Radiographic evaluation of the corporotransverse ligament at the L5 intervertebral foramen: a cadaveric study

An extraforaminal ligament bisecting the L5/S1 intervertebral foramen and known as the corporotransverse ligament was studied in 15 adult embalmed cadavers. Its relationship to the L5 ventral ramus, sympathetic chain and gray ramus communicans was observed and recorded. The corporotransverse ligament has been implicated as a site for potential entrapment of the L5 nerve. The purpose of this study was to determine if the ligament could be detected radiographically. A single sample spine containing the ligament was hemisected and the neural, vascular and adipose tissue removed. Plain film, linear tomography and axial computed tomography (CT) slices were evaluated and the results compared. The corporotransverse ligament was not visualized by either plain film or linear tomography. Due to its superior resolution in the imaging of soft tissues, the ligament was well demonstrated by CT. Further studies with the neural tissue intact, imaging with magnetic resonance and in vivo comparison studies are recommended.