HIP-JOINT, CONGENITAL DISLOCATION OF.—A malformation of the hip-joint, in which the head of the thigh-bone, instead of being situated in its socket in the pelvis, is placed outside the socket, either in front of it or behind. The deformity may affect one or both sides ; and girls are more frequently afflicted than boys. If the defect be not treated it results in marked disturbances of walking. A one-sided dislocation (see Fig. 228) makes one leg shorter than the other—sometimes very considerably so—and the patient limps very‘ conspicuously. A dislocation of both sides (see Fig. 229) does not produce a limp, as both legs are affected equally. The walk, however, becomes clumsy and waddling, because the heads of the thigh bones are not supported in their sockets. The pelvis is depressed, the lumbar region of the back becomes hollow, and the projecting heads of the thigh-bones form humps on the buttocks. Patients suffering from dislocation of the hip-joint are unable to walk very much ; they tire readily even if they suffer no pain.
Formerly it was not thought possible to do much toward relieving this condition, and treatment was restricted to the wearing of thick-soled shoes and of corsets and apparatus. At the present time, how
ever, the defect is treated operatively, usually by the so-called " bloodless " operation, which consists in reducing the dislocation by manual 'strength (the patient being under the influence of an am:esthetic), whereupon the limb is placed in a plaster of7Paris cast to hold it in position. It is desirable to correct the deformity as early as the first or second year ; and the parents of a child that limps should not delay to have it examined by a physician. In some cases an open operation will be found necessary, but only a surgeon is able to decide this point.
It should be remembered that a normal gait is not always obtained. Improvement is the rule. Complete success is sometimes rendered impossible by the structure of the head of the thigh-bone, and by the circumstance that the socket is too small to hold the head of the bone.