The purpose of this study was to determine the incidence, location and contributing factors of the bony spur formation following lateral condyle fracture of the humerus in children.

Sixty four lateral condyle fractures of the humerus followed up until bony union were retrospectively reviewed in the type of fracture, accuracy of the reduction, and the formation, size, location of the bony spur on serial radiographs. Treatment method was recorded.

In all children but one case showed bony spur formation in plain radiograph, be it large or small. The size of bony spur was not correlated with the extent of displacement nor treatment methods, but significantly related with the accuracy of reduction. In long term follow-up, the bony spurs decreased in size.

Accuracy of reduction determinates the size of bony spur following lateral condyle fracture of the humerus in children. In order to prevent or minimize the bony spur formation, accurate reduction is desirable. Even if bony spur formation was present in early healing stage, it can be expected to decrease in size.