What is the role of the alar ligament?
Function. The function of the alar ligaments is to limit the amount of rotation of the head, and by their action on the dens of the axis, they attach the skull to the axis, the second cervical vertebra.
What movement does the alar ligament limit?
The alar ligaments are fibrous cords that attach to the dens bilaterally and insert on the base of the skull. They function to limit axial rotation and lateral bending on the contralateral side, and flexion secondarily [1-2].
What is alar ligament?
They are paired ligaments that are very strong and limit axial rotation and contralateral lateral flexion of the head. In conjunction with the transverse band of the cruciform ligament, they are the primary stabilizers of the atlantoaxial joint 2.
What is atlas and axis?
The atlas is the first cervical (neck) vertebra which is just under the head; it is named for Atlas, the Greek god who supported the world on his shoulders. The axis is the second cervical vertebra; it has what is called the odontoid process about which the atlas rotates. It allows the head turn from side to side.
What is alar fascia?
The alar fascia is a thin fibroareolar membrane separating the (anterior) true retropharyngeal space from the (posterior) danger space. It is the ventral component of the deep layer of the deep cervical fascia.
What do alar ligaments stabilize?
The alar ligaments (blue in the image to the left) come up from the dens and connect the C2 vertebra to the skull. The transverse ligament (red) acts as like a seat belt for the dens. These ligaments stabilize the upper neck when you look down, turn your head, or do both.
How many alar ligaments are there?
Each of the five ligaments with transverse bands displayed a large proportion of fibres traversing directly from occipital condyle to occipital condyle.
Where is the Alar?
The alar groove, which lies at the junction of the lower lateral crus (medially) and the alar lobule (laterally), is defined not as much by a muscular attachment between the perichondrium of the lower lateral cartilage and the vestibular mucosa as by a bulging in the fatty layer on one side of the groove (within the …
What makes C1 and C2 atypical?
C1 and C2 are considered atypical vertebrae because they have some distinguishing features compared to the rest of the cervical spine. C1 Vertebra (the atlas). The top vertebra, called the atlas, is the only cervical vertebra without a vertebral body. Instead, it is shaped more like a ring.
What is the purpose of the alar ligament test?
Alar Ligament Test. Contents. Purpose. To assess the integrity of the alar ligaments and thus upper cervical stability. Both the side-bending and rotation stress tests for the alar ligaments are based on preventing the inherent coupling of rotation and lateral flexion in the occipito-atlanto-axial complex.
How to diagnose calcification of the alar ligament?
Calcification of the alar ligament may be associated with neck and/or nuchal pain 1-4. Calcium pyrophosphate dihydrate (CPPD) and calcium hydroxyapatite (HAP) deposits are likely components of the calcification 2. CT scanning of C1/C2 is the best tool for the diagnosis of this condition 2 .
Which is more common alar or transverse ligaments?
In the case of the alar and transverse ligaments, the former type of ligament injury is much more common. This means that the upper neck bones become unstable and move around too much.
What to do if you have an alar ligament problem?
There may be clicking or popping and activity such as exercise or physical therapy usually makes the problem worse. Very specific upper cervical manipulation (i.e., by an experienced upper cervical chiropractor or high-level manual therapist) can provide temporary relief.