Longitudinal growth of the femur and tibia after diaphyseal lengthening.

Growth of the femur and tibia after lengthening of their diaphyses, which had been performed several years before skeletal maturity, was assessed in eighteen patients by serial orthoroentgenograms. The rate of growth of the lengthened femora, which had been congenitally short, increased after each of seven lengthening procedures, from an average preoperative rate of 82 per cent of the normal side to 90 per cent of the normal side. The amount of surgical lengthening was similar for the femora and the tibiae, averaging 18 per cent of the preoperative length of the bone in the femora and 20 per cent of the preoperative length of the bone in the tibiae. However, the rate of growth of the lengthened tibiae decreased after each of eleven lengthening procedures (six performed for a congenital short tibia; three, for patients who had Ollier's disease; one, for a patient who had poliomyelitis; and one, for a patient who had hemangiomas), from an average preoperative rate of 88 per cent of normal to an average of 64 per cent of normal.