Immunohistochemical study of human costotransverse joints: A preliminary investigation.

The human costotransverse joint (CTJ) is the articulation between the posterior tubercle of the ribs with the first through tenth costal facet of the thoracic transverse processes. While the CTJ is well defined anatomically and considered a synovial joint, the human CTJ as a pain generating structure is controversial and not supported from a histological perspective. The objective of the present study was to investigate the histological pain producing properties of CTJ capsule tissue. Ten micron cross-sections at each level (1-10) were stained with H & E or immunostained with antisera against Substance P (SP), calcitonin-gene-related peptide (CGRP), and neuropeptide Y (NPY). Immunoreactivity was confirmed for SP, CGRP, and NPY within the CTJ tissue samples of two unembalmed male cadavers. The presence of previously mentioned neuropeptides suggests that human CTJ is capable of producing pain through somatic and autonomic nervous systems. Therefore, clinicians should consider the CTJ as a differential diagnostic possibility when examining and treating painful thoracic conditions.