Hip dysplasia refers to the improper development or anomaly of the hip joint socket. A malposition may develop in addition, known as hip luxation or hip joint luxation in the medical jargon. With a luxated hip, the femoral head is partially or entirely shifted relative to the hip joint socket, which means the head no longer engages properly in the socket.
With congenital hip dysplasia, the hip joint is not yet fully formed at birth. Girls are affected about six times more often than boys.
There are various possible causes of hip dysplasia – both internal and external factors can be involved.
An important external factor causing hip dysplasia in infants is a lack of space in the womb. If the femoral head shifts in the socket because of the child's restricted mobility and presses against the edge of the socket for a longer period of time, so that the socket becomes deformed, this can cause hip dysplasia with hip luxation. A lack of space can develop for the following reasons, among others:
- First-time pregnancy
- Breech position
- Low volume of amniotic fluid
- High blood pressure of the mother during the pregnancy
The typical symptoms of hip dysplasia and hip luxation, which may be minor or pronounced, are as follows:
- Instability of the hip joint
- Dislocation and re-setting of the femoral head
- Limited abduction of the affected hip joint
- Asymmetric folds on the back of the thighs
- Apparent shortening of the affected leg
Hip dysplasia and luxation usually occurs on one side (approx. 60%) but the symptoms may also occur on both sides. The first indication of hip dysplasia in newborns is an unstable hip joint, but this self-corrects in 80% of all cases. Hip luxation may result if pressure is applied to the femoral head from the outside (e.g when changing diapers with the hip joints extended).
If improper development is suspected following a physical examination of the infant, an ultrasound scan follows. This allows the doctor to evaluate whether the suspicion of hip dysplasia or hip luxation can be confirmed.
X-rays are only taken if treatment is necessary. In order to excluded the possibility of joint degradation (femoral head necropsy), final X-rays are taken after treatment.
Therapy depends on how severe the symptoms are, and on the age of the child at the time of the diagnosis. However, the following generally applies: The younger the affected individual, the more successful the treatment of hip dysplasia and hip luxation.
Often no therapy at all is required in early stages, since hip dysplasia frequently self-corrects within the first two months. You can promote the spontaneous healing of hip dysplasia by diapering your baby so that the hip is flexed, carrying it in a sling and consistently avoiding premature extension of the hip.
If hip dysplasia remains beyond the second to fourth week of life however, spreader pants are suitable for therapy. Your doctor decides whether muscle relaxation exercises and physiotherapy are indicated in addition. In case of hip dysplasia with hip luxation, the femoral head has to be repositioned in the socket. This can be achieved with the help of orthoses. Subsequently it is necessary to ensure that the femoral head does not dislocate from the socket again. This is also accomplished with the help of orthoses.