Classify epiphyseal injuries. Describe the treatment principles and complications of each type.

Epiphyseal injuries: foundational concepts

Epiphyseal injuries are fractures involving the growth plate (physis), with or without extension into the metaphysis, epiphysis or articular surface. They are important because injury to the physis may disturb endochondral ossification, producing premature physeal closure, angular deformity or limb-length discrepancy. The risk depends on the child’s age, the anatomical site, the amount of displacement, the energy of injury, the vascularity of the epiphysis and the adequacy of reduction.

The physis is weakest in tension and is commonly injured by shear or distraction. Histologically, the hypertrophic and provisional calcification zones are particularly vulnerable. The surrounding perichondrial ring, metaphyseal vessels and epiphyseal blood supply influence healing. A physeal fracture may be radiographically occult initially, especially in younger children; therefore, clinical tenderness directly over the physis is significant even when plain radiographs appear normal.

Salter–Harris classification

The standard classification is the Salter–Harris classification. It is based on the course of the fracture line in relation to the physis, metaphysis and epiphysis. It predicts the likelihood of growth disturbance and guides the need for anatomical reduction.