Manual of Surgery Volume Second: Extremities—Head—Neck. Sixth Edition.

by Alexis Thomson; Alexander Miles

To keep the head in the socket, the limb must be maintained in the position of right-angled abduction and external rotation (90°) by a plaster case, which includes the lower part of the trunk and both limbs down to the knee. Under the plaster, stockinette drawers are worn, and the bony prominences are padded with cotton wool. The plaster should overlap the costal margin. The first case is worn for two months or more, and is then renewed at shorter intervals, the degree of abduction being diminished at each renewal until the limbs are nearly parallel. The child is only kept in bed for a week or two, and is then allowed up, being provided with a boot and high sole on the affected side, but should not use crutches. At the end of six months, by which time the capsule has become tightened up round the head of the femur, the plaster is given up and massage and exercises are employed.

In bilateral cases both dislocations are reduced at one sitting if possible, and a plaster case applied with both thighs abducted and flexed to a right angle, the so-called “frog position.”

In the event of failure to reduce a dislocation at the first attempt, the limb should be fixed in plaster in the abducted attitude for ten days or a fortnight, and then another attempt made. The greatest number of successes in bilateral cases is met with under five years of age, and in unilateral cases under seven. Reduction may sometimes be accomplished, however, in older children.

If it is found impossible to restore the head of the femur to the acetabulum, an attempt should be made by similar manipulations to wedge it under the long head of the rectus femoris, or, failing this, below the anterior iliac spine under the sartorius and tensor fasciæ femoris. By thus converting a posterior into an anterior dislocation, the tilting of the pelvis and the lordosis are greatly diminished. This procedure, named by Lorenz anterior transposition of the head of the femur, is specially applicable to cases in which relapse has taken place after reduction, and to those above the age when reduction should be attempted.

Reduction by open operation may be had recourse to in cases in which, after several attempts, reduction has failed, or in which re-dislocation has occurred; it is, however, a serious operation. Attempts have also been made by means of pegs and other contrivances to fix the head of the bone and prevent it sliding upwards on the ilium. When reduction is impossible by any means, a stiff leather jacket with prolongations around the thighs may diminish the deformity and improve the walking.

Snapping Hip (Hanche à ressort).—This is a rare affection, met with in children and young adults, and characterised by the occurrence of a sudden, snapping sound, sometimes attended with pain in the region of the great trochanter. This usually occurs when the limb is slightly flexed or adducted, and rotated either inwards or outwards. On palpation a cord-like structure may be felt, which slips forwards and backwards over the trochanter when the position of the limb is altered.

The condition was formerly described as a voluntary dislocation of the hip; it is now believed to be due to a cord-like band of tissue slipping backwards and forwards over the trochanter. The band is usually derived from the fascia lata, sometimes reinforced by the anterior fibres of the gluteus maximus, sometimes by the tensor fasciæ femoris. The condition seldom gives rise to any appreciable disability and surgical treatment is rarely called for. In a number of cases the muscle has been fixed by sutures with satisfactory results. In a recent case, an extensive open dissection proved negative, but the stitching of the gluteus to the trochanter was followed by the disappearance of the snapping.

Paralytic Deformities of the Hip.—In anterior poliomyelitis the paralysis of muscles may be so widespread that the limb is unable to support the weight of the body, or certain groups of muscles only are paralysed and the child may be able to walk with the help of apparatus. Even if the ilio-psoas is paralysed, flexion is still possible by the anterior fibres of the gluteus medius, the anterior adductors, and when the leg is rotated out by the tensor fasciæ and sartorius, the dislocation differs from the traumatic variety in that the head, although it leaves the socket, remains within the capsule. Dislocation tends to occur from the disturbance of muscular balance, anterior dislocation being commoner than posterior in about the proportion of two to one; the nature of the dislocation is best demonstrated by means of the X-rays. Reduction is rarely possible without an open operation. Tendon and nerve-transplantation are scarcely possible, and arthrodesis is rarely to be recommended; contracture deformities, however, are often benefited by tenotomy in young children, and in older children by osteotomy through the trochanter, and putting the limb up in the abducted position.

In spastic paralysis of cerebral origin, the tendency is towards contracture, usually in the attitude of flexion, with adduction and inversion. This may result in dislocation backwards on to the dorsum ilii, and may occur in patients confined to bed ([Fig. 131]).