What is lumbosacral facet syndrome?

Updated: Nov 19, 2018
  • Author: Gerard A Malanga, MD; Chief Editor: Craig C Young, MD  more...
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The facet joints are a pair of joints in the posterior aspect of the spine. Although these joints are most commonly called the facet joints, they are more properly termed the zygapophyseal joints (abbreviated as Z-joints; also commonly spelled as "zygapophysial joints"), a term derived from the Greek roots zygos, meaning yoke or bridge, and physis, meaning outgrowth. This “bridging of outgrowths” is most easily seen from a lateral view, where the Z-joint bridges adjoin the vertebrae. The term facet joint is a misnomer because the joint occurs between adjoining zygapophyseal processes, rather than facets, which are the articular cartilage lining small joints in the body (eg, phalanges, costotransverse and costovertebral joints). This joint is also sometimes referred to as the apophyseal joint or the posterior intervertebral joint.

As is true of any synovial joint, the Z-joint is a potential source of pain. In fact, the Z-joint is one of the most common sources of low back pain (LBP). The history and presence of Z-joint pain has been well published. However, despite all of these studies, the diagnosis of Z-joint–mediated pain remains a challenge because no history findings or examination maneuver has been found to be unique or specific to this entity. [1, 2]  Schwarzer et al and other authors have reported up to a 45% false-positive diagnostic rate when the physical examination findings are correlated to diagnostic medial branch blocks of the posterior rami. [3, 4, 5, 6, 7]

Authors have concluded that in most cases, Z-joints are not the single or primary cause of LBP. In many cases, Z-joint pain is mistaken for discogenic pain. Thus, many clinicians agree that correlating historical or physical examination findings with pain emanating from the Z-joint is a challenge. This review may help broaden the clinician's knowledge of this entity and may assist in making the diagnosis of lumbosacral facet joint syndrome.

For excellent patient education resources, see eMedicineHealth's patient education articles Low Back PainSprains and Strains, and Slipped Disk.

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