Cervical Facet Dislocations & Fractures
ANATOMY OF THE SPINE
The human spine is formed by individual vertebrae and connective tissue discs in between. The vertebrae form the spinal canal. There are seven cervical, twelve thoracic, and five lumbar vertebrae. The intervertebral discs are the link between the individual vertebral bodies.
Normal anatomy of the spine. Longitudinal section and cross sections through the cervical, thoracic and lumbar spine.
The little joints that link the vertebrae together are known as facet joints. They help to stabilize the spine and, together with the intervertebral discs, allow a certain degree of mobility of the spinal cord. The spinal canal should be wide enough to allow nerve roots to float freely in cerebrospinal fluid.
The front border of the spinal canal is built by the vertebral bodies and intervertebral discs, the side by the intervertebral joints (facets) and back by the ligamentum flavum (yellow band) and vertebral arches. Discs consist of an outer fibrous ring (annulus fibrosus), which surrounds an inner gel-like center (nucleus pulposus).
The spinal cord and nerve roots lie within the spinal canal. The spinal cord extends downwards approx. to the 1st lumbar vertebra. Below, only nerve roots are present in the spinal canal. At the level of the intervertebral disc the nerve roots pass through the neural root foramina to exit the spinal canal. The spinal cord and nerve roots conduct electric-like signals from the skin and joints to the brain, and process of movement is initiated from the brain to the muscles.
Facet dislocation is an abnormal separation in the intervertebral joints (facets) leading in an anterior slip of one vertebral body on another. It usually results from a forced flexion and sometimes rotation of the cervical spine. Facet dislocation may occur on one (unilateral) or both (bilateral) facets connecting two vertebrae. It may occur to varying degrees: 1) subluxation - a ligamentous injury leading to a partial uncovering of facet joint surfaces or 2) locked facets - displacement of the inferior articular process of the upper vertebrae over the superior articular process of the vertebra below. Resulting in a locked in the position and lack of contact between the facet joint surfaces.
Facet fractures are a result of a traumatic hyperextension combined with lateral bending/rotation. They are often associated with an intervertebral disc disruption (PMID: 26516667
CAUSE OF SYMPTOMS
Acute compression of the cervical spinal cord
Cervical vertebral fracture
SYMPTOMS AND SIGNS
Тingling, numbness, pain or weakness in one hand. The pain usually starts in the neck.
In rare cases, total or partial paralysis of the hands/feet and insensitivity from the neck down.
Pain and stiffness in the neck
THE DIAGNOSIS IS BASED ON Medical history Clinical exam Computer tomography Magnetic resonance imaging (MRI)
additionally you may have to do: Digital subtraction angiography Functional (dynamic) radiographs
The treatment may be non-surgical or surgical.
Non-surgical treatment may include Nonsteroidal anti-inflammatory drugs
Fractures without significant dislocation, spondylolisthesis or kyphosis - stiff collar for 8-12 weeks
WHEN SHOULD AN OPERATION BE PERFORMED?
In most cases emergency surgery is required
WHAT IS THE GOAL OF SURGERY?
To release the compressed nerve roots and/or spinal cord
To restore the protective function of the spine
HOW IS SURGERY PERFORMED?
Open or closed reduction (restauration of aligment)
Anterior cervical decompression and fusion
WHICH OTHER DISEASES SHOULD BE EXCLUDED (DIFFERENTIAL DIAGNOSIS)? Other fractures of the spine