[Illustration: FIG. 130.--Congenital Dislocation of Left Hip in a girl æt. 8. The patient is putting the whole weight on the dislocated limb.]
_Clinical Features._--The condition rarely attracts attention until the child begins to walk, but sometimes the unusual breadth of the pelvis, the presence of a lump in the buttock, snapping about the hip, or a peculiar way of holding the limb, leads the parents to seek advice early. In _unilateral cases_, when the child has learned to walk at the late age of two, three, or it may even be four years, it is noticed that the back is hollow and the buttocks unduly prominent, and that there is a peculiar and characteristic limp; each time the weight of the body is put upon the affected limb, the trunk makes a sudden dip towards that side. There is no pain on walking. The affected limb is shortened, as is shown by the projection of the great trochanter above Nélaton's line; the shortening gradually increases, and in time may amount to several inches. It is partly compensated for by resting the affected limb on the balls of the toes and flexing the knee on the sound side. The gluteal fold is shorter, deeper, and higher than on the healthy side, and on account of the obliquity of the pelvis the spine shows a lateral curvature, with its concavity to the affected side. The movements at the hip-joint are free in all directions except abduction; on practising external rotation it is often found to be abnormally free; lastly, in young children, if the pelvis is fixed, the head of the bone may be made to glide up and down on the ilium.
_In bilateral cases_ the trunk appears well grown in contrast to the short lower limbs, the hollow of the back is exaggerated, the abdomen protrudes, the perineum is broadened, and the buttocks are unduly prominent. The gait is waddling like that of a duck, the trunk lurching from one side to the other with each step. In untreated cases the deformity and disability become more pronounced as the capsular and round ligaments are further stretched, the shortening and limp become more marked, the patient is easily fatigued by walking or standing, and is usually unfitted for earning a living. We have had under observation, however, an adult male with bilateral dislocation and extroversion of the bladder, who efficiently performed the duties of a carrier for many years.