FAQs on Sacroiliac Joint Injections (SI Joint) – info from a Phoenix Pain Clinic

The sacroiliac (SI) joints are located where the sacrum connects to the right and left iliac bones. These two joints connect the spine to the pelvis, and they can develop arthritis. A sacroiliac joint injection involves injecting a solution into one or both of these joints.

What causes SI joint arthritis?

Because the SI joints support the entire weight of the upper body, this places a great deal of stress on them. Arthritis occurs due to wear-and-tear on the joints, and obesity is a contributing factor. SI joint arthritis is the direct result of cartilage loss and aging. In addition to arthritis, other types of SI joint problems include SI joint dysfunction, SI joint strain, and SI joint inflammation.

Why is the SI joint injection done?

The SI joint injection is an effective method for diagnosing dysfunction of this joint. The doctor injects a numbing agent to pinpoint the source of pain. In addition, this injection is used to treat SI joint arthritis by injecting a corticosteroid into the joint for long-term pain relief and to decrease inflammation.

How is the SI joint injection performed?

The doctor will position the patient on his/her stomach, using pillows under the abdomen for support. Once the injection site is cleansed with an antimicrobial solution, the skin is numbed with an anesthetic agent. After a few minutes, the doctor will insert a small needle into the SI joint. To assure correct placement of the needle, the doctor uses a special x-ray guiding machine (fluoroscopy). The corticosteroid and anesthetic is injected into the joint, and the needle is then removed. Depending on the condition, both joints can be injected during the same procedure.

What happens immediately after this procedure?

As the anesthetic wears off, you may notice some soreness at the injection site. Many patients also complain of temporary loss of sensation at the injection site, weakness of the hips and legs, and slow motor coordination. These side effects are temporary and resolve in a few hours. A nurse monitors you immediately after the procedure for a few minutes. You should rest for a few hours and gradually return to usual activities as tolerated.

How many sacroiliac joint injections will I need?

Because the corticosteroid is a long-acting steroid, it offers long-term pain relief. It usually begins working within 2-3 days. Many patients enjoy pain relief after only one joint injection (to each hip region). However, other patients require a series of three injections to each joint, which is done within a six-month period. This gives maximum effectiveness for arthritis symptoms.

What risks and complications are associated with the SI joint injection?

There are very few risks to consider, but these may occur: bleeding, infection, and allergic reaction. Since this is a simple joint injection, complications such as nerve damage and blood vessel injury are rare. Side effects to the steroid medication include weight gain, increased appetite, anxiety, moodiness, and trouble sleeping.

What is the efficacy rate of sacroiliac joint injections?

Researchers report that the use of an anesthetic and corticosteroid for SI joint pain is 90% effective for relief of symptoms. Most clinical studies show that sacroiliac joint injections are a safe, useful option for chronic arthritis.