Prediction of overgrowth in femoral shaft fractures in children.

A prospective study of femoral shaft fractures in children under the age of 14 years has been carried out in 71 patients who were reviewed both clinically and radiographically at yearly intervals. The processing of data has been carried out by univariate and multivariate analysis. Femoral overgrowth (F.O.) averaged 8.63 mm (range 1-21 mm), and was found to be influenced by age (greater overgrowth in children between 3 and 9 years), the initial displacement of the fracture (greater overgrowth in severely displaced fractures), and overriding of the fragments at the time of healing (the greater the overriding the lesser the overgrowth). Consideration of these factors allowed overgrowth to be predicted from the time of fracture. Overgrowth occurred in all children over 2 years of age, and took place mainly during the first year after the fracture. It continued, although to a lesser extent, during the second year, and for as long as the fifth year in 27%. After this time the growth rate of both femurs was equal in all the children. Ipsilateral tibial overgrowth was present in only 60% of the children and averaged 1.05 mm (1-5 mm).