Published online Nov 27, 2015. doi: 10.5313/wja.v4.i3.49
Peer-review started: May 7, 2015
First decision: July 30, 2015
Revised: September 2, 2015
Accepted: September 10, 2015
Article in press: September 16, 2015
Published online: November 27, 2015
The zygapophysial joints (z-joints), together with the intervertebral disc, form a functional spine unit. The joints are typical synovial joints with an innervation from two medial branches of the dorsal rami. The joint capsule and the surrounding structures have an extensive nerve supply. The stretching of the capsule and loads being transmitted through the joint can cause pain. The importance of the z-joints as a pain generator is often underestimated because the prevalence of z-joint pain (10%-80%) is difficult to specify. Z-joint pain is a somatic referred pain. Morning stiffness and pain when moving from a sitting to a standing position are typical. No historic or physical examination variables exist to identify z-joint pain. Also, radiologic findings do not have a diagnostic value for pain from z-joints. The method with the best acceptance for diagnosing z-joint pain is controlled medial branch blocks (MBBs). They are the most validated of all spinal interventions, although false-positive and false-negative results exist and the degree of pain relief after MBBs remains contentious. The prevalence of z-joint pain increases with age, and it often comes along with other pain sources. Degenerative changes are commonly found. Z-joints are often affected by osteoarthritis and inflammatory processes. Often additional factors including synovial cysts, spondylolisthesis, spinal canal stenosis, and injuries are present. The only truly validated treatment is medial branch neurotomy. The available technique vindicates the use of radiofrequency neurotomy provided that the correct technique is used and patients are selected rigorously using controlled blocks.
Core tip: This review emphasizes the importance of the zygapophysial joints (z-joints) as a pain generator. Taking the historic or the physical examination are not helpful in identifying z-joint pain. The prevalence of z-joint pain increases with age, and it often comes along with other pain sources. The focus is on the significance of z-joint pain in elaborated patient groups in which z-joint pain is clinically relevant but does not occur as an isolated and independent disease. Diagnostic methods and the treatment with radiofrequency neurotomy are discussed.