Understanding Basics of Spine Surgery: Anatomy and Terminology

Before heading out for spine surgery, you must know its basic anatomy and terminology that might help you to get through the surgery easily. The human spine is a complex structure that unites both neurological and musculoskeletal elements. So, understanding the basics of spinal fixation surgery, its anatomy, terminology, and procedure can make the coding process easier. Let’s understand more in detail. Keep on reading.

Anatomy of the Spine

The spinal cord is divided into 31 pairs of peripheral nerves. Spinal meninges, which are not generally attached to the vertebrae of the spinal column, provide the majority of protection. The epidural space, which surrounds the spinal cord and functions as a cushion that separates them.

The first vertebra, C1, is commonly referred to as the atlas. The axes (C1 and C2) create a pivot joint that allows the head to move up and down as well as rotate from side to side. The vertebrae from C3 to L5 all have the similar form, with a front-facing body (corpus) and processes extending to the lateral and posterior sides.

The intervertebral space, also known as the interspace, is the space between two vertebral bodies that contain an intervertebral disc. On the other hand, the nucleus pulposus is a gelatinous material that is surrounded by an outer fibrocartilage ring. When the vertebrae move, the disc acts as a shock absorber. The neuroforamen is a lateral aperture formed by the intersection of two vertebrae through which the spinal nerves escape the spinal cord.

Spinal surgery anatomy includes the spinal cord and peripheral nerves, spinal meninges, spinal canal, and spinal column. The vertebral portions of the spinal column are the cervical, thoracic, lumbar, and sacral coccygeal. When stacked on top of one another, the intervertebral foramen of each vertebra line up to form a canal that supports the spinal cord.

Additional Terms and Definitions

Arthrodesis 

Arthrodesis, often known as fusion, is the procedure of fusing the pieces of a joint together to form a non-movable structure. There are several methods for fusing the intervertebral joints. After structural problems with the spine are addressed, such as nerve root and spinal cord decompression or removal of a herniated intervertebral disc, the treated portion of the spinal column is generally joined using interbody fusion devices or bone transplants.

Bone dowels and synthetic or metal cages, are known as interbody fusion devices that are being used to replace missing intervertebral discs. They are tapered from a bigger anterior edge to a smaller posterior edge to fit into the intervertebral area into which they will be implanted. To stimulate bone formation into the device, these devices are filled with crushed, or "morselized," bone matter. 

The posterior sections of the vertebrae (lamina and other spinous processes) are often removed during spinal surgery utilizing a posterior approach to get access to the spinal column and the anterior portion (body) of the vertebrae. The spine is typically not strong enough to support the weight of the body above the location after the treatment. As a result, structural bone grafts may be employed to fill any gaps that remain after the removal of vertebral material. 

Spinal Stabilization

Spinal instrumentation is frequently used to preserve the right curvature of the spine and to offer rapid stability. The type of instrumentation utilized is determined by the technique conducted. Moreover, the location of the procedure inside the spine, and the route get employed to obtain access to the spinal column. For instance- Procedures on the anterior region of the cervical spine is frequently necessitated the anterior insertion of a metal plate that spans the vertebrae in order to preserve the height and keep it stable. In contrast, procedures on the posterior region of the lumbar vertebrae are usually stabilized using segmental or non-segmental spinal instrumentation, such as rods and screws.

Whereas, the segmental instrumentation helps to support the spine by attaching to each fused segment individually. At each section, screws secure the bent rod. Non-segmental instrumentation, on the other hand, does not attach to each level. A hook is placed over a spinous process at the top of the bent rod, and a pedicle screw is used at the bottom. Rods are often put on both sides of the spinous process in both segmental and non-segmental instrumentation to provide stability.