Proximal femoral osteotomy: a trigonometric analysis of effect on leg length
Harper, M.C.; Canale, S.T.; Cobb, R.M.
Journal of Pediatric Orthopedics 3(4): 431-434
1983
ISSN/ISBN: 0271-6798 PMID: 6630485 Document Number: 216238
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.