Zygapophysial joint (z-joint) better known as a facet joints have been know to cause as high as 55% of chronic neck pain (Manchikanti et al). Facet joint pain has documented pain referral patterns that can help determine generating structures of perceived pain. Pain mapping of the cervical facet joints have been performed in numerous studies using intra-articular injections of contrast dye, electrical medial branch stimulation, or facet joint block injections.
A study in 2007 performed by Cooper, Bailey, and Bogduk looked at cervical zygapophysial joint pain patterns and the prevalence of pain at particular segments. They used 194 patients seen between 1999 and 2003 all having neck pain longer than 6 months. Each patient created a map of their pain and then underwent a diagnostic block at the segmental level selected by the physician. If the block were negative (no relief of pain) they would continue blocking segmentally until receiving a positive result (complete relief of pain). They found that facet joint referral patterns are similar to other study outcomes. The referral patterns are as follows…
Based on these outcomes they found that the most common site of cervical facet joint pain is C2-3 (36%), C5-6 (35%), and C6-7 (17%). This study found C3-4, C4-5, and C1-2 to be symptomatic in less than 5% of the group. Clinically these images and this study are important because it can break down facet pain into 2 sections, upper and lower.
Upper cervical (C1-2, 2-3, 3-4) facet symptoms are found to be in the occipital and suboccipital regions that can refer to the parietal and temporal regions.
Lower cervical (C4-5, 5-6, 6-7) facet symptoms presented in the neck on the side of pathology below the occiput, scapula, and lateral arm. Pain in the lateral arm and scapula are typically seen in C5-C6 facet dysfunction but more inferior scapular pain without the presence of lateral arm pain is suspected to be C6-C7.
If you compare these facet pain patterns to Cloward areas you may notice that they are similar. You also realize that these are images of single specific levels and many patients come with numerous levels of dysfunction. These images are great for understanding cervical spine pain but your evaluation will help you further rule out sources of pain. Hope you enjoyed!