Mason initially classified fractures of the radial head at the elbow using a relative simple scheme. This was modified by Morrey to take into account associated soft tissue injuries.


Exclusion: compound fractures

Mason's Classification for Fractures of the Radial Head


fissure or marginal sector fractures without displacement


marginal sector fractures with displacement


comminuted fractures involving the entire head of the radius




• A marginal sector fractures involves a segment of the lateral segment of the radial head.

• A displaced marginal sector fracture may show separation of the fracture fragment, depression and/or being tilted out of line.

• In Morrey's modification, Type 2 fractures involve > 30% of the articular surface and are displaced more than 2-3 mm.


Morrey's Modified Classification


radial head fracture without associated soft tissue injury or fractures


radial head fracture with a ligamentous injury and/or an associated fracture




• Simple fractures are graded using Mason's classification.

• Ligamentous injuries may involve the medial collateral ligament, lateral collateral ligament, or the ligament at the distal radioulnar joint (DRUJ).

• The term "Type 4" fracture was used for a fracture of the radial head that involved dislocation of the elbow joint. This is now referred to as a complex fracture involving the medial and/lateral collateral ligament.

• Injury to the ligament at the DRUJ was described by Essex-Lopresti (J Bone Joint Surgery. 1951; 33B: 244).


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