UCSD Musculoskeletal Radiology


MSK Classifications


Allman classification of clavicle fractures

GROUP I Middle third fractures (80%)


GROUP II Distal third fractures (15%)

  • Type I Minimally displaced / interligamentous
  • Type II Displaced fractures, fracture medial to the coracoclavicular ligaments
    • IIA Both ligaments (conoid and trapezoid) attached to the distal fragment
    • IIB Conoid torn, trapezoid attached to the distal fragment
  • Type III Fractures involving articular surface
  • Type IV intact coracoclavicular ligaments attached to periosteal sleeve plus proximal fragment displaced
  • Type V Comminuted

GROUP III Fracture of the proximal third (5%)

  • Type I Minimally displacement
  • Type II Displaced
  • Type III Intra-articular
  • Type IV Epiphyseal separation
  • Type V Comminuted