Congenital hip dislocation

Incidence: it occurs by 2 or 3 children per 1000 live births. it is common in female than male by ratio 5:1.

Etiology: there is many factors that may lead to this congenital anomaly:

1) Ligamentous laxity around hip joint result from familial mesenchymal tissue disorders and cartilagenous limbus which form the rim of the acetabulum  that is inverted inside the acetabulum.

2) The head of the femur is flattened.

3) Breech presentation during delivery.

4)Shallowing of the acetabulum.

5)Sever hypotonia with generalized joint laxity.

The dislocated femoral head is directed superior and posterior to the acetabulum leading to :

1)Elongation of the ligamentum teres .

2)Contraction of psoas, adductor,and hamstring muscles.

3) Separation of the gluetus medius from the ilium.

4) Stretching of the joint capsule.

Clinical presentation:

1) Skin fold on the gluteal and adductor region .

2) Limitation of passive hip abduction.

3) Old child who begins to ambulate show positive trendelenburg sign.

4) Child with bilateral CHD has waddling gait.

Diagnosis:

1) Plain X- ray:we can see shallowing of the acetabulum and shape of the femoral head.

2) CT ultrasonic : is used for intra utrine investigation.

Special tests for hip instability in infants.

1) The ortolani test: chid lies supine  with his hip and knee are flexed.

      Grasp: the therapist hold legs at the femoral condyles with his index and middle finger on the lateral aspect of the thigh on the greater trochanter.

both legs are rotated through full arcs of external rotation and abduction.

the normal hip can be brought into 90 degree of abduction but the dislocated hip blocks usually at 30 to 40 degee of abduction and external rotation.

2)Piston test: child lies supine with hip flexed 90 degree and adducted and the knee is flexed . the therapist grasp thigh  with the opposite hand and the infant pelvis is supported with the other hand then move thigh up and down through its axis.

Normally , the hip is felt stable without telescoping of the limb.

If there is dislocation , the axial compression cuases the leg to be short so that telescoping is obvious.

3)Barlow's test: child is supine with his hips and knees are flexed.

the therapist grasp the normal side of the pelvis  with the opposite hand to this side and the examined hip is held between tip of middle and thumb .

the hip is adducted  if it is dislocated it can be pushed out of the back of the joint and reduced by pressure on the greater trochanters.

treatment

1) Reduction of the joint with minimal soft tissue injury .the child is put in quadriped position and use splint that keep hip in abduction . it may be one of the following:

a- Traction :weight traction can be used to reduce dislocation . the hip is moved gradually in wide abduction  in either extension or flexion.

b- Splinting:

1-Frejka pillow.                                                              2-Von Rosen splint.

3-Denis brown hip splint.                                            4-Pavlik harness.

5-Plaster hip spica.

2)  physiotherapy:

1- Mobilization in warm water is very useful.

2- weight bearing activity as standing and walking.

3- Walking using crutch is better than using walker as it allow active hip and knee flexion.

4- Using tread mill for strengthening and endurance.

Surgical management:

1-Closed or open reduction may be done with or without musclotenotomies.the hips are placed in abduction and immobilized with plaster which is maintained for 9 months depending on child age and type of surgery .

2- Pelvic osteotomy : is used for children between 18 months and 10 years of age . they are immobilized in plaster hip spica for up to 8 weeks.

3- Steel triple osteotomy : is done for children with age of 12 years  and older child . they require 120 weeks for immobilization in hip spica

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