Sacroiliac Joint Arthrodesis

What is Sacroiliac Joint Arthrodesis?

Sacroiliac (SI) joint arthrodesis is a surgical procedure employed for the treatment of sacroiliac joint dysfunction and/or inflammation/pain. The procedure involves surgical immobilization of the SI joint by fusion of the sacrum and ilium bones using instrumentation, bone graft, or both.

• Sacroiliac joint dysfunction or sacroiliac joint pain is one of the common causes of low back pain. Sacroiliac joint dysfunction may occur as a result of:
• Traumatic injuries caused when there is a sudden impact
• Biomechanical problems such as a twisted pelvis, leg length discrepancies or muscle imbalances
• Inflammatory joint conditions such as arthritis and ankylosing spondylitis
• Hormonal changes during pregnancy

Anatomy of the SI Joint

The sacrum is the triangular-shaped bone at the bottom of the spine, below the lumbar spine. The sacroiliac joint is a large joint in the body, formed by the connection of the sacrum and the right and left iliac (pelvic) bones. The sacroiliac joint acts as a shock-absorbing structure. These joints only have a small amount of movement and transmit all the forces of the upper body to the lower body. 

Indications for Sacroiliac Joint Arthrodesis

Sacroiliac joint arthrodesis is indicated when non-surgical treatment methods such as medications, injections, physical therapy, and bracing have failed to treat sacroiliac joint dysfunction/inflammation and pain. Common indications of SI joint arthrodesis include:

• Severe low back, pelvis, or groin pain that makes everyday activities difficult
• Stiffness and restricted movement in the low back, pelvis, groin, or legs
• Instability in the lower back and pelvis, causing difficulty or pain while walking, standing, or moving from standing to sitting position or vice versa
• Exacerbation of pain after standing or sitting or lying on the affected side for a prolonged period of time
• When conservative treatment measures of at least 8 to 12 weeks have failed to provide any satisfactory results

Preparation for Sacroiliac Joint Arthrodesis

Pre-procedure preparation for sacroiliac joint arthrodesis will involve the following steps:

• A thorough examination by your doctor is performed to check for any medical issues that need to be addressed prior to surgery.
• Depending on your medical history, social history, and age, you may need to undergo tests such as blood work and imaging to help detect any abnormalities that could threaten the safety of the procedure.
• You will be asked if you have allergies to medications, anesthesia, or latex.
• You should inform your doctor of any medications, vitamins, or supplements that you are taking.
• You should refrain from medications or supplements such as blood thinners, aspirin, or anti-inflammatory medicines for 1 to 2 weeks prior to surgery.
• You should refrain from alcohol or tobacco at least a few days prior to surgery.
• You should not consume any solids or liquids at least 8 hours prior to surgery.
• You will be placed on a special diet prior to surgery and laxatives may be used to clean out your bowel.
• You may be instructed to shower with an antibacterial soap the night prior to surgery to help lower your risk of infection after surgery.
• Arrange for someone to drive you home as you will not be able to drive yourself after surgery.
• A written consent will be obtained from you after the surgical procedure has been explained in detail.

Procedure for Sacroiliac Joint Arthrodesis

Sacroiliac joint arthrodesis is performed by grafting one or both sides of the sacrum to the ilium to promote bone growth along the joint. The fusion occurs following the surgery during the healing process and is accomplished utilizing a bone graft and/or implanted instrumentation.

A minimally-invasive approach with a small incision in the buttock is the common method employed during SI joint arthrodesis as open SI joint arthrodesis is linked with higher complication rates and extensive healing processes. In general, the minimally invasive SI joint arthrodesis surgery involves the following steps:

• You will lie face down on the operating table under the influence of general anesthesia.
• Your surgeon makes a small surgical cut of 2 to 3 cm on the side of the buttock and the gluteal muscles are gently moved out of the way to reach the ileum.
• A small guide pin is placed via the side of the ilium to make a small hole enabling access to the ilium. This small opening is then drilled or broached through the ilium to create a tunnel for the implants to connect with the sacrum.
• If a bone graft is warranted, the sacroiliac joint is freed from soft tissues and cartilage, and a bone graft is inserted into the joint space.
• The implant instruments are directed along the tunnel in the ilium and are placed in an exact position using pins, screws, or a mallet.
• Saline solution is used to thoroughly irrigate the surgical site to remove any debris and the surgical cut is closed in layers utilizing standard sutures.

Postoperative Care and Recovery

In general, postoperative care instructions and recovery after sacroiliac joint arthrodesis will involve the following steps:

• You will be transferred to the recovery area where your nurse will closely observe you for any allergic/anesthetic reactions and monitor your vital signs as you recover. 
• You may need to stay in the hospital for 2-3 days before discharge to home.
• You may experience pain, inflammation, and discomfort in the operated area. Pain and anti-inflammatory medications are provided as needed.
• Application of cold and heat therapy on the low back area is also recommended to reduce inflammation and pain.
• Walking and moving around in bed is strongly encouraged to prevent the risk of blood clots.
• A cane or walker is recommended for 4 to 6 weeks to decrease stress on the SI joint as it fuses and promote healing.
• A sacral belt may also be recommended to help stabilize the joint and restrict movements that may aggravate pain and obstruct healing.
• Antibiotics are prescribed as needed to address the risk of surgery-related infection.
• Your diet is slowly advanced post surgery. You will start with clear liquids, then progress to having normal solid foods, as tolerated.
• Instructions on surgical site care and bathing will be provided.
• Eating a high-calcium and low-fat diet is strongly recommended to promote healing and a faster recovery.
• To prevent straining on the toilet, a high-fiber diet and drinking 8 to 10 glasses of water daily is recommended to keep stools soft. Laxatives or stool softeners may also be recommended as needed.
• If you are a smoker, refrain from smoking for a specific period of time as it can negatively affect the healing process.
• Refrain from strenuous activities and lifting anything heavier than 10 pounds for the first couple of months. Gradual increase in activities over a period of time is recommended.
• A physical therapy protocol is recommended to help strengthen low back, pelvic, and leg muscles and optimize their function.
• Most patients will need to take off work at least a month to rest and promote healing. Walking is a good exercise and is strongly recommended to improve your endurance.
• Refrain from driving until you are fully fit and receive your doctor’s consent.
• You will be able to resume your normal activities in 2 to 3 weeks but may have certain activity restrictions.
• A periodic follow-up appointment will be scheduled to monitor your progress.

Risks and Complications

Sacroiliac joint arthrodesis is a relatively safe procedure; however, as with any surgery, some risks and complications may occur, such as:

• Infection
• Blood loss
• Neurovascular injury
• Damage to musculoligamentous structures
• Post-procedure pain, requiring narcotics for relief
• Blood clots
• Anesthetic reactions