RADIOLOGICAL DETERMINATION OF THE PRIMITI VE HIP CENTER IN HIP-DYSPLASIA

We studied 98 normal hips in 54 patients in order to assess precise se ttlement of the theorical hip center using the U landmark as reference i.e. determine A distance (vertical settlement) and C distance (horiz ontal settlement)) A being the vertical distance between U landmark an d the femoral head center, C the horizontal distance between U landmar k and the femoral head center. We found two indexes (A/E = 0,2 and C/D = 0,3 ) which allowed us to fix that center in vertical (A/E) and in horizontal (C/D) direction even in case of bilateral hip dysplasia, an d which can .be used either in pre-operative planning or in post-opera tive evaluation. D being the horizontal distance between the U landmar ks, and E the vertical one between the U landmark and the sacroiliac j oint.