Effect on knee flexion of a modification to the surgical technique of pin placement during femoral lengthening.

Loss of knee movement is a common problem in femoral lengthening. Two groups of 10 children were compared: one group lengthened by the Ilizarov technique using a standard method and one group in whom the technique was modified to incorporate a different method for determining the pin placement. Loss of knee flexion was compared between the two groups. A significant difference in the total loss of flexion ( <0.002), and in the amount of knee flexion, at the end of lengthening ( <0.001) and at 6 months after frame removal ( <0.004) was observed. This simple modification to surgical technique appears to decrease the knee flexion lost in children undergoing femoral lengthening by the Ilizarov method.