SI JOINT FUSION
The sacroiliac joint joins the hip bones to either side of the sacrum and serves largely as a stress absorber between the lower body and the torso. The point where the base of the spine attaches to the pelvis is also known as this joint. A synovial joint and the sacroiliac ligaments make up the sacroiliac joint.
Lower back pain, as well as pelvic, groin, and hip pain, can be caused by sacroiliac joint (also known as the SI joint) dysfunction. Too much motion, too little motion, or joint inflammation can all cause sacroiliac joint trouble.