In many cases it is necessary to employ the lever motions across the posterior border of the acetabulum. The leg is flexed to right angles and then extended. The thigh is gradually abducted more and more while the thumb of the other hand or the underlying fist presses against the trochanter (reduction across the posterior border of the acetabulum) (Fig. 4Se).
In difficult cases Lorenz makes use of a padded wedge of wood which he places beneath the dislocated hip for the purpose of facilitat ing the reposition. Manual reduction is less irritating. If this does not succeed, an attempt should be made at reduction across the lower border of the acetabulum with motions similar to those made with a pump handle (lion). The abducted leg bent at right angles is pushed in a horizontal plane to and from the body. Pressure on the knee in marked flexion and adduction forces the head across the lower border of the acet a bul um.
When the head slips into the acetahulum a characteristic and typical snap is heard. The head can then be plainly felt beneath the femoral artery. This snap is not very distinct in the flat cartilaginous aectab ulum of young children. The head can be felt at this point projecting in hemispherical form on increasing the abduction and hyperextension. It does not remain in this position long, but with a perceptible motion it slips away from the acetabulum. The stability of the head varies and is mainly dependent on the depth of the aeetabulum and the interposi tion of tissue (capsule, ligamentum teres).
Retention aims to fix the head in the most favorable position.
This is best accomplished by applying a tight-fitting plaster band age which encircles the pelvis and femur. Surgeons differ in their methods as to the primary position of the head and the extent of the bandage.
The author applies the bandage in a position which insures the great est stability to the head Only a small amount of padding is used and the bandage is extended up to the border of the ribs and downward to below the knee (Fig. 4Sd). Flexion from 70° to 90° is made with a somewhat greater degree of abduction. In order to increase the stability it is sometimes necessary to antevert the femoral neck and rotate it inwards. Children bandaged in this manner can walk on the ball of the foot with the heel raised. It is better not to allow the child to walk on
the feet but rather to build in a crutch in the femoral part of the band age (Fig. 4Se) with b ic h the child soon learns to walk (Codivilla). This enables the child to walk with an even more pronounced inward rotation.
The first cast should remain in position for three to six months. If there is any doubt as to the retention the cast should be removed and the position examined by the Rontgen rays. A radiograph can be made without removing the entire cast bandage by cutting out windows in the bandage (Klapp). If the position is satisfactory no change should be made until the period of fixation (three to six months) has elapsed. The plaster bandage is then gradually and carefully readjusted to the normal position. Under the guidance of the X-ray this can be accom plished without the head slipping out of position. A second cast is required in nearly every case, depending on the amount of stability and the condition of the head and aeetabulum. Each case must be con sidered individually, for mechanical routine in every case is impossible.
The durat,ion and position of the second cast depend entirely on the case. The length of treatment :s generally from five to twelve and even longer. When a satisfactory stability has been attained the bandage is removed and the child encouraged to make active motion. may be carefully used when the unrestrained motions have returned the leg to a natural position. Force should not be applied. When the child begins to walk the sound leg is raised by building up the sole of the shoe. This insures the maintenance of abduction in the affected leg.
Bilateral dislocations of the hip are generally reduced at one sitting and fixed by means of a eorresponding east. The treatment with the plaster-of-Paris bandages takes longer than in unilateral dislocations (Fig. 49, Plate 6).
The consists of active gymnastic exercises, especially in abducting the leg and strengthening the muscles which support the pelvis. It is advisable to have the children wear a support around the pelvis at night., which will hold the head in the joint. Reiner and Lange advocate wearing pelvic rings made of celluloid and steel wire.