Anatomy and pathophysiology of the sacroiliac joint.

The sacroiliac joint as a source of chronic pain has been a subject of debate for a long period of time. This controversy stems from the inherent anatomic location of the sacroiliac joint. Adjacent spinal structures may cause pain to be referred to the sacroiliac joint, thus making a precise diagnosis difficult. The most reliable method to establish the diagnosis of sacroiliac arthralgia is fluoroscopic-guided intra-articular injection of a local anesthetic preceded by a sacroiliac arthrogram. Although there are many therapeutic options for sacroiliac joint syndrome, the ideal treatment has not yet been discovered. There is evidence that intra-articular viscosupplementation of the sacroiliac joint with hylan can consistently and reliably induce a prolonged analgesic response in sacroiliac joint syndrome. Viscosupplementation restores joint homeostasis, allows increased joint motion, and induces analgesia. Hylan is highly viscoelastic hyaluronan (hyaluronic acid), and is capable of increasing the viscoelastic properties of synovial fluid.