Innervation of the human costovertebral joint: Implications for clinical back pain syndromes

Background: The diagnosis of pain in the upper back, shoulder, chest, and a im is often made with considerable confusion and may be accompanied by need less expense and suffering by the patient. Despite the paucity of evidence concerning the tissues and mechanisms responsible for interscapular and aty pical chest pain or "pseudo-angina," practitioners of manual therapy mainta in that manipulation of the costovertebral elements and associated soft tis sues may be helpful in the treatment of these painful conditions. Objective: We have examined the costovertebral complex in humans with respe ct to the presence of immune-like reactivity to neurofilament protein and t he neuropeptide substance P and calcitonin gene-related peptide, markers th at reveal the presence of axons in peripheral tissues. Design: Human costovertebral complexes obtained at autopsy were processed w ith standard histologic examination and immunocytochemical methods to detec t the presence of neurofilaments, substance P, and calcitonin gene-related peptide. Main Outcome Measures: Outcomes were descriptive and did not require statis tical methods Results: All costovertebral joints contained innervation within the anterio r capsule and synovial tissues. In 4 separate cases, the costovertebral joi nts contained large intraarticular synovial inclusions or "meniscoids" foun d to contain small bundles of axons with immune-like reactivity to substanc e P. Axon bundles were identified in serial section with monoclonal antibod ies to neurofilaments as well as with urea-silver nitrate staining. Conclusions: The costovertebral joint has been considered a candidate for p roducing back pain and/or psuedo-angina that may be ameliorated by spinal m anipulation. This study has demonstrated that the costovertebral joint has the requisite innervation for pain production in a similar manner to other joints of the spinal column.