This condition is caused by the inflammation of the spinal joints (facet joints and intervertebral disc), which often occurs in conjunction with inflammation in other joints of the body, especially the pelvic joints (sacroiliac joint). Genetic factors or autoimmune diseases may be responsible, and the condition is usually found in individuals between the ages of 20 and 40 (young adults). Common diseases include ankylosing spondylitis and psoriatic arthritis.