Clavicle fracture
A clavicle fracture is a bone fracture in the clavicle, or collarbone.

# Frequency
Clavicle fractures involve approximately 5% of all fractures seen in hospital emergency admissions.  Clavicles are the most common broken bone in the human body.  It is most often fractured in the middle third of its length.  Children and
infants are particularly prone to it.  Newborns often present clavicle fractures following a difficult delivery.
After fracture of the clavicle, the sternocleidomastoid muscle elevates the proximal fragment of the bone. The trapezius muscle is unable to hold up the distal fragment owing to the weight of the upper limb, and thus the shoulder droops. The adductor muscles of the arm, such as the pectoralis major, may pull the distal fragment medially causing the bone fragments to override.

## History
Hippocrates, 4th century BC:
- When, then, a  fracture has recently taken place, the patients attach much importance to it, as supposing the mischief greater than it really is, and the physicians bestow great pains in order that it may be properly bandaged; but in a little time the patients, having no pain, nor finding any impediment to their walking or eating, become negligent; and the physicians finding they cannot make the parts look well, take themselves off, and are not sorry at the neglect of the patient, and in the meantime the callus is quickly formed. 
The management of skeletal injuries in ancient Egypt  Collar bone:
- If thou examinest a man having a break in his collar bone and shouldst thou find his collar bone short and separated from its fellow, I will treat. Place him prostrate on his back with something folded between his shoulder blades; thou shouldst spread out with his two shoulders to stretch apart his collar bone until the break falls in its place. 

# Symptoms
- Patient often reports a fall onto an outstretched upper extremity, a fall onto a shoulder, or direct clavicular trauma.
- Pain, particularly with upper extremity movement
- Swelling
- Often, after the swelling has subsided, the fracture can be felt through the skin.
- Sharp pain when any movement is made.
- Referred pain:  dull to extreme ache in and around clavicle area, including surrounding muscles.
- Possible nausea, dizziness, and/or spotty vision due to extreme pain

# Treatment
Treatment usually involves resting the affected extremity and supporting the arm with the use of a sling.  In older practice, a figure-8 brace was used, designed to immobilize and retract the shoulder, maintaining symmetric positioning to facilitate healing.  More recent clinical studies have shown that the outcomes of this method were not measurably different from simple sling support, and due to the movement difficulties caused to the patient, this method has mostly lapsed. Current practice is generally to provide a sling, and pain relief, and to allow the bone to heal itself, monitoring progress with X-rays every week or few weeks.  Surgery is employed in 5-10% of cases.
More than 90% of clavicle fractures are successfully healed by non-operative treatment. The surgery is indicated when one or more of the following conditions presents.
- Comminution with separation (multiple piece)
- Significant Foreshortening of the clavicle (indicated by shoulder forward).
- Skin penetration (Open Fracture).
- Clearly associated nervous and vascular trauma (Brachial Plexus or Supra Clavicular Nerves).
- Non Union after several months (36 months, typically)
- Distal Third Fractures which interfere with normal function of the ACJ (Acriomio Clavicular Joint).
A discontinuity in the bone shape often results from a clavicular fracture, visible through the skin, if not treated with surgery.  Surgical procedure will often call for ORIF (Open Reduction Interanal  Fixation) where an anatomically shaped titanium or steel plate is affixed along the superior aspect of the bone via several screws. In some cases the plate may be removed after healing, but this is very rarely required (based on nerve interaction or tissue aggavation), and typically considered an elective procedure.  Typical surgical complications are infection, neurological symptoms distal the incision (sometimes to the extremity), and non-union requiring re-plating.

# Post Surgical Healing
Healing time varies based on age, health, complexity and location of the break as well as the bone displacement.  For adults, a minimum of 34 weeks of sling immobilization is normally employed to allow initial bone and soft tissue healing, teenagers require slightly less, children can often achieve the same level in two weeks.  During this period, patients may remove the sling to practice passive pendulum ROM exercises to reduce atrophy in the elbow and shoulder, but they are minimized to 15-20 degrees off vertical.
The immobilization is followed by a theraputic regimen of passive exercises, and later of active exercises.  Full radiological union is typically achieved in 16 weeks for adult surgical patients, and shorter times are achieved by teenagers and young children.  In patients who participated in prescribed physical therapy, 85-100% mobility returned in 69 months, with full strength returning in 912 months.
More details can be found in the following studies: