Pathogeny and natural history of congenital dislocation of the hip

Abstract

Based on a review of the literature, the authors have made a critical study of several etiological factors. Endogenous factors such as acetabular dysplasia, increased anteversion of the femoral neck, and capsular laxity support the genetic theory but are neither constant nor necessary and are only facilitating factors. The major factor seems to be a mechanical one linked to the position in the uterus: hyperflexion with adduction and external rotation constituting the dislocating foetal posture combined with abnormal pressure on the greater trochanter and leading to expulsion of the head upward and backward. This theory can explain the natural history of C D H which is first, at birth a hip instability followed by two possible evolutions: either persistent luxation becoming irreducible or spontaneous stabilisation leading sometimes to complete healing or to residual abnormalities (subluxation or dysplasia). This concept suggests practical conclusions: the importance of an early diagnosis, the selection of the signs of the hip at risk, the pattern of prevention, the role for non-clinical investigations, the principles of the treatment based on postures, the indications for the different types of treatment.

Prediction of mechanical behavior of cartilaginous infant hips in pavlik harness: A subject‐specific simulation study on normal and dysplastic hips

“…In any real joint, the degree of translation and the shift of CCP distribution would fall between these cases. Inferior shift of CCP may be desirable during PH treatment, because unloading the acetabular roof may encourage acetabular remodeling …”

“…) also indicated loss of contact between the femoral head and anterior acetabulum. The predicted dislocation of the dysplastic hips at relatively small abduction angle (40°) is in agreement with clinical observations/suggestions that dysplastic hips, under PH treatment, are prone to (re)dislocation if they do not freely abduct into the safe zone due to adductor contracture …”

“…In other words, different conditions of muscle stiffness/contracture determined the abduction angle at which the leg would eventually reach force equilibrium for a particular hip model. The assumption of 90° flexion for legs in a PH complied with the clinical target angle range (90° to 100°) of flexion for the treatment . Abduction angles were selected based on clinical experience: an angle of 40° is within the lower bounds of the safe zone less than which a dysplastic hip would redislocate, 60° is within the safe zone, and 80° is associated with high risk of AVN.…”

Developmental hip dysplasia in a 104-year-old patient

“…The abnormal contact may lead to a dysplastic acetabulum and sometimes to formation of a neoacetabulum when the joint is not reduced. Treatment today consists of reduction by means of splinting or sometimes surgery at a young age 1 2. DDH is an important risk factor for developing premature osteoarthritis of the hip, often requiring total hip arthroplasty 3.…”

Vojta method in the treatment of developmental hip dysplasia – a case report

“…Mostly, attention has been given to fetal positioning in the prenatal period, the effect of hormones on laxity of the articular capsule, and the genetic factor. However, an extensive review of the available literature by Seringe et al points to the positioning of the joint during fetal development as the most significant factor 2–5…”