Sacroiliac joint pain: Diagnosis and treatment

Introduction Over the last two decades, the sacroiliac joint (SIJ) has increasingly been recognized as an anatomical source of pain that figures in the differential diagnosis of a patient presenting with low back pain (LBP) and/or buttock pain with or without more distant referred pain.1-7 The SIJ is innervated and thus has the potential to be a source of pain.2,8-13 As SIJ pain refers into the buttock and iliac crest near the posterior-superior iliac spine, and also into the groin, abdomen, and leg including the foot,14,15 it can be confused with referred pain from other sources, particularly from the lumbar intervertebral disc, lumbar zygapophysial joint (ZJ), hip joint and radicular pain. It is essential that the clinician recognizes these potentially confounding features and takes adequate steps to differentiate between SIJ pain and other pain presentations. In the early 1900s, the SIJ was thought to be the principal source of LBP,16 and an important cause of “sciatica”.17 Subsequently, and particularly after the discovery of the disc prolapse, it was considered that the lumbar spine and in particular the lumbar intervertebral disc was responsible for most back problems.17 Acknowledgement of the SIJ as a source of pain in the ensuing decades commenced in rheumatological literature, but this largely related to seronegative arthropathies, and case reports of various rare infections and tumours.18,19 Subsequently there have been substantial developments in the basic sciences relating to the SIJ, initially and primarily in the osteopathic, physiotherapy, and chiropractic literature,18,19 and later in biomechanical and radiological literature.20-26 The advent of imaging-controlled diagnostic interventions has allowed for a more rational approach to diagnosis, and as a result there is again an increasing awareness that the SIJ is an important cause of LBP and referred pain into the pelvis and leg. It is now estimated that the SIJ may be the cause of 15-38% of all cases of LBP.4,27-30 While the SIJ can be a source of pain in various disease states, this article is restricted to mechanical disorders.