This is a rare injury.
The most common mechanism of injury is a deceleration stress superimposed on a contracted triceps muscle (a fall onto the outstretched hand)
On Clinical Examination, features
usually include pain, swelling and a palpable depression
just proximal to the olecranon and a posterior ecchymosis.
Passive flexion and passive extension of the elbow are
painful.
Resisted extension of the elbow is painful and weak.
In about 80% of the patients, flecks of osseous material are visible on the lateral radiograph.