殿筋群を剥離しない新しい寛骨臼回転骨切り術 骨盤内側からのｐｅｒｉａｃｅｔａｂｕｌａｒ ｏｓｔｅｏｔｏｍｙ

Abstract

The Bernese periacetabular osteotomy described by Ganz et al restores the position and acetabular coverage of the dysplastic hip to nearly normal, but it has several disadvantages due to the asphericity of the osteotomy surfaces. Because this osteotomy is a series of straight cuts, incongruity at the site of the osteotomy and anterior displacement of the hip joint may occur in patients who need an extensive acetabular reorientation. We designed a curved periacetabluar osteotomy to improve these drawbacks.The direct anterior approach described by Murphy et al is used with the patient supine. The triple osteotomy is done with a specially curved osteotome, designed to approximately correspond to the circumferential curvature of the acetabulum. Except for the use of the osteotome, an incomplete cut of the ischium and a complete cut of the pubis are performed in the similr manner as those of the Bernese periacetabular osteotomy. The first step in osteotomy of the ilium is to score the inner table of the pelvis with a power drill. A C-shaped osteotomy line is started proximal to the anteroinferior iliac spine and ended in the distal part of the quadriilateral surface. The actual osteotomy along the scored line is done with the osteotome being directed proximally in the supraacetabular portion, posteriorly in the proximal part of the quadrilateral surface, and distally in the distal part of the quadrilateral surface. Then, the acetabular fragment can be redirected and is fixed with two or three screws. The posterior column of the acetabulum is kept intact. The results of the first 24 hips in 24 patients were prospectively studied with a minimum of 6-month follow-up. All hips had residual hip dysplasias. At operation, the osteotomized acetabular fragment was rotated without difficulty and was medialized as necessary. The averge lateral center-edge angle was 6 degrees preoperatively, compared with 29 degrees postoperatively. The average anterior center-edge angle was 8 degrees preoperatively, compared with 26 degrees postoperatively. Bone union and relief of pain were obtained in all hips.