Motor Vehicle Accidents
Accidents that occur due to sudden collision with a motor vehicle can cause the bones in the pelvis to shift a bit or become misaligned. This can cause inflammation and pain in the sacroiliac joints.
Sport Injuries
Sport injuries are usually accompanied by a softening of the ligaments and soft tissues in the pelvis. In some cases, the soft tissues also tear and become overstretched. This will cause inflammation of the sacroiliac joints. Sport-related injuries are more common in people who participate in sporting activities and young adults.
Enthesopathy
Enthesopathy is a medical condition that affects the connective tissue (enthesis) that connects tendons or ligaments to bones. When an elevated amount of mechanical stress is exerted on the sacroiliac joint, this may sometimes cause the connective tissue to become degenerate or inflamed, resulting in joint instability and causing sacroiliitis. Inflammation of the connective tissues may also facilitate an immune response that attacks the sacroiliac joint and causes inflammation.