SUBSTANCE-P INNERVATION OF LUMBAR SPINE FACET JOINTS

Sixteen adult human lumbar spine facet joints were harvested from pati ents undergoing various lumbar spine procedures. Diagnoses included de generative disc disease, adult spinal deformity, facet joint degenerat ive arthritis, and degenerative spondylolisthesis. Facet joints were p rocessed for routine hematoxylin and eosin staining. Immunohistochemic al analysis was performed using a monoclonal antibody to substance P. All facets grossly exhibited evidence of degenerative disease, includi ng cartilage surface irregularity and fibrillation. Histological exami nation of facets obtained from patients with degenerative spinal condi tions demonstrated erosion channels extending through the subchondral bone and calcified cartilage into the articular cartilage. Immunostain ing showed the presence of substance P-positive nerve fibers within th ese erosion channels, and also within marrow spaces. The presence of s ubstance P nerve fibers within subchondral bone of degenerative lumbar facet joints implicates this type of joint in the etiology of low bac k pain.