The evidence for the spinal segmental innervation of bone

Dermatomes and myotomes are areas of skin and muscle, respectively, that are innervated by single spinal segmental nerves, and reflect a principle of organization that appears in just about every clinical textbook available today. The evidence for the existence of dermatomes and myotomes has a long and substantial history. A lesser known, but similar principle exists for the skeletal system. The term "sclerotome" was first used in the non-embryological sense by Inman and Saunders ([1944] J. Nerv. Ment. Dis. 99:660-667) to define a region of bone and periosteum that is innervated by a single spinal segment. It is used by clinicians in many healthcare settings to aid in the diagnosis and description of a variety of deep and/or skeletal tissue pathologies and pain syndromes. In this article, the evidence for the existence of the sclerotomes is described in detail. Early clinical studies that define the sclerotomes, evidence from studies of the development of skeletal innervation, and the contributions of anatomical and physiological investigations are explored. It is suggested that there is in fact little direct evidence for the existence of discrete spinal segmental innervation patterns for the skeleton.