Fibrous Connection Between Cervical Nerve and Zygapophysial Joint and Implication of the Cervical Spondylotic Radiculopathy: An Anatomic Cadaveric Study.

STUDY DESIGN: Observational, anatomical, cadaveric study. OBJECTIVE: We anatomically investigated the fibrous connection between the cervical nerves and the zygapophysial joint capsules. SUMMARY OF BACKGROUND DATA: Cervical spondylotic radiculopathy is caused by the compression of the cervical nerves as the static factor and head and neck movements as the dynamic factor. To understand the dynamic pathology of cervical spondylotic radiculopathy, the anatomic relationship between the cervical nerves and the zygapophysial joints needs to be investigated in detail. METHODS: In 11 cadavers, we dissected both sides from the C5 to C7. For macroscopic examination, we observed structures connecting the cervical nerves and the zygapophysial joints in 18 cervical nerves from three cadavers. In 14 sides of eight cadavers, we histologically analyzed the fibrous structures and their attachments. RESULTS: Macroscopically, the fibrous band connected the cranial surface of the cervical nerve to the lateral and inferior aspects of the transverse process. In four of 18 nerves, the fibrous bands were divided into two fascicles by loose connective tissues. In addition, the fibrous bands extended along the dorsal aspect of the posterior tubercle of the transverse process and attached to the zygapophysial joint capsule. Histologically, densely stained fibrous tissues overlaid the zygapophysial joint capsule and extended to the recess between the posterior tubercle and inferior articular process on the cranial vertebral body. CONCLUSION: We macroscopically and histologically clarified the fibrous bands connecting the cervical nerve to the zygapophysial joint capsule. The fibrous bands may help clarify the pathology of cervical spondylotic radiculopathy associated with the zygapophysial joints as dynamic factors.Level of Evidence: N/A.

A morphological comparison of the extraforaminal ligament between the cervical and thoracic regions.

PURPOSE: The current study was conducted to clarify the morphology of the extraforaminal ligament (EFL) at the cervicothoracic junction and to compare the attachment of the EFL and the positional relation between the EFL and the spinal nerves, additionally to clarify the details within the connecting bundles at the cervicothoracic junction. MATERIALS AND METHODS: The EFLs from the 4th cervical to the 4th thoracic vertebrae were dissected in 56 sides of 28 Japanese cadavers (11 males, 17 females). The range of age was 62.0-99.0 years. In addition, connecting bundles were analyzed by histological examination. RESULTS: Ventral to the spinal nerve, the capsulotransverse ligament (CTL), transforaminal ligament (TFL) and the ligament between the 7th cervical vertebra and the 1st rib were attached to the transverse process and rib. The EFL ventral to the 1st thoracic nerve was not observed in all sides. Dorsal to the spinal nerve, the anterior part of the superior costotransverse ligament (ASCL) and the ligament homologous to the ASCL were attached to the transverse process and rib. The superior radiating ligament (SRL) and the ligament homologous to the SRL were identified. The connecting bundles identified between the 7th cervical and the 1st thoracic nerve were histologically confirmed to consist of nerves and vessels. CONCLUSIONS: The EFLs at the cervicothoracic junction were found to be homologous. The connecting bundles were observed between the 7th cervical and the 1st thoracic nerve. Interestingly, the 1st thoracic level alone might be a unique level at the cervicothoracic junction.