Executive Editor: Peter Trafton, Michael Baumgaertner

Authors: Peter Kloen, David Ring

Proximal forearm Anterior fracture dislocation

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Glossary

1 Introduction top

Complex fractures of the proximal ulna with anterior translation of the forearm with respect to the distal humerus are anterior (or trans-olecranon) fracture-dislocations of the elbow. The radial head is not fractured. The collateral ligaments are usually intact. When the coronoid is fractured, it is usually one large piece and is rarely fragmented.


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Principles

  • The radial head is not fractured.
  • The collateral ligaments are usually uninjured.
  • The key is restoration of the trochlear notch of the ulna by correct alignment of the coronoid and olecranon processes.
  • Metaphyseal and diaphyseal fragmentation can be bridged with a long plate.
  • Beware of substantial impaction in the depths of the trochlear notch. This may need a structural graft to prevent anterior subluxation of the forearm.

2 Approaches top

A posterior skin midline incision can be used to raise both medial and lateral skin flaps.

Further dissection can proceed medially or laterally. Alternatively, raise olecranon fracture fragment with the triceps as with an olecranon osteotomy.

The Boyd approach is used to access the radial head as well as the olecranon and proximal ulna.

3 Fixation top

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Sequence of repair

  1. Address coronoid fracture.
  2. Address impaction of the articular surface in the center of the trochlear notch.
  3. Realign and secure the olecranon fragment


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Coronoid repair

After mobilizing the olecranon process with the triceps, address the basilar coronoid fracture.


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Impaction of the articular surface in the center of the trochlear notch

Realign fracture fragments in the center of the trochlear notch to ensure that the trochlea does not settle and allow the forearm to subluxate anteriorly.

Sometimes a structural bone graft from the iliac crest is helpful.


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Repair the olecranon with a posterior plate

4 Final assessment top

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The MCL and LCL are usually intact. Fixation of the olecranon and coronoid should restore stability to the elbow.  Check the alignment of the radial head with the capitellum through a full arc of elbow flexion and extension and forearm rotation to be sure there is no ulnar malalignment.  Also, be sure there is no crepitation in the joint suggesting errant screws or persistent joint malalignment.

v2.0 2018-04-30