SI Joint Fusion

Overview

Your sacroiliac (SI) joints connect the base of your spine to your pelvis. When one of these joints is worn, loose or inflamed, it can cause ongoing pain in the low back, buttock or hip. Many people improve with therapy, a belt, injections or radiofrequency treatment.

GSMC is led by Dr. Dharam Mann, who completed fellowships in pain management, cardiac anesthesia and critical care at Massachusetts General Hospital/Harvard.

For some people whose pain continues, minimally invasive SI joint fusion may help. Through a small incision, 2 to 3 titanium screws are placed across the joint to hold it steady. No separate bone graft is taken from your body. Consults are available at all 7 GSMC offices in Ocean and Monmouth County, and our providers help decide who may be a good fit.

What it is

SI joint fusion aims to hold the SI joint steady so it moves less, which may ease pain that comes from extra motion in the joint. It is a minimally invasive fusion: it is done through a small incision with live X-ray guidance rather than a large open incision. GSMC uses the CornerLoc™ SI joint system with a posterolateral approach: the screws are placed from the back, angled toward the joint.

• 2 to 3 titanium screws are placed at right angles to the SI joint, passing from the ilium (pelvis) across the joint into the sacrum.
• According to the manufacturer, this angled path is designed to avoid the gluteal (buttock) muscles, artery and nerves that a straight side approach would pass near.
• The screws are meant to steady the joint right away. Healing around the screws continues over the following months.

Who is a candidate for SI joint fusion

SI joint fusion may be considered for people who have:

• Ongoing low back, buttock or hip pain from the SI joint, with exam tests that point to the joint
• SI joint pain confirmed by clear short-term relief from a diagnostic SI joint injection
• SI joint injections or radiofrequency ablation (RFA) that no longer help, or help only for a short time
• Pain that has not improved after about six months of conservative care, such as therapy, an SI belt, medicines and injections

What the procedure involves, step by step

1. Confirming the source: we confirm the SI joint is the pain source with an exam, imaging and usually a diagnostic SI joint injection.
2. Before the procedure: we review your health, medicines and allergies. Blood thinners may need to be paused, but only with approval from the doctor who prescribes them.
3. Getting ready: you lie face down and receive sedation or anesthesia. The skin is cleaned and numbed.
4. Guidance: live X-ray (fluoroscopy) is used to find the SI joint and guide every step.
5. Small incision: a small incision is made in the lower back or buttock area.
6. Screws: 2 to 3 titanium screws are placed across the joint, from the ilium into the sacrum, using the posterolateral approach.
7. Going home: the incision is closed and covered. Many people go home the same day after a period of monitoring.

What to expect on procedure day

• Where: SI joint fusion is done at Manchester Surgery Center in Whiting. Your care team will give you arrival time and instructions in advance.
• Before you arrive: follow the eating, drinking and medicine instructions you are given. Do not stop a blood thinner unless the doctor who prescribes it approves.
• Check-in: the team reviews your health history, medicines and allergies, and answers your questions.
• The procedure: you receive sedation or anesthesia, lie face down, and the screws are placed through a small incision using live X-ray guidance.
• Afterward: you rest in a recovery area while the team monitors you. Many patients go home the same day. Plan to have an adult drive you home.

SI joint fusion recovery timeline

Recovery is different for each person. This is a general guide, and your care team will guide you on your own plan.

• First few days: soreness at the incision is common. Keep it clean and dry as instructed and rest as advised.
• First several weeks: many patients limit weight on the treated side, sometimes with crutches or a walker, and avoid bending, lifting and twisting.
• Following weeks: physical therapy often starts, and activity increases step by step as your care team advises.
• Over the following months: healing around the screws continues. Follow-up visits check your progress and update your activity plan.

Who may not be a good fit

SI joint fusion may not be right for people whose pain comes mainly from another source (such as the hip or lumbar spine), people with an active infection, a tumor or fracture in the area, severe osteoporosis, a metal allergy, or health problems that make sedation or anesthesia unsafe. Pregnancy is also a reason to wait.

CornerLoc and other SI joint fusion systems

Several implant systems are used for SI joint fusion. A main difference between them is the direction the implants are placed from.

• Lateral approach: many systems place implants from the side of the pelvis, passing through the buttock area to reach the joint.
• Posterolateral approach (CornerLoc™): the screws are placed from the back, angled toward the joint. According to the manufacturer, this path is designed to avoid the gluteal muscles, artery and nerves that a side approach passes near.

Each system has its own design, and the right option depends on your anatomy and history. GSMC uses the CornerLoc system. Ask your provider about the approach and what it means for you.

Risks in brief

Every procedure has risks. These include infection, bleeding or bruising, nerve irritation, a screw that does not sit as planned, ongoing pain and, rarely, the need for another procedure. Sedation or anesthesia also carries risks. Our team will review your specific risks with you.

Alternatives

Other options may include physical therapy, an SI belt, medicines, SI joint injections and radiofrequency ablation of the nerves to the SI joint. You can also ask for a second opinion.

SI Joint Fusion patient brochure (print-ready PDF)

Our 4-page guide covers the SI joint, symptoms, diagnosis, options to try first, minimally invasive SI joint fusion with 2 to 3 titanium screws placed with the CornerLoc™ system and its posterolateral approach, recovery, risks and insurance. All GSMC providers evaluate patients and help select who may be a good fit.

Print at home/office (Letter) Print shop version (with bleed)

CornerLoc™ is a trademark of Foundation Fusion Solutions, LLC (dba CornerLoc). GSMC is not affiliated with the manufacturer.

SI joint fusion FAQ

Insurance

GSMC participates with all Aetna plans, including Aetna HMO, and with many other insurance plans. Coverage for a specific procedure depends on your plan and may need prior authorization; call 732-202-3000 to verify. Our team can help check your benefits before treatment.

See accepted insurance

Related pages

Related conditions

• SI joint dysfunction
• Low Back Pain
• Back Pain

Related treatments and resources

• SI joint injection
• Radiofrequency ablation
• SI Joint Fusion brochure (PDF)