Sacroiliac joint dysfunction (SI Joint Pain): : Pain arising from abnormalities or injury of the sacroiliac (SI) joints. The SI joints connect the spine to the pelvis and are formed by the connection of the sacrum and the right and left iliac bones. The sacrum, or lower portion of the spine, is made up of five vertebrae that are fused together and do not move. The iliac bones are the two large bones that make up the pelvis. Many conditions can cause pain arising from the sacroiliac joint, including degenerative arthritis (osteoarthritis), gout, rheumatoid arthritis, conditions that alter the normal walking pattern, and pregnancy (due to a normal relaxation of the ligaments in the joint that prepares the pelvis for childbirth). Treatment can involve anti-inflammatory medications, physical therapy, and/or surgery.