Abstract
1 . A series of 343 tibial shaft fractures proceeding to sound union in adults, and 192 fractures in children, was studied. Groups of fractures differing from each other only in the one particular variable under consideration were compared.
2. The severity of the injury (as assessed by the degree of displacement, of comminution and of compound wounding) was found to be an important determinant of speed of fracture union and of incidence of delayed and non-union. A simple classification of severity of injury is described.
3. Distraction delayed healing. Traction which avoided distraction had no effect on the rate of union of fractures of moderate severity compared with cases of similar severity of injury treated by immobilisation only. Major fractures subjected to traction did take longer to unite on the average, but there was no increase in the incidence of delayed or non-union.
