Mechanisms of onset and chronicity of sacroiliac joint pain

Abstract

The sacroiliac joint (SIJ) functions as a shock absorber with a narrow range of motion at the base of the spine, at the interface between the trunk and lower limbs. SIJ disorders occur due to minor subluxation of the joint caused by unintentional or repetitive movements in activities of daily living. Most cases are resolved by early diagnosis with SIJ injections and early treatment including manual therapies, but chronic and severe cases may lead to a severe deterioration in quality of life. Severe cases are classified into three pathological mechanisms: 1) traumatic damage to the surrounding ligaments and joint capsule; 2) inflammation within the SIJ cavity; and 3) enthesopathy of the periarticular ligamentous bone attachment sites. Among the SIJ disorders caused by obvious traumatic accidents, some patients are susceptible to contrast medium leakage from the joint cavity, particularly young patients who may experience chronic SIJ pain due to irreversible joint maladjustment and damage to the periarticular ligaments and joint capsule caused by trauma. Prolonged subluxation of the joint may result in intra-articular inflammation, and similarly, continued excessive traction on the periarticular ligaments, such as the sacrotuberous and long posterior sacroiliac ligaments, may result in enthesopathy similar to severe plantar tendinitis. Intra-articular SIJ injections, extracorporeal shock wave therapies, and SIJ arthrodesis should be considered in severe cases.