Apart from Foerster's operation, or when it has failed, the spasm of any individual muscle or group of muscles may be got rid of by diminishing the nerve supply to the muscle or by lengthening the tendon. Diminishing the nerve supply was suggested by Stoffel; it consists in exposing the motor nerve as it enters the muscle and resecting one-third or one-half of the fibres so as to reduce the innervation to the required degree. The method is still on its trial. _Lengthening the Tendons._--In spastic paraplegia, for example, Jones resects the origins of the adductors longus and brevis, lengthens the tendo Achillis, divides the popliteal fascia and hamstrings, and transplants the biceps into the quadriceps; after which the limbs are put up in the attitude of wide abduction for six weeks. It is important that the patient should begin to walk with the legs wide apart and learn to balance himself without any feeling of insecurity; he should be taught to look at an object straight in front of him rather than on the ground. THE LOWER EXTREMITY CONGENITAL DISLOCATION OF THE HIP This is the commonest of all congenital dislocations. Its frequency varies in different countries, being greater on the continent of Europe than in this country. It is more often unilateral than bilateral (about 4 to 1), and is about three times more common in girls than in boys. The dislocation takes place in the early months of intra-uterine life, and may be associated with deficiency of the liquor amnii. #Pathological Anatomy.#--_In the infant_, the anatomical changes in the joint are less marked than they are after the child has borne its weight on the limb. The acetabulum, never having been occupied by the head of the femur, is imperfectly developed; it remains flat and shallow, is partly filled with fibro-fatty tissue derived from the synovial membrane, and is always too small for the head of the femur. The cotyloid ligament being broader and thicker than usual, makes the osseous portion of the socket appear deeper than it really is. In unilateral cases the affected half of the pelvis is contracted, so that the pelvic basin is narrowed and oblique. The head of the femur is small, flattened, and, in some cases, conical; and the angle formed by the neck with the shaft is altered, sometimes diminished, it may be to a right angle--_coxa vara_ (Fig. 129); sometimes increased--_coxa valga_. There is also a variable degree of torsion of the neck, ante-torsion being of practical importance as it increases the difficulty of retaining the head in the socket. The capsule is lax and admits of the head passing upwards for a variable distance on to the dorsum ilii. In unilateral cases the ligamentum teres is elongated and thickened; in bilateral cases it is frequently absent. [Illustration: FIG. 128.--Radiogram of Double Congenital Dislocation of Hip in a girl æt. 4.]