Hip dysplasia

What is meant by hip dysplasia?

Hip dysplasia or developmental dysplasia of the hip (DDH) is a developmental disorder of the hip joint. The development of the human hip joint takes place in the womb. In the ideal case, an optimum shape and string connection forms which will enable a lifelong problem-free function. Unfortunately, both genetic and external factors can adversely affect the development, so that premature degeneration of the joint cartilage threatens.

Even if most hip dysplasias can be identified in new-born screening by ultrasound and treated appropriately, a hip dysplasia still remains in some patients.

Where there is evidence of hip dysplasia, an operation is therefore usually recommended to counter premature wearing of the hip and support normal development of the hip joint.

Two healthy hip joints of a 10-year-old girl are shown here. The so-called CE-angle or Centre Edge angle increases with advancing age. Determination of this, along with other angles, serves as a diagnostic tool in the decision of what treatment procedure or operations could be necessary. The CE-angle for children up to 13 years old should be greater than 20° and for adults greater than 25°. Patients with hip dysplasia have smaller values.

The hips of a 13-year-old boy with hip dysplasia in both hip joints are shown. The so-called acetabular coverage of the femoral head was improved on the left side significantly by a so called triple pelvic osteotomy. The CE angle improved accordingly.

Symptoms of hip dysplasia

Patients with hip dysplasia are often asymptomatic. However, groin and thigh pains often arise with gentle to medium-intensity activity. Where there are injuries to the labrum (frame of the joint socket) obstruction and “clicking”-phenomena can also occur.

Hip dysplasia operations

Because of the short socket, there can be an overload of the joint at the edge of the socket. Shearing forces arise because of the pull of the muscles and the inclination of the socket, which exacerbate the situation and cause cartilage damage.

The aim of surgical treatment is to increase the contact surface of the hip joint, relax the capsule and the muscles and improve the cantilever effect to prevent joint instability and arthritis.

Particularly in infants and young children, the re-establishment of normal hip geometry can be the pre-requisite for promoting healthy reconstruction, ameliorating symptoms and improving the quality of life. In very severe cases, the aim of the operation can also be to delay the time at which an artificial hip replacement will be needed.

Whilst there are no operative procedures available for infants, operations on the bone represent the standard procedure in children older than 2 years. There are numerous surgical procedures which depend on the severity of the dysplasia, appearance of the hip joint, accompanying disorders and experience of the surgeon.

Pelvic osteotomies

The socket (acetabulum) is reconstructed in pelvic osteotomy. They correct the insufficient acetabular coverage of the femoral head. To strengthen the osteotomy, wires or screws are fitted to the bones in the operation to secure the new position.

In severe cases, it can be necessary to also carry out an osteotomy on the femur.

PICTURE ACETABULOPLASTY

The illustration shows a 4-year-old child with a hip dysplasia who has been treated with a so-called acetabuloplasty. In this, the roof of the socket is pulled downwards, and the cavity created is filled with bone. This type of pelvic osteotomy does not usually require wires or screws for fixing.

PICTURE SALTER AND FEMORAL OSTEOTOMY

The illustration shows a 6-year-old boy with a severe deformation of the left femoral head caused by an avascular necrosis of the femoral head (Legg-Calve Perthes Disease). To correct the acetabular coverage of the femoral head (containment), a Salter pelvic osteotomy and a repositioning osteotomy of the femur were carried out.

Post-operative immobilisation

After surgery, it is often necessary to immobilise the patient. Previously, this was primarily done with a Spica cast (pelvis-leg plaster cast) which led however, to a significant restriction in the quality of life and to hygiene and skin problems. Today, modern positioning systems are used which offer soft bedding with the same stability. Hygiene and early functional treatment can be much better managed by this as well.

The positioning system is individually made in advance by the orthopaedic technicians we work with so that immobilisation treatment can begin immediately post-operatively.

PICTURE POSITIONING SYSTEM

The pictures show the process of adjusting the positioning recesses to immediate post-operative application.