Deformity after internal fixation of fracture separation of the medial epicondyle of the humerus

We reviewed 24 displaced fractures through the physis of the medial epicondyle of the distal humerus. One was a Salter-Harris type-II fracture-separation of the whole distal humeral epiphysis; the others involved only the medial epicondylar centre of ossification. Two cases had presented as pseudarthroses. One fracture had been treated closed in a plaster slab and 21 had had open reduction and internal fixation with sutures, Kirschner wires or Palmer nails. At 2 to 13 years later we found five types of deformity of the epicondyle: pseudarthrosis, an ulnar sulcus, a double-contoured epicondyle, hypoplasia or hyperplasia. Pseudarthrosis had developed after either no treatment, closed reduction and plaster, or open reduction and suturing. Hypoplasia followed nailing, as did a trend to varus tilting of the joint surface. One very young patient, with fracture-separation of the whole distal epiphysis treated by nailing, developed marked cubitus varus.