ONE-STAGE STEPPED PROLONGATION OSTEOTOMY OF THE FEMUR

Intraindividual length differences up to 1.2 cm in femora, up to 1.0 c m in tibiae and up to 1.4 cm in whole leg length can be regarded as ph ysiological. Length differences in childhood are frequently compensate d for by functional adaptation in the chain of adjacent limbs. In adul ts, however, that adaptability is diminished and correction osteotomy after post-traumatic shortening may therefore be indicated more genero usly dependent on local and general criteria of operability. A conscie ntious analysis of bone geometry by clinical means, radiology and comp uted tomography is mandatory for the indication and planning of any co rrection osteotomy. Intraindividual leg length differences of more tha n 4 cm are preferentially treated by continuous callus distraction tec hniques. Shortening by less than 4 cm, however, is suitable for a one- stage stepwise prolongation osteotomy in the metaphysis of the femur, i.e. in the subtrochanteric or supracondylar region. These osteotomies are than stabilized by long condylar plates; the bony defects are fil led up by auto-or allogenous corticospongeous bone. Simple modificatio ns of the stepwise prolongation osteotomy permit additional correction s of torsional deviations up to 20 degrees or of axial deviations in t he frontal or sagittal plane up to 5 degrees. The results of 24 one-st age stepwise prolongation osteotomies of the subtrochanteric and supra condylar femur after congenital or post-traumatic shortening are prese nted as well as the reason and respective therapies for three importan t complications.