- serves as protector of brachial plexus
- acts as a strut which provides th only bony connection between upper limb and the thorax.
- embryology:
- first bone to ossify
- undergoes intra-membranous ossification w/o going thru prior enchondral stage;
- later in adolescence, secondary enchondral ossification does occur at both its ends;
- in adolescents, usually a single ossification center develops at medial end of the clavicle, fusing with the shaft by age 25;
- occassionally, an ossification center may develop at the acromion process (os acromiale), and these should not be mistaken for fractures;
- references:
- The embryology of the clavicle.
- Reflections upon the aetiology of congenital pseudarthrosis of the clavicle. With a note on cranio-cleido dysostosis.
- Outcome of clavicular fracture in 89 patients.
- The mechanism of clavicular fracture. A clinical and biomechanical analysis.
- Fracture Classification:
- frx of middle 1/3 (group I)
- most common clavicular frx in both adults and children (80%);
- frx usually occur in mid third region & have upward displacement of medial frag produced by sternocleidomastoid muscle.
- lateral fragment is pulled downward by wt of limb;
- frx of distal 1/3 (group II)
- account for 10-15% of clavicle frx;
- minimal displacement (type I)
- frx medial to CC ligaments (type II)
- articular surface fractures (type III)
- frx of medial 1/3 (group III):
- account for 5% of clavicular frx;
- Fractures of the medial end of the clavicle.
- Edwin Smith Papyrus: A Fracture of the Clavicle -
- examination: if thou examinest a man having a break in his collar-bone (and) thou shouldst find his collar-bone short and separated from its fellow.
- diagnosis: thou shouldst say concerning him : "One having a break in his collar-bone. An ailment which I will treat."
- treatment: thou shouldst place him prostrate on back, with something folded between his two shoulder-blades; thou shouldst spread out with his two
shoulders in order to stretch apart his collar-bone until that break falls into its place. thou shouldst make for him two splints of linen, (and) thou
shouldst apply one of them both on the inside of his upper arm. thou shouldst bind it with yarn, (and) treat it afterward with honey every day, until he recovers.