Medial Condyle Fracture

Abstract

The medial condyle fracture is an uncommon injury in the pediatric population, accounting for 1–2% of all distal humeral fractures. A corollary to this fracture is the lateral condyle fracture, by comparison accounting for 17% of all distal humeral fractures. The mechanism for this injury is valgus load applied to an extended elbow, although other mechanisms have also been proposed. A thorough understanding of distal humeral anatomy and ossification is essential for proper diagnosis and treatment of this fracture. From proximal to distal, the medial condyle fracture travels from the medial condylar metaphysis typically through the common physeal line of the trochlea and capitellum as in Milch type I injuries Alternatively, the fracture line can pass through the capitulotrochlear groove as in Milch type II injuries. The medial condyle fracture is comprised of the medial epicondyle and the trochlea, which ossify at 5/7.5 years and 9/10.7 years, respectively, for girls/boys. The disparate ossification of these epiphyses may lead to misdiagnosis in younger patients with apparent isolated medial epicondylar fractures. In such patients, the medial condyle fracture is comprised of the ossifying medial epicondyle and the cartilaginous trochlea. Medial epicondyle fractures are Salter Harris IV physeal fractures and involve the elbow joint. Minimally displaced fractures may be treated with long arm cast immobilization and close surveillance. Open reduction and internal fixation with smooth Kirschner wires or screw fixation is indicated for greater displacement to avoid nonunion and long-term morbidity.