The clavicle bone which is generally called the collarbone is a long bone that is located horizontally in the human body. There are two clavicle bones on either side. And they are located at the root of the neck. It is in place in-between the sternum (breast bone) and the scapula (shoulder blade).
It is bone having an “s” shape. The clavicle is subcutaneous throughout its length and palpation can be along its length. In a lean person, one can see it clearly.
Functions of the clavicular bone in the human body
The clavicle is a crank-shaped cantilever that carries the scapula. Therefore, it enabling the upper limb to swing freely away from the trunk. Further, it helps in transmitting the weight from the upper limbs to the axial skeleton acting as the only bridge between the upper limbs and the axial skeleton. There are many important structures like that go under the clavicle. For example, arteries veins, and brachial plexus.
Also Read: Supracondylar Fracture of Humerus
Articulation points of the clavicle bone
The clavicle contains a medial end, a lateral end, and a shaft. The medial and lateral ends vary in shape.
• The medial end is enlarged. It articulates with two bones. Those are the clavicular notch which is on the manubrium sterni and the first costal cartilage.
• The lateral end is flattened. It articulates with the medial side of the acromion. Acromion is a small section extending anteriorly from the spine of the scapula.
• The shaft is a curved shape. It is curved forward (convex) in its medial two-third and curved back (concave) in its lateral one-third.
Muscular attachments of the clavicle bone
On the superior surface of the clavicle, there are four main muscular attachments.
- Medially it has two muscle attachments. Namely, they are, sternocleidomastoid muscle posteriorly and the pectoralis major muscle anteriorly.
- Laterally also it has two attachments. The trapezius muscle posteriorly and deltoid muscle anteriorly.
Similarly, on the inferior surface clavicle has attachments for muscles.
- Anteriorly there is attachment to the pectoralis major muscle clavicular head throughout its medial three-fifth.
- Posteriorly there is a small area for the attachment of the sternohyoid muscle.
- Along the inferior side of the intermediate two-fifths, there is a groove for the attachment of the subclavian.
- More laterally, on the inferior surface of the clavicle bone, there is an attachment for deltoid. And posterior to that it has an attachment for the trapezius.
Important structures associated with the clavicle.
More laterally the middle three-fifths of the clavicle bone curves in front of the trunks and divisions of the brachial plexus. Also, the third part of the subclavian artery lies below it.
There are few structures immediately behind and above the medial three-fifths. Namely, they are
- The thoracic-cervical trunk branches
- The suprascapular vessels
- The transverse cervical vessels.
Although these structures are closely in association with the clavicular bone, they are rarely getting into damage in a fracture.
Clavicle bone fracture
Clavicular bone fracture is mostly due to falls on an outstretched hand. The most common site of fracture is the middle of the shaft. A person with a fracture of the clavicle bone always presents by supporting their fractured sidearm with the other arm. In this, the most appropriate measures of management are with immobilizing with a splint. Whereas surgery is not for treatment since it spontaneously heals over months of resting. However, it is important to check if the movements of the upper limbs seem to be impair or not. Because a lot of important neurovascular structures are in close association with the clavicle bone.
A person suffering from clavicle bone fracture may experience great pain while moving their shoulder or arm. There might be swelling or tenderness in the fractured area. Similarly, the shoulder might sag in the anterior or interior direction.
The treatment of the clavicle bone fracture can be by a surgical or non-surgical way depending on the condition of the fracture.
The non-surgical method is applicable if the fractures still line up correctly. In this method, a simple arm sling keeps the pieces in line and heals naturally in course of time.
The surgical method is applicable if the fracture pieces are not in alignment.
In this method, the clavicle fracture pieces are screwed to a metal plate which helps them to keep it in a place and helps to heal.
The clavicle is called the beauty bone of the body and it is called beauty bone due to its prominent location in our body which gives alignment to a person’s body.
The clavicle is the weakest bone because it is a thin bone and runs horizontally between the breastbone and shoulder blade. Since is the weakest bone it is more prone to fractures.
The weakest part of the clavicle is the middle third segment of the clavicle and this part is also more prone to fractures.