Trapezoid ligament

A ligament in the shoulder girdle

The trapezoid ligament is a key component of the coracoclavicular ligament complex, which plays a crucial role in stabilizing the acromioclavicular joint of the shoulder. This ligament is one of two parts of the coracoclavicular ligament, the other being the conoid ligament.

Anatomy

The trapezoid ligament is a strong, fibrous band that extends from the coracoid process of the scapula to the clavicle. Specifically, it attaches to the trapezoid line on the inferior surface of the clavicle. The ligament is named for its trapezoidal shape, which is broader at the clavicular attachment and narrower at the coracoid process.

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Diagram showing the location of the trapezoid ligament in the shoulder.

Function

The primary function of the trapezoid ligament is to provide stability to the acromioclavicular joint by anchoring the clavicle to the scapula. It resists forces that would otherwise displace the clavicle superiorly or anteriorly. This ligament, along with the conoid ligament, helps maintain the alignment of the clavicle with the scapula, especially during movements of the shoulder.

Clinical Significance

Injuries to the trapezoid ligament are often associated with acromioclavicular joint dislocations, commonly referred to as shoulder separations. Such injuries can occur due to trauma, such as a fall directly onto the shoulder. Damage to the trapezoid ligament can lead to instability of the acromioclavicular joint, resulting in pain and limited range of motion.

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Illustration of a shoulder injury involving the acromioclavicular joint.

Surgical Considerations

In cases of severe injury, surgical intervention may be required to repair or reconstruct the trapezoid ligament. Surgical techniques often involve the use of grafts to restore the ligament's function and stabilize the joint. Post-surgical rehabilitation is crucial to regain full shoulder function.

Related Pages

• Acromioclavicular joint
• Coracoclavicular ligament
• Conoid ligament
• Shoulder anatomy