Clavicle fractures

Incidence = 4% of all fractures (Nordqvist & Petersson, 1994). Direct blow 94% cases.

Anatomy -  Middle 1/3 changes from prism to flat shape. Weakest point. Supraclavicular nn. cross it. Ulnar n crosses 1st rib under prox 1/3 clavicle. Clavicle anchored to scapula by CC and AC ligaments, and to trunk by SC and CC ligaments.

Function – osseous strut, maintaining width of shoulder. Protects NV structures and assists respiration with its ligamentous attachment to 1st rib and sternum. Angles 30 deg up and 35 deg back and rotates 50 deg on its axis when arm in full abduction.

CLASSIFICATIONS

1. Allman (1967):

Classified according to location- 

• Group 1 = Midshaft fractures (80%)
  o 1A - undisplaced
  o 1B - displaced
  o 1C - comminuted
  
• Group 2 = lateral-end fractures (15%) subclassified  (Neer 1984) in relation to CC ligaments:
  o Type 1 -minimal displacement, # usually between trapezoid and conoid.
  o Type 2 – medial to one or both CC – displaced #
  o Type 3 – intra-artic ACJ #  with ligamentous rupture. (lat to CC)
  
• Group 3 = medial fractures (5%)