- FIGURE 2: the six ossification centres around the elbow joint
- Four of these are in the distal humerus, one is in the radius, and one is in the ulna
These all appear at different ages (usually but not always at 1-3-5-7-9-11 years) and fuse to adjacent bones at various ages; however, they usually appear in a specific sequence, or C-R-I-T-O-E:
- Radial head
- Internal (medial) epicondyle
- External (lateral) epicondyle
This helps identify if a potential abnormality is an avulsion fragment or a normal ossification centre.