title: Proximal femoral osteotomy: a trigonometric analysis of effect on leg length.
abstract: A trigonometric analysis of the effect of a proximal femoral osteotomy, either dome or cuneiform, on leg length was done to aid the preoperative planning for this surgery. Change in leg length may be determined for a dome osteotomy by multiplying the length of the head-neck segment by the difference between the cosines of the preoperative and postoperative neck-shaft angles as measured from the vertical. A series of determinations are tabulated for a variety of head-neck lengths and angulation changes. When a cuneiform osteotomy is being done, the effect of the wedge can be determined and should be considered. Also to be considered are a tendency for spontaneous correction and growth stimulation from the osteotomy.
mesh_terms: D000293:Adolescent; D001846:Bone Development; D002648:Child; D002675:Child, Preschool; D005269:Femur / Q000601:surgery*; D006621:Hip Joint / Q000601:surgery*; D006801:Humans; D007223:Infant; D008433:Mathematics; D010027:Osteotomy / Q000379:methods*