We understand that researching options for spine surgery can be overwhelming. With this in mind, we do our best to ensure the language on our website is presented in a way that makes sense to a wide range of potential patients. To help with that process, we have included a glossary of key terms to make things even easier.

Anatomy of the Spine

The primary role of the spinal column is to support the mass of the body to keep its shape and to protect the spinal cord, nerves, and blood vessels from injury.

The bony anatomy of the spine is composed of 33 vertebrae that are classified into 5 regions that have unique forms and functions.

The cervical spine, also known as the neck, is comprised of seven vertebral bodies (C1-C7) that make up the uppermost part of the spine. These vertebrae connect the spine to the skull.

Key Characteristics:
Cervical vertebrae have transverse foramen (little “windows”) that contain and shelter the vertebral arteries and veins that run along your neck.

The thoracic spine is comprised of twelve vertebral bodies (T1-T12) that make up the mid-region of the spine. The firm attachment to the rib cage at each level of the thoracic spine provides stability and structural support and allows very little motion.

Key Characteristics:
The ribs attach to the thoracic vertebrae and protect the heart and lungs.

The part of the spine comprised of five vertebral bodies (L1-L5) that extend from the lower thoracic spine (chest) to the sacrum (bottom of the spine). The vertebral bodies are stacked on top of each other with a disc in between each one.

Key Characteristics:
The lumbar spine is responsible for bearing the weight of the body and helping to provide flexibility.

The sacral spine, or sacrum, is a fusion of 5 vertebrae in between your hips.

Key Characteristics:
Connects the spine to the hip bones (iliac)

Commonly referred to as the tailbone, the coccygeal spine, or coccyx, consists of 4 vertebrae.

Key Characteristics:
Believed to be a vestigial structure left over from evolution.

Patient Terminology

Orthopedic implants are devices surgically placed into the body designed to restore function by replacing or reinforcing a damaged structure until spinal fusion occurs.

Many imaging techniques are used by doctors to get an inside view of the spine including x-rays, MRIs, and CT scans.

Normally, the spine has three gentle front-to-back curves. The cervical and lumbar spine has an inward curve called lordosis. The thoracic (middle) spine has an outward curve called kyphosis. Usually, these curves work in harmony to keep the body’s center of gravity aligned over the hips and pelvis.

However, if one of those curves becomes either too pronounced or too flat, which can be different for each person, the spine will be out of balance back-to-front. This is sagittal imbalance.

Sagittal alignment been found to correlate to a higher quality of life and is determined by taking measurements of the spine known in the medical community as spinopelvic parameters.



Deformities of the spine are classified by how the spine deviates from normal alignment. For example, scoliosis is an axial deformity of the spine shown below.

Spinal fusion involves techniques involved to mimic the normal healing process of broken bones to fuse together vertebrae so they heal into a single solid bone. Fusion surgeries are done to help with many spinal pathologies and there are many methods to achieve fusion.

Everyone has a unique curvature of the spine that can be scientifically measured. Spinopelvic parameters is a blanket term for these measurements, which include Pelvic Incidence (PI), Lumbar Lordosis (LL), Sagittal Vertical Axis (SVA), and much more.