The clavicle connects the axial skeleton to the appendicular skeleton. It has a great deal of muscular attachment, and has a role in protecting the neurovasculature if the neck and thorax. It is considered a part of the borders off the thoracis inlet, and has articulations with the scapula and hence the upper limb. The clavicle is S shaped and articulates with the acromion process of the scapula laterally and the clavicular notch of the manubrium medially. It lies in front of the subclavian vein, and is attached to the first rub by the costoclavicular ligament and the subclavius muscle.
The clavicle begins the ossification forces during the 5th-6th gestational week, and is the last bone to complete ossification (around 20-25 years of age). It is an s shaped bone that articulates with the manubrium of the sternum via its rounded medial end, and with the acromion process of the scapula via its flat lateral end.
The shaft of the clavicle is divided into thirds. The anterior surface of the bone has a convex surface forwards, that gives rise to the pectoralis major muscle. The sternohyoid muscle inserts on the posterior surface of the clavicle. The superior surface of the clavicle is rough and bumpy, and is where the sternocleidomastoid muscle inserts. The Subclavius and costoclavicular ligament arise from the inferior surface of the bone, and insert onto the first rib below.
The deltoid muscle originates from the lateral third of the clavicle. The trapezius muscle originates from the posterior surface. The conoid and trapezoid ligaments are coracoclavicular ligaments (the conoid attaches more medially), which arise from the lateral part of the superior surface of the clavicle and attach to the coracoid process. The inferior aspect of the clavicle has a conoid tubercle and a trapezoid line, from which these ligaments arise and insert onto the coracoid process. The superior surface of the bone lies directly under the skin. The clavicle has no bone marrow, even though it is classified as a long bone.
Developmental precursor- Limb bud (lateral mesodermal mesenchyme)
The clavicle (also known as the collar bone) is an s shaped bone, that articulates with the acromion process of the scapula laterally and the clavicular notch of the manubrium medially. It lies in front of the subclavian vein, and is attached to the first rub by the costoclavicular ligament and the subclavius muscle.