Type 1a olecranon fractures typically occur in neonates. The fracture is a true fracture through the physeal cartilage, separating the apophysis from the body of the olecranon. The degree of displacement will vary from a barely perceptible shifting in the position of the apophysis to complete avulsion with marked displacement.
Radiographic example of a widely displaced fragment (red arrow). It is important to recognize the separate center of ossification of the medial epicondyle of the humerus (yellow arrow) and its anatomic relationship to the olecranon apophysis (solid arrow).
Example of a minimally displaced fracture. In the radiograph on the right, note the slight cranial displacement of the olecranon apophysis when compared to the normal, opposite limb in the radiograph shown on the left.
The patient usually presents with severe lameness. If the fracture is displaced a dropped elbow stance is also evident. There will be varying degrees of soft-tissue swelling in the region of the elbow. These fractures are usually closed.