Hip stress reduction after Chiari osteotomy

Abstract

A mathematical model was developed to study the effect of the Chiari osteotomy on the distribution of contact hip stress over the weight-bearing area. It was shown that Chiari osteotomy can increase the weight-bearing area directly (on the lateral side), owing to the additional area formed by the ala ossis ilii segment, and indirectly (on the medial side), owing to the shift of the stress pole in the medial direction. As a consequence, the contact hip stress is reduced after Chiari osteotomy. The indirect effect is important and often larger than the direct one. Using the proposed mathematical model and standard anteroposterior roentgenographs from archives, the average peak stress on the weight-bearing area, normalised with respect to the body weight (pmax/ W(B)), was determined before and after Chiari osteotomy (8,310m(-2) and 4,480 m(-2), respectively) on a population of 29 dysplastic hips. The difference was statistically significant (p < 0.005). Based on the results presented, it can be concluded that the hip joint contact stress in dysplastic hips considerably decreases after Chiari osteotomy, indicating a favourable biomechanical effect of this operation.

Impact of triple pelvic osteotomy on contact stress pressure distribution in the hip joint

“…This is very important because a favourable force distribution decreases the chance for the development of hip joint degenerative changes. The increase of the lateral coverage of the femoral head actually causes an augmentation of the weight bearing area medially due to redistribution of contact hip stress [25]. This indirect effect is larger than the direct effect of increasing the lateral femoral roof.…”

“…The HIPSTRESS method was used in the analysis of healthy and dysplastic hip joints [17,18], various disorders of the hip [14,[19][20][21][22], and after different surgical procedures, e.g. corrective femoral osteotomies, and Salter, Chiari and Ganz pelvic osteotomy [12,18,19,[23][24][25][26]. It is now applied for the first time in the analysis and quantification of Tonnis triple pelvic osteotomy effects.…”

Acetabular Loading in Rehabilitation

“…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.…”

“…If the alternative spherical coordinate system is used the calculation of the integrals in vector Eq. (11) becomes much more simple and transparent (Herman et al, 2002). The alternative spherical coordiwww.intechopen.com…”

Cumulative Hip Contact Stress Predicts Osteoarthritis in DDH

“…Peak contact stress in the hip has been compared between different groups of patients with developmental dysplasia of the hip to evaluate outcomes of surgical procedures [12,37]. These and other experimental studies [29,36] and clinical reports [13,25] confirm patients with hip dysplasia have higher contact stress than healthy subjects.…”