Capitellum Fractures
Definition
- Fracture of the capitellum
Incidence
-
Rare injuries
Aetiology
- Mechanism of injury is loading through radius, followed by shearing
- 20% are accompanied by radial head fractures.
- May be associated with DRUJ injury, interosseous membrane/ligament injury and/or MCL injury
Anatomy
Classification
| Type | Description |
|---|---|
| I | Complete fracture of capitellum with large bone fragment (Hahn-Steinthal I) |
| II | Thin osteochondral wafer of capitellum (Kocher-Lorenz) |
| III | Comminuted capitellar fracture |
| IV | Fracture line extends into the trochlea past the lateral trochlear ridge (Hahn-Steinthal II) |
Pathology
History
Examination
Investigations
- Plain X-rays including radial head/capitellum views
- CT scanning with coronal & sagittal reconstructions
Treatment
- Displaced fragments need ORIF
- Particularly important to reconstruct the capitellum if there is an associated injury to interosseous membrane, MCL or radial head, otherwise late instability may develop
Complications
- Loss of motion
- Ostenecrosis
Prognosis
- Loss of some elbow motion is common, & is usually greater with acute excision than ORIF
- Osteonecrosis of the capitellum is rare & usually without consequence