A:

The bones of the spine are called vertebrae. They have a shape that allows them to anchor the rest of the skeleton and protect the spinal cord and nearby nerves.

The vertebrae appear rectangular when viewed from the side. "Anterior wedging" means that the front edge of the rectangle is compressed (wedged). When viewed from the side, the shape looks more triangular.

The "mid-thoracic" vertebra is in the middle of the spine. It's located between the neck (cervical spine) and lower back (lumbar spine). It includes vertebrae in the chest and upper abdomen.

An x-ray, MRI or CT scan report might describe "anterior wedging of the mid-thoracic vertebral body." This means there is a compressed appearance of the front part of the body of the spinal bone in the middle of the spine.

The most common causes for anterior wedging of vertebrae include:

• Osteoporosis
  A weakened bone breaks (called a compression fracture), most often in the lower thoracic and lumbar spine
• Trauma
  From an accident or injury
• Scheuermann's disease
  A skeletal disease of unknown cause that most commonly affects adolescents
• Aging
  The "wear and tear" of aging may cause bone compression and wedging of vertebrae

The significance of anterior wedging of thoracic vertebrae depends on the cause, how many vertebrae are affected, whether it's new, and whether it's causing symptoms.