Clavicle Bone Anatomy

Author: Kevin Kuschel MD

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The clavicle, or the collarbone, is an S-shaped bone that connects the trunk with the appendicular skeleton of the upper limb. Medially, the clavicle articulates with the sternum via the sternoclavicular joint, while laterally it articulates with the scapula through the acromioclavicular joint. These connections help transmit the force adequately from the upper limb to the trunk and overall coordination of the upper limb movements in respect to the trunk.

This article will discuss the anatomy of the clavicle, including its bony markings, as well as the muscles that attach to it.

Key points about the anatomy of the clavicle
Sternal endSternal articular surface for articulation with sternum;
Impression for costoclavicular ligament attachment
BodySubcutaneous and palpable superior surface. Groove for subclavius muscle attachment on the inferior surface.
Acromial endAcromial facet for articulation with scapula at AC joint.
Tuberosity for coracoclavicular ligament attachment (trapezoid line, conoid tubercle).
Muscle attachmentsDeltoid, trapezius, sternocleidomastoid, pectoralis major, sternohyoid and subclavius muscle


Anatomy of the clavicle (labeled diagram)
Anatomy of the clavicle (labeled illustrated diagram)
Anatomy of the clavicle (labeled diagrams)

The clavicle has a shape of a long bone, with two extremities and a shaft. It features two surfaces, superior and inferior. The medial end of clavicle articulates with the sternum, so it is called the sternal end. The sternal end features the sternal articular surface for the said joint. Besides, on its inferior surface, it shows a roughened area called the impression for costoclavicular ligament, that serves as the attachment of the same named ligament.

The lateral extremity articulates with the acromion of the scapula, and so is called the acromial end. It features the acromial facet for the AC (acromioclavicular) joint, as well as the tuberosity for coracoclavicular ligament on its inferior side. This tuberosity consists of the conoid tubercle which is continued by a prominent ridge called the trapezoid line.

Acromial facet
Sternal articular surface
Trapezoid line
Conoid tubercle
Groove for subclavius muscle
Impression for costoclavicular ligament
Bony landmarks on the clavicle

The shaft of the clavicle is between the two extremities and it is termed as the body of clavicle. The superior surface of the body is rather smooth. It is subcutaneous and palpable. The inferior surface features an elongated depression for the attachment of the subclavius muscle, called the groove for subclavius muscle.

Although being shaped as a long bone, the clavicle lacks the medullary cavity that is usually seen in long bones. Instead, its internal substance is composed of the spongy (trabecular) bone.

Muscles that attach to the clavicle

There are six muscles that attach to the clavicle: deltoid, trapezius, sternocleidomastoid, pectoralis major, sternohyoid and subclavius muscle. Their attachments are presented in the following diagram:

Muscle attachments on the clavicle (diagram)
Muscle attachments on the clavicle (illustrated diagram)
Muscle attachments on the clavicle (labeled diagrams)

Clavicle anatomy quiz

Anatomy of the clavicle quiz

Test your knowledge on the anatomy of the clavicle (collarbone)!


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