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

In a prospective study of ankle fractures in children, the growth rate was registered with a roentgen stereophotogrammetric method. The injuries were classified traumatologically according to Gerner-Smidt and anatomically according to Salter and Harris. Twenty-six ankle fractures were classified as supination--eversion injuries. Of these, eight had intraarticular injuries, 16 had extraarticular injuries of the distal tibia, and two had a zigzag fracture through the growth plate of the distal fibula. Information about growth was obtained within 3 months after fracture, and the growth pattern was found stationary about 6 months after fracture. Five types of growth pattern were observed: Normal growth (1 case), initial growth stimulation of varying length (8), initial and temporary growth retardation (1), initial and permanent growth retardation (4), and initial and permanent growth arrest (7). The other 5 had very low growth rates bilaterally. Roentgen stereophotogrammetry was found useful in extraarticular supination--eversion injuries in girls up to 12 years of age and in boys up to 13 years of age. Intraarticular supination--eversion injuries always appear when there is low remaining growth; because of growth disturbance, no follow-up is indicated. The traumatological classification was found of value in recognizing the different fracture types. Combined with an anatomical classification, high precision in predicting growth disturbance was obtained. However, factors such as trauma, displacement, skeletal maturity, and treatment must be considered. The roentgen stereophotogrammetric method permits early determination of the growth pattern with high accuracy. The growth disturbance can be registered months before this is evident from conventional radiographic examinations.