CASE 2.—A child three years old. The mother states that several members of her family limp. The child started to walk when eighteen months old and has ever since waddled in a most peculiar fashion. Examination revealed a marked lumbar lo•dosis combined with a slight scoliosis to the left. While walking she swings the upper part of the body to and fro, more towards the left than to the right side.
Trendelenburg's symptom is present on both sides. Inspection from the front shows a prominent abdomen and backward displacement of the pubic region. It is found that on lying down there is a slight shortening of the left side. The legs are spread wide apart—only with difficulty. The trochanter is located above the Hoser-Nelaton line on both sides, the left one higher than the right. The head cannot be palpated beneath the femoral artery on either side. Diagnosis: Bilateral dislocation of the hip, the left head standing slightly higher than the right.
CAsrt 3.---A girl-baby three months old. The mother states that one leg is shorter than the other, that the baby does not move it as freely as the other and that it is somewhat thinner. The folds do not correspond on the two sides, especially the femoral fold at the origin of the sartorius muscle. An attempt to palpate the head reveals an empty acetabulum beneath the pulsating artery. The head is displaced up wards toward the anterior superior spine. Diagnosis: Unilateral con genital dislocation of the hip forwards and upwards (luxatio supra cot yloidca).
CAsn 4.—.1 girl twelve years of age limps heavily on the left side. She steps with the right foot more quickly than with the left and walks on her left toes. On examination she presents a marked seoliosis to the right which is compensated upon assuming the sitting position. The left gluteal fold is located higher up, because the child stands mostly nu the sound leg and tilts the pelvis upward on t he opposite side for the sake of stretching the legs parallel to each other and overcoming the contrac tion due to the adduction of the liseased leg. ..1bduct ion of the affected
leg is difficult except when the body is flexed to the right side. The trochanter stands high near the crest of the ilium and moves when the leg is moved. Measurement in the recumbent position discloses a 7 cm. shortening of the left leg, which cannot be adducted or entirely straight ened out. Rotation and flexion are free, passive motions arc painless, and no resistance is palpable beneath the artery. The child can jump with the sound right leg, but not with the left, as the foot appears to be fastened to the ground. Diagnosis: Dislocation of the left hip (luxatio iliaea) with shortening and contracture of the left leg.
A comparison of these four cases will enable one to make a more accurate differential diagnosis than could be formed by eitunierating the different points.
If possible a radiograph should always he taken, as it will reveal the shape of the bony acetabulum, the form of the head, and the position of the head to the acetabulum. But we must bear in mind the possi bilities of mistakes in regard to 1. The shape and size of the fibrous acetabulum (fibrous hyperplasia of the acetabular fundus), because fibrous tissue does not throw any shadow.
2. The form of the head and neck in case the legs are not stretched out parallel to each other and in ease both patellae do not face upward. These conditions distort, the picture and give a false idea regarding the position of the head, neck, and shaft. The only possible way to form a definite opinion of the extent of antetorsion is by radiographs taken with the legs in inward rotation (Figs. 49d, 49e, Plate 7).
3. The relation of the head to the acetabulum. A displacement in the sagittal plane is not disclosed in a radiograph.
Caution should be exercised in making a diagnosis of dislocation in infants from the radiograph. In the first place the epiphyses which are car tilaginous throw no shadow in comparison with the ends of the diaphyses. There is also a slight difference in the height of the articulating bodies.