Weiss classification of lateral humeral condyle fractures

The Weiss classification is one of the classification systems used for lateral humeral condyle fractures and is based on the degree of displacement measured on an internal oblique view of the elbow:

• type 1: <2 mm displacement
• type 2: 2-4 mm displacement
• type 3: >4 mm displacement

The degree of displacement is used when determining the risk of future increased displacement and therefore determines which patients require operative management.