Effect of the periacetabular osteotomy on the stress on the human hip joint articular surface

Abstract

Long-lasting over-elevated stress on the hip joint articular surface can damage the articular cartilage and is connected with arthrosis development. Periacetabular pelvic osteotomy is performed in order to prevent arthrosis development in different cases of residual hip dysplasia where the stress on the hip joint articular surface is increased because of inadequate femoral head coverage, i.e., too small hip joint weight bearing area. The aim of this work is to estimate a decrease of the stress on the hip joint articular surface after the periacetabular osteotomy. For this purpose, a three-dimensional mathematical model is constructed taking into account the spherical shape of the femoral head and of the acetabulum inner surface before and after the operation. On the basis of the presented results it is concluded that while performing the periactabular osteotomy the proximal part of the acetabulum should be rotated over the femoral head in lateral direction with the simultaneous medial displacement of the whole joint. In this way postoperative stress on the hip joint articular surface is reduced to the greatest extent.

The Bernese periacetabular osteotomy: clinical, radiographic and mechanical 7–15-year follow-up of 26 hips

“…Accordingly, the magnitude of the resultant hip force increased in all stratification groups, which is consistent with theoretical predictions of the relationship between the center of rotation and the resultant hip force (Figure). Our clinical results have thus confirmed theoretical predictions (Iglič et al 1993b) that the resultant hip force itself is not an adequate biomechanical parameter for preoperative planning, and that rotational osteotomy can effectively reduce the contact hip stress although the resultant hip force may be slightly increased.…”

Acetabular Augmentation by Residual Hip Dysplasia

“…Previous studies found that in dysplastic conditions where ϑCE is small or negative, hip joint contact stress is higher than in hips with a larger ϑCE; however, stress can also be higher due to a higher or a too vertical resultant hip joint force (Iglič et al,1993a;Ipavec et al,1999;Genda et al,2001). The direction and magnitude of the resultant hip joint force R depends, among other factors, on the femoral and pelvic geometry (Brand , 1997;Iglič et al,1993b).…”

Acetabular Loading in Rehabilitation

“…In order to solve Eq. (11), the ordinary spherical coordinate system was used in the previous papers (Iglič et al, 1993;Ipavec et al, 1999). Classical spherical coordinates lead to the complex expression for the boundaries of the weight-bearing area.…”

“…In the rotated coordinate system the pole of stress P as well as force R lie in the y ′ a = 0 plane. For a force in y ′ a = 0 plane, method for determination of the position of the stress pole which was developed for the one-leg standing with the force in the frontal plane and acetabulum symmetrical with respect to this plane (Herman et al, 2002;Iglič et al, 1993;2002) can be used. In order to solve Eq.…”