What is a fracture of the dens?
A fracture of the odontoid bone (also called the dens), is an upward extension of C2 cervical vertebrae (i.e., axis) up into the C1 cervical vertebrae (i.e., atlas) and is held in place partially by the alar, apical and transverse ligaments.
Is the dens on C2?
The odontoid process, or dens, is a superior projecting bony element from the second cervical vertebrae (C2, or the axis). The first cervical vertebrae (atlas) rotates around the odontoid process to provide the largest single component of lateral rotation of the cervical spine.
What is the purpose of the dens?
It is a blunt tooth–like process that projects upward. It is also referred to as the ‘dens’ (Latin for ‘tooth’) or odontoid process. The dens provides a type of pivot and collar allowing the head and atlas to rotate around the dens.
Where is the dens bone?
The odontoid process, also known as the dens, is an upward projectile of bone that arises from the front part of the center of the axis vertebra. (The axis is the 2nd highest spinal bone.) The atlas is the first bone of your neck; it sits on top of the axis. (The skull sits on top of the atlas.)
What are the dens?
The odontoid process, also known as the dens, is an upward projectile of bone that arises from the front part of the center of the axis vertebra. This arrangement allows for a lot of freedom of motion between the combination of the head, first vertebra (atlas), and 2nd vertebra (axis).
What age does the dens fuse?
The odontoid process forms in utero from two separate ossification centers that fuse in the midline by the 7th fetal month. A secondary ossification center appears at the apex of the odontoid process (os terminale) between 3 and 6 years of age and fuses by age 12 years.
Is Odontoid fracture serious?
The odontoid process, also called the dens, is a protuberance of the axis. Life-threatening fractures can occur as a result of forces acting on this anatomical structure due to its proximity to the spinal cord and brainstem.
What is dens in neck?
Description. The odontoid process (also dens or odontoid peg) is a protuberance (process or projection) of the Axis (second cervical vertebra). It exhibits a slight constriction or neck, where it joins the main body of the vertebra.
What does the dens develop from?
Developmentally, the tip or apex of the dens is derived from a distinct secondary ossification center (cuneiform cartilage), whereas the remainder of the dens arises from laterally located primary ossification centers (Figure 5) [1, 14]. Schematic of ossification centers of the C2 vertebra.
Can a type 2 dens fracture be treated?
[Type 2 dens fracture in the elderly and therapy-linked mortality : Conservative or operative treatment] Fractures of the odontoid process pose a far-reaching danger for elderly patients. A balanced assessment of the general condition should be carried out at the beginning of treatment of these patients.
Where does a type II odontoid fracture occur?
A type II odontoid fracture is a break that occurs through a specific part of C2, the second bone in the neck. Bones of the spine are called vertebrae. The bone involved in odontoid fracture is the second vertebra, C2, high up in the neck.
What’s the difference between a type 2 and a Type 3 fracture?
Its due to an avulsion of a ligament called the alar ligament (an avulsion means the ligament is ripped off the bone and actually pulls part of the bone off with it). A type 2 fracture is a break at the base of the dens, and a type 3 fracture is when the break goes into the main portion of the second vertebre.
Which is the most common type of physeal fracture?
Salter-Harris type II fracture. Salter-Harris type II fractures are the most common type of physeal fractures that occur in children. There is a fracture that extends through the physis and into a portion of the metaphysis. A triangular metaphyseal fragment, otherwise known as the Thurston Holland fragment, will be left intact.