What are the sacroiliac joints?
The sacroiliac joints, also known as the "SI joint" are the two joints on each side of the pelvis that are formed where the sacrum and each one of the iliac bones meets. The sacrum is often called the "tailbone" and the iliac bones are commonly referred to as the "hip bones". However, the portion of the pelvic bones involved with the sacroiliac joints are not part of the actual hip joint. The general term for the pelvic bones is the "innominate bone". Each one of the innominate bones is actually made up three bones that fuse together as a normal part of human development. The ilium is the bone that your belt sits on and is often commonly called the "hip bone". The ilium is the part of the pelvis you sit on. The pubic bone is the lower front portion of the pelvis above and on either side of the genitalia. The sacrum is triangular in shape and is located in the middle line of the lower back below the last lumbar vertebra. Anatomically, the sacrum can be viewed as a modified lumbar vertebra where the spinal canal ends and the last five spinal nerves exit from the spine. The SI joints function to link the spine to the pelvis. This linkage allows forces, weight, and stress to be transferred between the upper body, pelvis, and legs.
What type of joint is the sacroiliac joint?
The sacroiliac joints are what is known as diarthrodial joints. Diarthrodial joints are joints that have a joint capsule and are lined with hyaline cartilage, have a synovial membrane, and contain synovial fluid to lubricate the joint. The SI joints are made up of the sacrum and the two innominate bones of the pelvis. Each innominate is formed by the fusion of the three bones of the pelvis. These three bones are the ilium, ischium, and pubic bone.
What are symptoms of SI joint pain?
The presenting symptoms of sacroiliac joint pain can be quite varied. Usually, the pain is below the L5 level in the lumbar spine. Pain is often felt in the pelvis, buttocks, hip, or groin. Sometimes there is a feeling of instability or "giving away" of the low back an area around the sacroiliac joint. Other times the pain can present with more of a neuropathic characteristic with symptoms such as pain, tingling, numbness, and even weakness. These neuropathic symptoms, particularly weakness, should be evaluated by a physician as soon as possible to make sure that the problem is not a herniated disc or other condition that may be causing permanent nerve damage.
People with sacroiliac joint pain also often have trouble sleeping due to the pain. They find themselves having to toss and turn frequently during the night to find a position of comfort. Additionally, prolonged sitting or prolonged standing is difficult for those suffering from SI joint pain. Usually, however, walking helps improve comfort.
What does it feel like when your SI joint is "out"?
The pain felt from inflamed or unstable sacroiliac joints can vary from person-to-person. The pain may only be on one side (unilateral) or it may be on both sides (bilateral). Generally, the pain pattern from sacroiliac joints is axial, staying between the beltline and the knee. It generally is in the lower back, buttocks, groin, and/or thigh. In a significant percentage of cases, however, the pain can extend all the way down to the foot causing sacroiliac joint pain to be confused with pain from a herniated disc.
How do I get my SI joint back in place?
Often, home exercise and stretching can be used to treat sacroiliac joint pain. Prior to resorting to surgical treatment, physical therapy or chiropractic care is usually tried in an effort to correct the problem in a simple of a fashion as possible. The physical therapist or chiropractor can teach you to exercise and stretching techniques to balance the muscles around the SI joint and realign the joint if it is symptomatic. Many patients are able to use these techniques either daily or intermittently as needed to treat their sacroiliac joint.
What causes inflammation of the sacroiliac joints?
Inflammation of the sacroiliac joints is known as sacroiliitis. This can involve one or both of the SI joints. Sacroiliitis is a general term. The specific cause of sacroiliitis can be from a number of possibilities. The most common cause of sacroiliitis is general wear and tear of the joint over time. This is degenerative arthritis also known as osteoarthritis. There is some evidence that the degree of osteoarthritis a person experiences may have a genetic component. However, other factors such as trauma, a long-term heavy strain on the spine, and obesity may accelerate the rate of degenerative arthritis. Another cause of sacroiliitis includes inflammatory conditions such as ankylosing spondylitis or rheumatoid arthritis.
What is in a sacroiliac joint injection?
A diagnostic SI joint injection is used to evaluate and confirm a suspected diagnosis of sacroiliitis/SI joint pain. This is done by anesthetizing (numbing) the sacroiliac joint with local anesthetics such as lidocaine or bupivacaine. The injection is performed under fluoroscopy (X-ray guidance) for accuracy.
A sacroiliac joint injection is a precision injection performed under fluoroscopic guidance in order to diagnose and/or treat sacroiliac joint pain. A special type of x-ray known as a fluoroscope is used to guide a needle into the joint, inject contrast (dye) for confirmation of needle placement, and then inject local anesthetic and/or anti-inflammatory corticosteroid. Sometimes ultrasound guidance is used instead of x-rays but the x-ray guidance has been shown to be superior in accuracy.
When a sacroiliac joint injection is used for diagnostic purposes, the amount of relief obtained after the injection of local anesthetic is evaluated postoperatively. Opinions vary regarding what degree of relief constitutes a positive result. Some research advocates relief percentages as low as 50% while the other studies support relief percentages as high as 80 to 100% be used to determine if the pain is actually coming from a sacroiliac joint.
What is minimally invasive sacroiliac joint fusion?
Minimally invasive sacroiliac joint fusion is a relatively new method of stabilizing the SI joints surgically while using much smaller incisions and instruments than in previous techniques. These minimally invasive techniques can be used to treat pain and dysfunction resulting from traumatic disruption of the sacroiliac joints or degenerative sacroiliitis.
What is the recovery time for SI joint fusion?
Recovery from a sacroiliac joint fusion usually takes between two and four weeks. If a fusion is required on only one side instead of two, the recovery process is generally quicker than if both sides require fusion. Patients who have had previous spinal surgery may take longer to heal. Other medical conditions such as diabetes or osteoporosis may slow healing. Additionally, behavioral choices such as smoking can dramatically lengthen the time required for bones to heal. In fact, in other spinal surgeries such as intervertebral fusion, the rate of failed fusion known as "nonunion" can be as much as 10 times higher in smokers than non-smokers.
Si Joint Fusion Success Rate
A recent study evaluated the success rate of minimally invasive sacroiliac joint fusion compared with nonsurgical treatment including other minimally invasive options such as injections and radiofrequency of the nerves on the back of the joints. In this study, it was found that using a 50% reduction as the threshold for diagnosing pain from the SI joint gave equal long-term results in pain relief and functional improvement as using a higher percentage thresholds such as 75%. The authors concluded that using the higher percentage as a diagnostic threshold would not improve the overall outcomes of the minimally invasive fusions but could deny an effective treatment to many individuals who may have gotten substantial long-term relief from the treatment.
In this study, minimally invasive sacroiliac joint fusion reduced pain by 50% or more in 77 to 85% of the subjects treated. Additionally, functional disability was improved and 59.4% to 75% of the subjects treated. As previously stated, the degree of improvement after the surgery was not related to whether a 50% improvement or a 75% improvement diagnostic threshold was used.
What to expect after SI joint fusion
Most patients undergoing minimally invasive sacroiliac joint fusion will remain in the hospital 1 to 2 days. Icepacks and short-term pain medication may be required in the postoperative period. Depending on the job the individual has, most people can be back to work within six weeks. Continued improvement may occur for six months to a year after the surgery.
Reelated Conditions/ Search Terms: Arthritis, Lower Back Pain, Sciatic Nerve, Sciatica Nerves, Spinal Stenosis, Knee Pains, Herniated Disk, Degenerative , Pinched Nerve, Sacroiliac Joint, Pain Management