adduction deformity of the hip, postural scoliosis, and a valgus deformity of the knee may develop.
– the following are blocks to reduction of CDH: inverted labrum, pulvinar, capsule (hour glass constriction), ligamentum teres, psoas tendon (causes the hourglass constriction); acetabular version does not influence reduction.
– in a 4 year old with CDH, doing a closed reduction will be very hazardous for creating AVN.
– extreme abduction will cause AVN in CDH. Extreme hyperflexion may force the heads inferiorly within the acetabulum.
– a truly congenital dislocation of the hip (present at birth) is uncommon. It is more common on the left.
– indications for Chiari include coxa magna with subluxation laterally.
– in a child with CP, innominate osteotomy is inappropriate because acetabular deficiency is not the problem, at least not initially – this is a paralytic problem. Later on, there may be acetabular deficiency more POSTERIORLY – treat with Dega osteotomy.
– the following portends a worse prognosis in Perthes: whole head involvement, females (tend to get more head involvement), loss of containment, and the presence of metaphyseal cysts.
– the Caterrall “Head at Risk” signs for Perthes include: Gage’s sign, metaphyseal cysts, horizontal physis, lateral epiphyseal calcification, lateral subluxation. In the final analysis, age of onset beyond 8, and involvement of the lateral pillar may be the worst.
– for the older DDH kid with trochanteric overgrowth because of AVN, surgical alternatives to deal with the limp and trendelenberg include either a growth arrest of the GT if young, and if older, a distal transfer of the GT.
– the classic age for Perthes is 4-9, although it can appear in kids as young as 2, and as old as 12.
– Coxa breva secondary to Perthes is a result of AVN – the neck is short, and often in varus with trochanteric overgrowth. Do no treat this with a varus osteotomy. Abductor strengthening, and distal/lateral transfer of the GT may be helpful.
– the worst of the femoral neck fractures is the transepiphyseal (Delbert I). With dislocation of the head, the AVN rate approaches 100%. Rates for the remaining probably depend mostly on displacement, although the interesting thing is that the basicervical fractures (III) have an AVN rate of nearly 25%, which is very different than in the adults.