Thoracic Pain Maps
Thoracic facet joints are implicated as pain generators in approximately 34% to 42% of patients presenting with chronic thoracic spinal pain.[1] Innervation is similar to other spinal regions, thoracic facet joints receive bisegmental innervation from the medial branches of the dorsal rami of the spinal nerves at the same level and the level above.
Diagnosing thoracic spine pain is a minefield. One has to contend with the discs, and three synovial joints at each unilateral paravertebral segment (costotransverse, costovertebral, and facet joint). Furthermore, if the patient has upper thoracic pain one has to consider somatic referred pain from the cervical spine (disc, nerve root, or facet joint).
Thoracic ZA Joints
Mapping Methodology: The primary study mapping thoracic facet pain patterns was conducted by Dreyfuss et al. (1994). They used provocative intra-articular injections of contrast medium into the facet joints of asymptomatic volunteers, recording the quality, intensity, and distribution of the evoked pain.
Thoracic facet joint pain is felt in the parasagittal region and doesn't cross the midline. There is significant overlap between the referral zones of adjacent segmental levels; most areas of the thoracic back fall within the potential referral zones of 3 to 5 different facet joints.
Referral to the anterior chest wall or abdomen is uncommon or absent based on these experimental studies.[2] (Though some clinical reports suggest T3-4/T4-5 may refer towards the chest and T11-12 towards the iliac crest).
Thoracic Costotransverse Joints
These joints, connecting the ribs to the transverse processes and vertebral bodies respectively, are suspected sources of thoracic pain. Dysfunction may contribute to conditions like T4 syndrome (characterized by upper thoracic pain, arm/hand paresthesias, headache) or mimic visceral pain.Costotransverse joints are innervated by the lateral branches of the thoracic dorsal rami.
Mapping Methodology: Young et al. (2008) mapped costotransverse joint pain patterns using provocative intra-articular contrast injections in asymptomatic volunteers, similar to the Dreyfuss study for facet joints.41
- Pain Referral Patterns (Costotransverse Joints - Young et al.):
- Pain was felt primarily superficially over the injected joint, in the parasagittal region.
- Pain quality was described as a deep, dull ache or pressure sensation.
- Pain did not cross the midline.
- Referred pain was minimal in this study; only stimulation of T2 joints produced limited cranial and caudal spread over two segments.Importantly, no pain referral to the chest wall, upper extremity, or pseudovisceral patterns were reported following costotransverse joint stimulation in this volunteer study.
Costotransverse joint pain is felt in the parasagittal thoracic spine. It does not or only rarely causes midline or arm pain. It does not cross the midline.
Soft Tissues
Kellgren (Interspinous Ligaments)
Kellgren in 1939 produced the original referred pain maps from noxious stimulation of the interspinous ligaments. Kellgrenās findings were reproduced by Feinstein et al. 1954 who produced similar maps. Pain patterns are not identical between studies, and vary between individuals.
Feinstein ("Musculotendinous Interspinous Tissues")
Thoracic Discs
Thoracic disc herniation or degeneration is less common than in the cervical or lumbar spine but can be a source of pain.72 Pain may be localized axially or refer, potentially mimicking patterns associated with cervical disc referral (Cloward areas).72
See Also
References
- ā Manchikanti, Laxmaiah; Boswell, Mark V; Singh, Vijay; Pampati, Vidyasagar; Damron, Kim S; Beyer, Carla D (2004-05-28). "Prevalence of facet joint pain in chronic spinal pain of cervical, thoracic, and lumbar regions". BMC Musculoskeletal Disorders. 5 (1). doi:10.1186/1471-2474-5-15. ISSN 1471-2474.
- ā Piraccini, Emanuele; Byrne, Helen; Calli, Morena; Maitan, Stefano (2017-01-13). "High Abdominal Wall Pain: An Unusual Radiation in Thoracic Facet Joint Syndrome". Pain Medicine: pnw331. doi:10.1093/pm/pnw331. ISSN 1526-2375.
- ā Dreyfuss, Paul; Tibiletti, Claire; Dreyer, Susan J. (1994-04). "Thoracic Zygapophyseal Joint Pain Patterns: A Study in Normal Volunteers". Spine (in English). 19 (7): 807ā811. doi:10.1097/00007632-199404000-00014. ISSN 0362-2436. Check date values in:
|date=(help) - ā Young et al.. Thoracic costotransverse joint pain patterns: a study in normal volunteers. BMC musculoskeletal disorders 2008. 9:140. PMID: 18922181. DOI. Full Text.
