What is Sacroiliac Joint pain?
Dysfunction in the sacroiliac joint, also called the SI joint, can sometimes cause lower back and/or leg pain. Leg pain from sacroiliac joint dysfunction can be particularly difficult to differentiate from radiating leg pain caused by a lumbar disc herniation (sciatica) as they can feel quite similar. Today it is estimated that the sacroiliac joint is responsible for 15% to 30% of lower back pain cases.
What is the Sacroiliac Joint?
The sacroiliac joint connects the hip bones (iliac crests) to the sacrum, the triangular bone between the lumbar spine and the tailbone (coccyx). The primary function of the sacroiliac joints is to absorb shock between the upper body and the pelvis and legs.
The sacroiliac joint typically has little motion. Small movements at the joint help with shock absorption and forward/backward bending. The joint is reinforced by strong ligaments surrounding it, some of which extend across the joint in the back of the pelvis. This network of soft tissues provides support, limits movement at the joint, and assists with absorbing pressure.
What can cause Sacroiliac Joint pain?
The primary causes of SI joint dysfunction include:
- Too much movement in the sacroiliac joint can cause the pelvis to feel unstable and lead to Pain from too much motion is typically felt in the lower back and/or hip, and may radiate into the groin area.
- Too little movement can cause muscle tension, pain, and may inhibit Pain is typically felt on one side of the low back or buttocks, and can radiate down the back of leg (similar to sciatica).
Certain factors can raise the risk of developing sacroiliac dysfunction and pain, including:
- Gait issues, such as leg length discrepancy or scoliosis, which can place uneven pressure on one side of the pelvis, causing wear-and-tear on the SI joint and an increased risk of
- Pregnancy or recent childbirth can commonly cause sacroiliac joint pain in women due to weight gain, hormonal changes causing ligaments in the SI joint to relax (hypermobility), and pelvic changes associated with childbirth. For some women, ligaments may remain loose after childbirth and cause sacroiliac joint pain and instability to
- Prior lower back surgery, which can displace pressure to the sacroiliac One study found that sacroiliac joint pain tends to be more common following a fusion surgery than a discectomy.1 The same study found that multi-level surgery was more likely to cause sacroiliac joint pain than a single-level procedure. Sacroiliac joint pain has also been reported following hip joint replacement surgery and bone grafts taken from the iliac bone (the “wings” of the pelvis).
- Activities that place repeated stress on the joint, such as contact sports, regular heavy lifting, or labor-intensive jobs. If pelvic and/or low back muscles are unconditioned, stress from prolonged sitting or standing may also contribute to SI joint
What does Sacroiliac Joint pain feel like?
Symptoms experienced with sacroiliac joint dysfunction can include:
- Lower back pain that feels dull, aching, and can range from mild to severe. Lower back pain is typically felt only on one side, but in some cases may be felt on both sides.
- Pain that spreads to the hips, buttocks, and/or One of the most common areas to feel SI joint pain is in the buttocks and upper back or side of the thigh. Pain is typically felt only on one side, but may be felt on both sides.
- Sciatic-like pain in the buttocks and/or backs of the thighs that feels hot, sharp, and stabbing and may include numbness and Sacroiliac joint dysfunction may cause sciatica-like pain that rarely extend below the knee.
- Stiffness and reduced range-of- motion in the lower back, hips, pelvis, and groin, which may cause difficulty with movements such as walking up stairs or bending at the
- Worsened pain when putting added pressure on the sacroiliac joint, such as climbing stairs, running or jogging, and lying or putting weight on one side, such as in prolonged
- Instability in the pelvis and/or lower back, which may cause the pelvis to feel like it will buckle or give way when standing, walking, or moving from standing to
How is Sacroiliac Joint pain treated?
Treatments for sacroiliac joint dysfunction typically focus on alleviating pain and restoring normal motion in the joint.
Initial treatments for sacroiliac joint pain typically include:
- Brief rest period. A rest period of 1 to 2 days may be advised. Resting for longer than a couple days is not recommended, as doing so may worsen stiffness and cause increased pain and generalized deconditioning.
- Applying ice or heat. Ice applied to the low back and pelvis can reduce inflammation and alleviate pain and discomfort. Heat applied around the joint may help relieve pain by reducing muscle tension or spasms.
- Pain medication. Over-the-counter pain relievers (such as acetaminophen) and anti- inflammatory medications (NSAIDs, such as ibuprofen or naproxen) may be recommended for mild to moderate pain relief. Prescription medications such as muscle relaxants or narcotic painkillers may be used during episodes of severe, acute pain. These medications must be used with caution, as they are highly addictive and can cause severe side effects.
- Manual manipulation. Manual manipulation provided by a chiropractor, osteopathic doctor, or other qualified health professional can be effective if sacroiliac joint pain is caused by too little motion (hypomobility). This therapy consists of manual procedures applied to the SI joint and lower back region with the goal of reducing joint fixation and muscle tension, and restoring normal range of motion.
- Supports or braces. When the SI joint is too loose (hypermobile), a pelvic brace can be wrapped around the waist and pulled snugly to stabilize the area. A pelvic brace is about the size of a wide belt and can be helpful when the joint is inflamed and painful.
- Sacroiliac joint injections. A local anesthetic (such as lidocaine or bupivacaine) is injected with an anti-inflammatory medication (such as a corticosteroid) to reduce inflammation and help alleviate pain. The pain relief from a joint injection can help minimize pain when starting a physical therapy program and returning to normal activity levels.
There is no single approach to managing SI joint pain that will work for everyone. A combination of non-surgical treatments is usually necessary for effective pain relief. Additionally, a period of trial-and- error may be needed to find treatments that address specific symptoms.
For those patients who remain refractory to conservative therapies, they may be candidates for Sacroiliac Joint fusion.
What are the surgical treatments for Sacroiliac Joint pain?
The standard surgery used to address SI joint pain is sacroiliac joint fusion. The goal of this procedure is to completely eliminate movement at the sacroiliac joint by grafting together the ilium and sacrum.
Sacroiliac joint fusion is only recommended once non-surgical treatments have been tried for at least 8 to 12 weeks. The patient must have achieved at lease 80% pain reduction after two SIJ injections, and generally failed to achieve prolonged pain relief.
The biggest risk of Sacroiliac Joint fusion is the possibility that surgery won’t alleviate pain, and/or that fusion of the joint will be unsuccessful. There is also the possibility that the fused sacroiliac joint will displace pressure typically absorbed in the pelvis to the lower spine, creating pain and pressure in the lower back (called adjacent segment disease). This complication has been reported in about 5% of sacroiliac joint fusion patients within 6 months of surgery.
There are two surgical systems used for sacroiliac joint fusion, which include the implants that fuse the joint as well as other tools needed to perform the surgery. All minimally-invasive SIJ fusion procedures consist of the following:
- Under deep sedation or general anesthesia, a small incision is made over the lower back and muscles are gently moved to the
- A device is used to drill a small hole through the ilium and access the
- A bone graft is put in place across the joint to encourage bone
- All instruments are removed, and the surgical site is closed using standard sutures.
Recovery from sacroiliac joint fusion typically includes a combination of pain medications, physical therapy, and at-home treatments such as applying heat and ice. Additionally, a pelvic brace may be prescribed to stabilize the pelvis and limit painful movements during healing. The recovery period for SIJ fusion typically lasts between 3 and 6 weeks, but it may take between 3 and 6 months for the Sacroiliac Joint to fully fuse.