Cricoarytenoid joint

Cricoarytenoid joint refers to a pair of synovial joints in the larynx, playing a crucial role in the production of vocal sounds by controlling the tension and position of the vocal cords. These joints are located between the cricoid and arytenoid cartilages, allowing for the rotation and gliding of the arytenoid cartilages. This movement is essential for the opening, closing, and tension adjustment of the vocal cords, which in turn modulates voice pitch and volume.

Anatomy

The cricoarytenoid joint is formed by the articulation between the base of the arytenoid cartilage and the cricoid cartilage. The arytenoid cartilages are pyramid-shaped and located at the posterior aspect of the larynx. The cricoid cartilage, shaped like a signet ring, sits just below the thyroid cartilage and above the trachea. The joint capsule is reinforced by ligaments, including the posterior cricoarytenoid ligament, which provides stability to the joint.

Function

The primary function of the cricoarytenoid joint is to facilitate the movement of the vocal cords. This is achieved through two main movements:

• Rotation: This movement allows the vocal cords to be abducted (moved apart) or adducted (brought together), which is essential for phonation and breathing.
• Gliding: This movement adjusts the tension of the vocal cords, affecting the pitch of the sound produced.

These movements are controlled by various muscles, including the posterior cricoarytenoid muscle, which is the only muscle capable of abducting the vocal cords, and the lateral cricoarytenoid muscle, which adducts the vocal cords.

Clinical Significance

Dysfunction of the cricoarytenoid joint can lead to voice disorders, breathing difficulties, or both. Conditions such as cricoarytenoid arthritis, often seen in autoimmune diseases like rheumatoid arthritis, can cause pain and stiffness in the joint, leading to voice changes or difficulty in breathing. Laryngeal trauma or intubation can also result in cricoarytenoid joint dislocation or fixation.

Diagnosis and Treatment

Diagnosis of cricoarytenoid joint dysfunction typically involves a combination of patient history, physical examination, and imaging studies such as CT or MRI scans. Laryngoscopy can also be used to directly visualize the vocal cords and assess their movement.

Treatment depends on the underlying cause of the dysfunction. Options may include voice therapy, anti-inflammatory medications, or surgery in severe cases. Voice therapy is often the first line of treatment, focusing on techniques to reduce strain and improve vocal cord function.

See Also

• Larynx
• Vocal cords
• Rheumatoid arthritis
• Laryngoscopy