Roentgen stereophotogrammetric analysis of growth pattern after supination-adduction ankle injuries in children.

In a prospective study of supination-adduction (SA) ankle fractures in children, the post-traumatic growth pattern was registered with a roentgen stereophotogrammetric technique allowing exact determination of the growth rate within 3 months after fracture. It was possible to predict future growth pattern within 6 months. The SA injuries (10 cases) were divided into two stages according to Gerner-Smidt. One Stage I injury (physeal separation through the distal fibula) showed a growth stimulation. Nine Stage II injuries (including a fracture through the medial malleolus) showed four types of growth pattern besides symmetrical growth. The Salter-Harris classification alone showed no obvious correlation to the post-traumatic growth pattern, whereas factors such as age at injury, stage of injury, displacement, and treatment in combination with the Salter-Harris classification contributed to a better prediction of risk of deformity. It was found that displaced Stage II injuries in the younger child had the highest risk of developing a clinically significant varus deformity. Early determination of the post-traumatic growth pattern is of crucial importance in SA injuries with a high risk of growth deformities. Operative treatment in order to restore normal growth can be performed before a severe deformity has developed.