Sacroiliac Joint (SI Joint) Fusion

Sacroiliac Joint (SI Joint) Fusion

What Is the Sacroiliac Joint?

The sacroiliac (SI) joint is located in the pelvis, connecting the sacrum (the base of the spine) to the iliac bones (hip bones). This joint acts as a shock absorber for the spine, so when it’s injured or not functioning properly, it can cause pain—especially in the lower back.

Common Symptoms of SI Joint Issues

Symptoms of SI joint dysfunction may include:

• Pain in the lower back, buttocks, pelvis, or groin
• Discomfort radiating down one leg
• Tingling, numbness, or weakness in the legs
• Difficulty sitting for long periods or standing up from a seated position
• Feeling like your hips may give out
• Disrupted sleep due to pain

How Is SI Joint Pain Diagnosed?

A physical exam is the first step, often followed by imaging tests such as:

• X-rays
• CT scans
• MRIs

To confirm the diagnosis, doctors may inject a local anesthetic into the SI joint. If this reduces pain by 50% or more, SI joint fusion may be considered a viable treatment.

Who Might Benefit from SI Joint Fusion?

SI joint dysfunction is responsible for 25–50% of lower back pain cases. Initial treatments include:

• Physical therapy
• Injections
• Pain medications

If symptoms persist for over six months despite these treatments, SI joint fusion surgery may be recommended.

Why Choose SI Joint Fusion?

In cases of SI joint instability, fusion surgery can help relieve pain by limiting excessive movement. The procedure is minimally invasive:

• Two small incisions are made
• Tiny titanium implants are inserted
• No muscles or ligaments are cut
• Most patients go home within one or two days

• About 80% report significant pain relief

The SI Joint Fusion Procedure

Before surgery, your doctor will provide detailed instructions, including fasting and medication guidelines.

• A general anesthetic is used
• The procedure takes about an hour
• Surgeons use fluoroscopy for precision
• Implants are placed through small incisions to stabilize the joint

Post-surgery:

• Most patients are discharged within two days
• Pain is managed with medications and ice
• Crutches are typically needed for 4–6 weeks
• Full recovery takes around six months
• Most people return to work within six weeks
• Avoid strenuous activities until cleared by your doctor

New, Less Invasive SI Joint Treatments

Advanced technologies now offer non-invasive alternatives, such as the SiLO™ Joint Fusion Procedure, which involves:

• A small incision to access the SI joint
• A guided tube (GhostTube™) to visualize the area
• A decorticator to stimulate bone growth
• A biologic bone graft (made from human cortical bone) inserted into the joint
• Channels in the implant to secure it and allow for additional graft material

A newer FDA-approved version, the SiLO TFX™ MIS SI Joint Fixation System, helps stabilize the ilium and sacrum while promoting fusion. This may offer relief for patients with joint damage or instability.

Possible Diagnosis: Sacroiliac Joint Dysfunction

If you suspect SI joint dysfunction, consult with a spine or pain specialist to discuss diagnosis and the best treatment plan.