Joints and ligaments · Head and neck
Cricothyroid membrane !
The cricothyroid membrane is the soft gap just below the Adam's apple; it is the site for an emergency airway when the throat is blocked higher up.
Official name: Median cricothyroid ligament
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What it is
The soft gap between the thyroid and cricoid cartilages at the front of the neck.
What it does
The site for an emergency airway (cricothyrotomy) when the throat is blocked above.
Key facts
- Attaches
- Lower border of the thyroid cartilage to the upper border of the cricoid arch
- Function
- Closes the gap at the front of the larynx; emergency airway site (cricothyrotomy)
Relations
- Superficial
- Skin, subcutaneous fat and investing fascia; sometimes a pyramidal lobe of the thyroid gland or communicating anterior jugular veins
- Deep
- Subglottic airway, just below the vocal folds
- Lateral
- Cricothyroid muscles and, further out, the lobes of the thyroid gland
- Above
- Thyroid cartilage; the vocal folds lie inside the larynx a little above its upper border
How to find it
Laryngeal handshake: with the neck extended, thumb and middle finger steady the larynx from the hyoid bone down, and the index finger slides from the thyroid notch over the prominence into the dip above the cricoid. In obese or swollen necks ultrasound can mark it beforehand.
On imaging
Midline sagittal ultrasound shows the thyroid and cricoid cartilages as dark (hypoechoic) blocks with the bright air–mucosa line between them; used to mark the membrane before an expected difficult airway.
Common problems
- When the airway is blocked above the larynx and other methods fail, it is the emergency entry point.
How it is diagnosed
Felt as the soft dip below the Adam's apple.
Treatment
- Emergency cricothyrotomy by trained staff; later a formal tracheostomy.
Clinical notes
- The incision is placed in its lower part, near the cricoid, because the cricothyroid branches of the superior thyroid arteries usually cross its upper part
- In young children a needle technique is usually preferred, because the membrane is small and the cricoid is easily damaged
- Also a route for injecting local anaesthetic into the trachea for awake airway procedures and for retrograde intubation
- A surgical cricothyroidotomy is usually converted to a formal tracheostomy if a long-term airway is needed, to lower the risk of subglottic stenosis
Anatomical variants
- A pyramidal lobe of the thyroid gland, a remnant of the thyroglossal duct, may run up in front of it, usually a little to one side of the midline
Related conditions
Test yourself
Think of the answer, then tap the question to see it.
Why is the cricothyroid membrane the site of an emergency surgical airway in a can't-intubate, can't-oxygenate situation?
It lies close to the skin, has few vessels and is below the vocal folds.
How is the cricothyroid membrane located with the laryngeal handshake?
Steadying the larynx from the hyoid down, the index finger slides from the thyroid notch over the prominence into the dip above the cricoid arch.
Why is the cricothyroidotomy incision placed in the lower part of the cricothyroid membrane?
The cricothyroid branches of the superior thyroid arteries usually cross its upper part.
Which technique is usually preferred through the cricothyroid membrane in young children, and why?
A needle technique, because the membrane is small and the cricoid is easily damaged.
Educational information, not medical advice. For any symptom, see a health professional.
Its names
- Official Latin (TA2)
- ligamentum cricothyreoideum medianum TA2 1662
- Official Spanish (DeCS)
- Ligamento cricotiroideo medio
- English (TA2)
- Median cricothyroid ligament
- Also called
- cricothyroid ligament · ligamentum cricothyreoideum · ligamentum cricothyreoideum medium · pars libera coni elastici
Related
Sources: Terminologia Anatomica (TA2); Anatomy, Head and Neck: Larynx; Anatomy, Head and Neck: Larynx Cartilage.
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Representative model, for educational purposes only.
