The sacroiliac (SI) joint is a low-motion joint that connects the pelvis to either side of the sacrum (tailbone), acting primarily as a shock-absorber between the lower body and torso. This joint is the point where the base of the spine connects to the pelvis.
Dysfunction in the SI joint can produce significant lower back pain, as well as hip/buttock pain and pain in the backs of the legs. Sacroiliac joint dysfunction can be the result of too much motion, too little motion, or inflammation of the joint.
There is evidence that those who have undergone a lumbar spinal fusion are at a heightened risk for SI joint pain.
In a sacroiliac joint fusion, two small incisions are made over the sacroiliac joint and two small bone grafts are placed in the sacroiliac joint to stabilize it and prevent movement, thereby reducing pain from the joint. There are no screws or metal hardware placed in the joint or pelvis with this procedure. The recovery period is brief, typically less than one week, and no bed rest is required.