Salter-Harris IV fractures of the lateral condyle are the most frequent intraarticular fractures of the distal humerus in children.
The pattern of this fracture is characterized by a single epiphyseal fracture with a posterolateral metaphyseal wedge (Salter-Harris IV). There is a variation in the size of the metaphyseal fragment, depending on the anatomical alignment of the growth plate posteriorly. The classification is independent of fragment size and displacement.
The epiphyseal fracture may pass medial to the capitellar ossific center, or occasionally through it.
Another variation is in the initial stability of the fracture. Because of the thick epiphyseal cartilage around the capitellar ossification center, especially in younger children, the fracture at the level of the joint surface can be incomplete ("hanging fracture"). Hanging fractures can best be demonstrated by ultrasonography, or arthrography.
In these fractures there can be an associated injury of the medial collateral ligament. This can be evidenced by clinical tenderness over the damaged ligament. A medial injury is a strong indicator of elbow instability.
Other associated injuries include elbow dislocation, fractures of the radial head, or the medial epicondyle.