Lateral mass

Lateral mass refers to a significant anatomical structure found in the vertebral column, specifically within the cervical spine. It is a key component in the architecture of the cervical vertebrae, providing stability and support for the neck and head. The lateral mass is crucial for the articulation and motion of the cervical spine, as well as for protecting the spinal cord and its associated structures.

Anatomy

Each cervical vertebra consists of a vertebral body at the front, and a vertebral arch at the back, which together enclose the vertebral foramen, housing the spinal cord. The lateral masses are paired structures located on either side of the vertebral arch. They serve as the attachment sites for the facet joints, which are synovial joints connecting the vertebrae to each other, allowing for the flexibility and motion of the neck.

The lateral masses are connected by the pedicle, a short bony projection, to the vertebral body, and by the lamina, a thin bony plate, to the spinous process at the back of the vertebra. The superior and inferior surfaces of the lateral mass present articular facets, which articulate with the corresponding facets of the adjacent vertebrae, forming the facet joints.

Function

The primary function of the lateral mass is to provide structural support and stability to the cervical spine, while also facilitating its range of motion. The articulation of the lateral masses via the facet joints allows for movements such as flexion, extension, lateral flexion, and rotation of the neck.

Additionally, the lateral masses play a crucial role in protecting the spinal cord and the nerve roots that exit the spinal canal through the intervertebral foramina, openings formed between adjacent vertebrae. The integrity of the lateral masses is essential for maintaining the alignment of the cervical spine and preventing nerve compression or damage.

Clinical Significance

Injuries or abnormalities of the lateral masses can lead to instability of the cervical spine, pain, and neurological deficits due to compression of the spinal cord or nerve roots. Conditions such as fractures, arthritis, and spondylosis can affect the lateral masses, impacting their function and the overall health of the cervical spine.

Surgical interventions, such as lateral mass fixation, may be required to restore stability and alignment in cases of severe injury or degeneration. This procedure involves the placement of screws and rods to secure the lateral masses and facilitate the healing process.

Related Articles

• Cervical vertebrae
• Facet joint
• Spinal cord
• Vertebral column