The C7-T1 spinal segment, sometimes referred to as the cervicothoracic junction, is located at the very bottom of the neck.
This spinal segment is unique because it is the point of transition from the highly flexible neck to the nearly completely inflexible upper back. It is also the point where the lordosis, or backward curvature of the cervical spine, reverses into kyphosis, or forward curvature, of the upper back.
The C8 nerve root exits the spinal cord at the C7-T1 spinal segment. If the C8 nerve becomes compressed or irritated for any reason, then C8 radiculopathy will occur. Symptoms can include pain, weakness, numbness, or tingling radiating down the lower shoulder and back of the arm and forearm, going into the pinky and ring finger. Cervical radiculopathy is usually only on one side of the body, but if both C8 nerve roots are involved, then it can be felt on both sides.
Compared to the spinal segments directly above it at C6-C7 and C5-C6, radiculopathy is less common at the C7-T1 level. One reason is because at the cervical spinal levels of C5-C6 and C6-C7, the disc is located at about the same height as the nerve roots; but at C7-T1, the C8 nerve roots are located higher than the disc.1 So there is less chance for the disc to compress the C8 nerve root.
Common Causes of C7-T1 pain
Some of the conditions that can cause symptoms at the C7-T1 level include the following:
C7-T1 degenerative disc disease
If the disc between the C7 and T1 vertebrae degenerates enough it can become a source of pain. The pain can be from the disc itself or perhaps from irritation and/or inflammation associated from the collapsing disc.
C7-T1 disc herniation
While disc herniation at the C7-T1 level is not that common, it is possible for the disc to herniate if a tear in its fibrous outer layer occurs, allowing a portion of the gelatinous inner layer to leak out of the disc. This inner substance of the disc contains proteins that cause inflammation when they come into contact with nerves and soft tissues.
With less bending and fewer joints than the cervical spinal segments directly above it, the C7-T1 spinal segment is less likely to be affected by osteoarthritis. However, it can still happen through natural wear and tear of the facet joints or be accelerated by an injury.
C7-T1 spinal stenosis with myelopathy
Spinal stenosis at this level is possible if the spinal canal narrows. If this narrowing causes the spinal cord to become affected, then myelopathy and its neurological symptoms may be diagnosed.
Myelopathy indicates that the spinal cord’s health is in jeopardy. Without treatment, a permanent spinal cord injury could develop. If a spinal cord injury happens at the C7-T1 spinal segment, then some or most of the ability to feel sensations beneath the neck could be lost; and it is possible for full or partial paralysis of the legs, core muscles (trunk), and fingers to develop.
C7-T1 foraminal stenosis
The C8 nerve can become compressed at the foramen—a bony hole where the nerve root branches off from the spinal cord and exits the spinal canal—if the foramen narrows enough due to bone overgrowth.
Less Common Causes of C7-T1 Pain
This rare condition is more likely to occur in the lower back than the neck. However, it can still happen at the C7-T1 spinal segment if the C7 vertebra slips forward over the T1 vertebra. Some people are more genetically predisposed to having spondylolisthesis, but it can also happen due to trauma, such as from a sports injury that affects the neck and/or upper back.
An infection in a cervical spinal segment is rare. It is also possible for the C7-T1 level to become infected secondary to a lung infection.
A tumor growing at the C7-T1 level is rare, but when it happens, it can be painful and might cause cervical radiculopathy by pressing against the C8 nerve.
A broken bone at the C7-T1 level can cause pain and other symptoms, especially if the C8 nerve root becomes irritated and/or if the spinal cord is affected by the fracture.
Most types of pain that originate at the C7-T1 level can be treated with nonsurgical methods. As a general rule, if nonsurgical methods prove to be insufficient after 3 to 6 months and the pain is severe, then surgery can be recommended.
The C7 and T1 vertebrae have different shapes compared to the cervical vertebrae above it, making this spinal segment more difficult for surgeons to access through the front for the following reasons:
- Deeper in the body
- Surrounded by more bone
- Near critical neurovascular bundles2
As such, the surgical options at C7-T1 tend to be fewer and more complex compared to surgical options typically commonly done higher in the neck, such as an ACDF.
- Cramer GD, Darby SA. The cervical region. Clinical Anatomy of the Spine, Spinal Cord, and ANS. 3rd ed. 2014:151.
- Scheer JK, Deviren V, Lee SH, Ames C. Posterior cervicothoracic osteotomy. In: Vaccaro A, Eck JC. Surgical Atlas of Spinal Operations. 1st ed. New Dehli, India. Jaypee Brothers Medical Publishers. 2013:211-21.