In frontal reaxes of genu varum arthrosics by tibial osteotomy,the internal opening osteotomy has the advantage of avoiding any vascular-nervous complication (paresis of the pernoeal nerve, chamber syndrome(?), encountered in external closing osteotomies, and in rare arthrites noted in vault osteotomies of external setting.
The substitution of the iliac tricortical grafts, which maintained the opening of the osteotomy, for a cement wedge (created at the beginning of the intervention) has permitted the elimination of complications due to the hold of iliac grafts (hæmatoma, suppuration, pains).
The stabilization of the setting with an antero-internal support plate, based upon the shape of the tibia after the opening osteotomy, avoids all correction loss (the epiphysis above the osteotomy and the diaphysis below are each set with 3 cortical screws of 5 mm diameter).
The bone regrowth of the osteotomy occurs from the outside to the inside without any local bone contribution. Progressive support is possible starting on the 45th day; complete support is authorized between the 70th and the 75th operative day.
This technique seems to be very accurate since 75 % of the osteotomies solidify with the desired valgus (between 3° and 6° of valgus on the mecanic axes), and the greatest part
of the errors of correction is only 1° from the ideal valgisation area. Finally, the plate is almost always tolerable and its ablation, in case of pain, is unusual.