[Van Nes rotation osteoplasty in congenital dysplasias and aplasias of the proximal femur in young children. A study of 6 cases].

Six rotation-plasties, as described by Van Nes, have been carried out in children between 5 and 11 years of age, 5 of whom had congenital defects of the proximal femur, and the other femoral hypoplasia. The operation involved arthrodesis of the knee, accurate shortening of the leg so that the ankle would be at the same level as the opposite knee at the end of growth, and clockwise derotation of the leg through 180 degrees. The only complications encountered were 3 transient palsies of the peroneal nerve. Rerotation was only required if the operation was performed in early childhood, or if it had been carried out counterclockwise. The ideal age for operation seems to be between 8 and 10 years of age. The results are satisfactory. Function and gait are improved. The prosthesis may need to be long because of the pelvi-femoral instability associated with the basic deformity. The operation is indicated in some children with congenital abnormalities of the femur who would otherwise require a rigid brace or an amputation to accommodate a prosthesis.