puzzle. Although these joints are small and don’t move very much, they perform a critical role in the body. They help absorb all of the damaging shock forces of the upper body before balancing and transmitting their weight to the hips and legs. When these joints become inflamed or irritated, they may cause pain in the lower back, buttocks, abdomen, groin or legs (Unlike most other joints, the SI joint is not designed for much motion. In fact, it is common for the SI joint to become stiff and actually "lock" as we age. This might explain why manipulation and mobilization techniques have proven to be useful in physical therapy for SI joint syndrome. Mobilization is a technique where a joint is mobilized or loosened by certain exercises and stretches that the therapist can perform or teach you to perform. The SI joint usually only moves about two to four millimeters during weight bearing and forward flexion. This small amount of motion occurring in the joint is described as a "gliding" type of motion. The motion is quite different than the hinge motion of the knee or the ball and socket motion of the hip. The SI joint is a "viscoelastic joint", meaning that its major movement comes from giving or stretching. The SI joint's main function appears to be providing shock absorption for the spine through stretching in various directions. The SI joint may also provide a "self-locking" mechanism that helps you to walk. The joint locks on one side as weight is transferred from one leg to the other. Due to its small amount of movement and its complexity, finding out about the SI joint's motion is very difficult during a physical examination. This is one of the big problems in diagnosing SI joint problems. One of the most common causes of problems at the SI joint is an injury. The injury can come from a direct fall on the buttocks, a motor vehicle accident, or even a blow to the side of your pelvis. The force from these injuries can strain the ligaments around the joint. Ligaments are the tough bands of connective tissue that hold joints together. Tearing of these ligaments can lead to too much motion in the joint. The excessive motion can eventually lead to wear and tear of the joint and pain from degenerative arthritis. Injuries can also cause direct injury of the articular cartilage lining the joint. This too, over time will lead to degenerative arthritis in the joint. In some patients, pain occurs because of an abnormality of the sacrum bone itself. The sacrum bone is actually a very specialized set of vertebrae (the bones that make up the spine). Before birth, when your body is undergoing development in the womb, several vertebra fuse together to form the sacrum. However, in some people, the bones that make up the sacrum never fuse together. In these cases, two or more of the vertebra that should fuse together remain separated. This creates an odd situation where the SI joint is somewhat malformed, and a false joint occurs. This is sometimes called a "transitional syndrome". This problem can be seen on X-rays. People who have this syndrome seem to have more problems with their SI joints, as well as back pain that appears to come from that area. Women are at risk for developing SI joint problems later in life due to childbirth. During pregnancy, female hormones are released that allow the connective tissues in the body to relax. The relaxation is necessary so that during delivery, the female pelvis can stretch enough to allow birth. This stretching results in changes to the SI joints, making them "hypermobile" - extra or overly mobile. Over a period of years, these changes can eventually lead to wear-and-tear arthritis. As would be expected, the more pregnancies a woman has, the higher her chances of SI joint problems. During pregnancy, the SI joints can cause discomfort both from the effects of the hormones that loosen the joints, and from the stress of carrying a growing baby in the pelvis. Many other problems can lead to degenerative arthritis of the SI joints. It is often hard to determine exactly what caused the wear and tear to the joint. SI joint problems can also occur as a result of inflammatory arthritis. These forms of arthritis are known collectively as the spondyloarthropathies. Among this groups are condition such as ankylosing spondylitis, psoriatic arthritis, and Reiter’s disease. These conditions must be differentiated from osteoarthritis since the treatment differs greatly. SI joint problems have numerous symptoms. • Back pain - particularly low back pain The diagnosis usually begins with a history of the problem. Your doctor will want to ask you questions such as: • Have you been seriously injured? Your clinical exam may include the following orthopedic tests used to determine if the SI joint is involved. Pain during these tests is generally an indicator that the SI joint is indeed a problem. • Distraction Test - The SI joint is stressed by the examiner, attempting to pull the joint apart a bit. A CAT scan can sometimes show more detail about the joint surfaces and the surrounding bone. If the X-rays suggest something may be affecting the SI joint, your provider may recommend a CAT scan to get a better look. A bone scan can be useful in determining if the joint is inflamed. An inflamed SI joint usually shows up as a hot spot on a bone scan of the pelvis. Your doctor may also recommend that you undergo a fluoroscopic injection into the joint. During this test, a local anesthetic is injected into the joint. The doctor uses the fluoroscope to make sure the needle is actually in the joint before injecting the medication. The SI joint is located fairly deep in the upper buttock and is covered by thick muscle. It is difficult to put a needle into the joint without some guidance. A fluoroscope is a special TV camera that uses X-rays to allow the doctor to see on the screen the exact placement of the needle, making sure it is positioned accurately. Once the doctor is sure that the needle is in the right place, the anesthetic is injected to numb the joint. If the pain goes away, your provider can be relatively sure that the problem is coming from the SI joint and not somewhere else in the spine. The doctor may also add a dose of cortisone to the injection to help ease your pain. Cortisone is a powerful anti-inflammatory medication that calms the arthritis inside the joint and reduces your pain. The effect is usually temporary, but may last up to several months.
