Clavicle Fracture

A clavicle fracture is a break in the collarbone, usually from a fall onto the shoulder, and most unite well without surgery.

Clavicle fractures account for around 2.6% to 4% of all fractures. The pattern is bimodal: young men injured in sport, cycling or road traffic collisions, and older adults after low-energy falls.

A small group needs urgent orthopaedic assessment, and some displaced fractures benefit from fixation after shared decision making.

The clavicle is an S-shaped strut linking the upper limb to the axial skeleton through the sternoclavicular joint (SCJ) medially and the acromioclavicular joint (ACJ) laterally. The Allman classification divides it into thirds:

• •Group I: middle third (around 80% of fractures)
• •Group II: lateral third (around 15%)
• •Group III: medial third (around 5%)

The middle third breaks most often because it is the narrowest part and has no overlying muscle or ligament to protect it.

In a displaced mid-shaft fracture, sternocleidomastoid pulls the medial fragment up and back, while the weight of the arm drags the lateral fragment down, giving the classic Z-deformity.

The Neer classification of lateral third fractures depends on the coracoclavicular (CC) ligaments and drives management (see Management). The Edinburgh (Robinson) classification is an alternative UK prognostic system.

The subclavian vessels and brachial plexus lie behind the clavicle, so high-energy injuries need a neurovascular check. Pneumothorax and an associated scapular fracture are less common associated injuries.