Die-punch injury to the paediatric olecranon fossa

A fifteen-year-old boy with an immature skeleton presented to our department having sustained an axial loading-type injury to the elbow. X-ray revealed an unusual pattern of injury to the olecranon. The articular surface of the olecranon had a depression from axial loading of the trochlea of the humerus similar to a die-punch type intra-articular injury seen at the distal radius. A CT scan was arranged which confirmed a bony depression of the olecranon measuring up to 5 mm. Surgery was performed to restore congruency to the joint surface on the basis of this scan, but intra-operatively, we noticed articular cartilage depression of only 1–2 mm with no loose bodies in the joint. The joint surface was left as it was and the approach closed. Six months on from injury, the child was clinically and radiographically normal. We note that CT scan although useful may be misleading in this type of injury and that non-operative management gave an excellent outcome.