The sacroiliac joint, often known as the SI joint, is the joint that links your lower spine to your pelvis. SI joint can sometimes cause lower back and/or leg pain. Leg pain caused by dysfunction of the sacroiliac joint can be difficult to distinguish from radiating leg pain caused by a lumbar disc herniation (sciatica), as the symptoms can be quite similar.
For many years, the sacroiliac joint was thought to be a common cause of low back and/or leg pain, irrespective of the fact that accurate diagnostic testing was difficult, leaving many medical practitioners skeptical. It is currently believed that the sacroiliac joint is responsible for 15% to 30% of occurrences of lower back pain.
Sacroiliac joint injections may be recommended if the symptoms are not getting improved.