A New method of performing a dihedral trochanteric osteotomy was designed to overcome osteotomy nounion and trochanteric bursitis secondary to wire breakage. The osteotomy was performed in two-steps with a side-cutting power saw and was started distal to the abductor tubercle. The first step of the osteotomy was done in an oblique direction similar to the usual fashion and stopped en route from the abductor tubercle to the femoral neck. Next, the blade of a side-cutting power saw was inserted between the capsule of the hip joint and the tendons of the gluteal muscles. The second step of the osteotomy was performed in a vertical direction from the tip of the greater trochanter until it reached the site of the first osteotomy. A v-shaped osteotomy of the greater trochanter was compleated with the apex of the osteotomy medical and the trochanteric fragment was retracted proximally. After operative procedures to the acetabulum were done, the trochanteric fragment was reduced into the original position and fixed with a single screw. The results of the first 24 hips in 23 patients were prospectively studied. At operation, reduction and fixation of the trochanter to its bed were easily performed because of the dihedral osteotomy. This method was found neither to prolong the operation time nor to increase blood loss. In all hips, osseous union of the greater trochanter was obtained and there was no trochanteric bursitis. The advantages of this type of osteotomy are obvious. Not only is rotation resisted but anatomical replacement of the trochanter is made easier, and the surface area of the osteotomy is increased.
