Extraarticular 3-part, surgical neck and tuberosity, no impaction

These fractures are bifocal fractures, involving the surgical neck and one tuberosity. Neither fracture line involves the articular surface, and the metaphyseal (surgical neck) component is not impacted.

These fractures are unstable because the metaphysis is not impacted. The periosteum is quite often ruptured. Additionally, there can also be a comminution in the metaphyseal zone.

These fractures come with or without rotational displacement of the epiphyseal fragment. Either the greater or the lesser tuberosity may be displaced.

Due to either instability and/or irreducibility, they often require open reduction and internal fixation.

This subgroup shows no metaphyseal impaction and no rotational displacement of the epiphyseal fragment. The greater tuberosity is separated and displaced. This fracture type is suspicious for a pre-existing rupture of the subscapularis tendon.

These fractures show a rotational displacement due to muscle tension on the adjacent, intact tuberosity. Either the greater or the lesser tuberosity is displaced. A fractured lesser tuberosity may not be easily be visualized in the x-ray, except in the axillary lateral view. A CT scan is therefore very helpful and recommended.

X-rays by courtesy of B Ockert, LMU Munich, Germany.

In these fractures the metaphyseal fracture zone is displaced and multifragmentary. It is combined with a fracture of one of the tuberosities. Due to muscle pull of the adjacent, intact tuberosity, a typical rotational component of the epiphyseal fragment can be seen – internal rotation with a greater tuberosity fracture or external rotation with a lesser tuberosity fracture.

X-rays by courtesy of B Ockert, LMU Munich, Germany.