It is an inflammation of the sacroiliac joint, causing pain in the lower back and buttocks, sometimes spreading to the thigh. Causes can be varied: degenerative changes, trauma, pregnancy, rheumatological diseases (e.g. ankylosing spondylitis), or changes in load after spinal surgery. Pain is most often exacerbated by prolonged standing, walking, changing positions or turning over in bed. Diagnostic injections may be used to confirm the diagnosis and treatment may include anti-inflammatory drugs, physiotherapy, intraspinal corticosteroid injections, sacroiliac nerve block, radiofrequency ablation or cryoneurolysis.