The spinal epidural space

The validity of the concept of an epidural 'space' within the vertebral canal is questioned. An attempt is made to locate the 'space' morphologically, developmentally, and topographically. Following Parkin and Harrison (1985), it is agreed that no actual 'space' exists in the intact living subject. It is suggested that the spinal epidural space satisfies the criteria of Haines (1991) to be considered a "true potential space." As such, and by analogy with other body cavities, it would be better termed the 'epidural cavity', as it was in the 1983 edition of the Nomina Anatomica.