Neurosurgery Coding Alert

Sacroiliac joint: The sacroiliac joint is actually a paired joint, one on each side, where the sacrum (triangular bone at the base of the spine) articulates with the ilium on each side to form the complete pelvic ring. The sacroiliac joint is like a biomechanical mediator between the spine and pelvis.

The sacroiliac joint may be a cause of chronic lower back pain. Your physician may opt for a surgical option when other medical and conservative options have failed to provide pain relief. A minimally invasive surgical (MIS) approach is now being favored to open procedures. 

When does your surgeon do MIS sacroiliac joint fusion? Your surgeon may adopt the MIS approach if the patient has significant sacroiliac pain on clinical assessment and confirms the sacroiliac pain with at least 3 physical examination maneuvers that stress the joint. You may also read that your physician performed a fluoroscopy guided injection of an anesthetic agent to test if the pain can be relieved. Your physician does this to confirm that the pain has origin in the sacroiliac joint. Your physician will also document that the patient failed to respond to at least 6 months of medical treatment. Your physician will make all efforts to rule out other possible causes of pain, such as L5/S1 compression, hip osteoarthritis, and others.

“Imaging that demonstrates localized sacroiliac joint disease rather than hip or lumbosacral disease may also be important,” says Gregory Przybylski, MD, director of neurosurgery at the New Jersey Neuroscience Institute, JFK Medical Center, Edison. “The diagnostic utility of SI joint injections is currently being investigated in a prospective multicenter randomized trial, but can also provide the clinician guidance on the source of SI region pain.  Whereas the medical necessity for SI fusion in the setting of traumatic injury, infection, neoplasm, and associated with long segment thoracolumbar fusions in deformity surgery, the role of SI fusion in managing degenerative conditions of the joint is still being explored.”

In rare cases, your physician may diagnose bilateral sacroiliac pain.

Is fusion possible in bilateral sacroiliac joints? Your surgeon may opt to do a fusion of the sacroiliac joints on both sides. Your surgeon will usually decide to do the fusion on two sides in a serial manner. Your surgeon will adopt bilateral serial fusion when pain/disability continues after the first fusion in spite of conservative treatment and upon a nerve block of the unfused joint, your surgeon is able to able to confirm more than 75% reduction in pain. “The bilateral SI fusion is more likely to be applied in the setting of a long thoracolumbar fusion for deformity,” Przybylski says.

Important: If your surgeon does fusion on both sacroiliac joints in the same operative session, make sure your surgeon documents the medical necessity and also clearly explains why serial fusion is not indicated in the patient.