Along with steroidal medications such as Depomedrol or Kenalog, numbing medications similar to ones used in dentists’ offices are injected into the SI joints during this procedure. These injections usually take anywhere from a half an hour to an hour to complete. If your procedure is scheduled in the morning, please don’t drink any liquids or eat any solid foods after midnight. If your injection is scheduled in the afternoon, you may have water or apple juice that morning, up to two hours before the procedure. If you are taking any blood thinners such as Coumadin and Plavix, you must stop taking them a week before your injection. Let your primary care doctor and Pain Management Center physician know before you stop taking your blood thinners. Before the procedure, you will have an intravenous (IV) catheter placed in your arm or hand. This IV will provide you with fluid and medication that may make you feel a little drowsy. You will then be placed on your stomach and your back will be numbed with a local anesthetic before a small needle is inserted into the lower back near your SI joints. Once the needle is in place, the steroidal/numbing medication will be injected. When the procedure is over, the numbing medicine may make your legs feel temporarily weak. Therefore, you should limit your activity for the day of your procedure. Someone should accompany you home after the injection because you will not be able to drive. You can usually resume normal activity the day after your procedure. Once the numbing medication wears off, your pain will likely return. The steroid medication may provide longer lasting pain relief, but probably won’t begin working for 24 to 48 hours after the injection. You may experience bruising or tenderness at the injection site(s) and your pain may get worse a day or two after the injection.
If your physician feels that your back pain may be a result of SI joint syndrome, you will likely be presented with two completely different treatment options. These two options for non-surgical treatment may appear to be exact opposites - manipulation or stabilization. Why would the two treatments for one joint be so different? No one really knows what causes the pain from an SI joint that is not suffering from severe degenerative arthritis. In some cases, it appears that the joint is "too stiff" or "locked" and needs to be more mobile to function correctly. In these cases, the pain seems to respond to mobilization of the joint. In other cases, especially when there are definitely arthritis changes noticeable on X-rays, reducing the mobility of the joint may decrease the pain. Treatment is understandably varied and the results of treatment have been difficult to assess because of the complexities of the SI joint. The appropriate approach is still somewhat unclear to many providers. Both the mobilization approach and the stabilization approach to treatment involve physical therapy. Mobilization of the joint may include exercises and manipulation by the therapist. This type of therapy is directed to loosening up the joint ligaments, allowing the joint to move in a normal fashion. Stabilization of the joint may include muscle strengthening and pelvic stabilization exercises to reduce the movement in a joint that appears to be too loose. Stabilization can also be accomplished through use of a specific brace called the sacroiliac belt. The belt wraps around the hips to squeeze the SI joints together. This supports and stabilizes the pelvis and SI joints. If all conservative methods of treatment fail, surgery may become an option. Surgery on the SI joint usually consists of a fusion of the joint (also called an "arthrodesis"). Fusing the two sides of a joint together to reduce pain has been used for many years as a treatment for arthritic joints. Today, the fusion of the SI joint is not a common operation, but when necessary can reduce the pain associated with SI joint syndrome. Your surgeon will want to be absolutely sure that the pain you are experiencing is coming from the SI joint before suggesting this operation. You should discuss the procedure with your surgeon and understand what can be expected from the operation. An SI joint fusion is performed by first, making an incision over the SI joint in the lower back. The joint is opened so the surgeon can see each joint surface. Once the joint surfaces are in clear view, the articular cartilage lining the joint is removed from both surfaces. This leaves a fresh surface of bone instead of the normal cartilage. The bone surfaces are then held together until they actually heal together, or fuse. Without the articular cartilage of the joint, the body treats the two raw bone surfaces just like a fracture and tries to heal them as it normally would any broken bone. To hold the bones together, the surgeon will usually insert several metal screws across the joint. Bone graft may also be placed around the joint to help the fuse the joint. The bone graft is usually removed from the pelvic bone right beside the SI joint. Following surgery, you will probably stay in the hospital for two to four days. Once discharged, you will be given instructions by your surgeon about what to watch for and how much activity you will be allowed in the first few weeks. Your skin incision will generally heal in 10 to 14 days. The fusion of the bones usually takes 12 to 18 weeks to become strong enough to resume your normal activities. Your surgeon will take X-rays several times after the procedure to follow your healing progress and determine when the bones have fused. With any surgery, there is a risk of complications. When surgery is done near the spine and spinal cord these complications (if they occur) can be very serious. Complications could involve subsequent pain and impairment and the need for additional surgery. You should discuss the complications associated with surgery with your doctor before surgery.
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