Avulsion fractures of the proximal tibial epiphysis.

Fractures of the tibia through the proximal epiphysis are rare. This injury usually results from severe direct or indirect force about the knee, and has not been described as resulting from a patellar tendon avulsion injury. Four patients presented with five avulsion fractures of the proximal tibial epiphysis. All were older adolescent males who had been engaged in jumping sports when the injury occurred; one had bilateral injury. All the patients were treated by closed reduction and plaster cast immobilization for 4-8 weeks, with satisfactory results. On the basis of our cases and five cases previously reported, the authors would agree with Ryu and Debenham's suggestion that the Watson-Jones classification, which divides avulsion fractures of the tibial tubercle into three types, should be expanded to include this fourth type - avulsion fracture of the proximal tibial epiphysis.