The classification is numerically based upon a worsening severity such that type I and II have an excellent prognosis, although complete or partial growth arrest may occur in displaced fractures.
The excellent prognosis is due to the fact that the germinal layer is usually left intact so that growth disturbance is uncommon.
Types III and IV have a worse prognosis, as growth arrest and angular deformity are common problems. Involvement of the germinal layer make growth disturbance and functional impairment more likely if not managed correctly.
Additionally special attention should be paid to types III and IV because of the intra-articular component.
Type V fractures have poor prognosis. This crushing type of injury was not originally described by Salter and Harris. It is rare and has a poor prognosis due to disruption of the blood supply to the epiphysis.
Unfortunately, this is usually diagnosed retrospectively when limb deformity becomes apparent.
Learning bite
Children have physes and any injury involving this region must be treated carefully in case of later growth disturbance. The physes are weak links in the growing skeleton and account for the difference between the location of fractures in children and adults.