There are specific forms of nonunion secondary to per-inter-subtrochanteric fractures that make surgical planning a critical phase. In cases such as these, it may be useful to transform the center of the nonunion into an osteotomy plane. Because of the anatomotopographical features, course and progression of the lesion, cases such as these constitute a pathology that is difficult to define in terms of a therapeutic protocol. The authors report the surgical technique used in 4 cases of nonunion of the proximal metaphysis of the femur.