The _congenital variety_ of coxa vara is due to various intra-uterine conditions, of which the chief is defective development of the upper end of the femur; as it does not manifest itself until the child begins to walk, the resemblance to congenital dislocation of the hip is very close. #Coxa Valga.#--Coxa valga is the reverse of coxa vara, the angle at the neck of the femur being over 140°. It is not nearly so important in practice as coxa vara. It may result from incomplete fractures or epiphysial separations, rickets, or various forms of osteomyelitis, but it is also a frequent accompaniment of other deformities, such as congenital dislocation of the hip and paralysis following anterior poliomyelitis. It is commoner in boys than in girls, and is more often single than bilateral. The limb is lengthened, abducted, and rotated outwards; there is flattening of the buttock, and the trochanter is depressed so that it lies below Nélaton's line. The patient is unable to adduct the limb, and shows a peculiar gait, which has frequently caused the condition to be mistaken for unilateral congenital dislocation at the hip. In recent cases it may be possible under anæsthesia forcibly to adduct the limb and rotate it inwards, and to retain it in this position with a plaster bandage. In advanced cases the length of the limbs may be equalised by a high sole on the sound side, or by performing an osteotomy through the great trochanter. THE REGION OF THE KNEE #Congenital dislocation# at the knee-joint is rare; it is usually incomplete, and the patella is sometimes absent. The dislocation may be permanent, or may only occur from accidental movements of the limb. In some cases it can be produced at will by the patient or the surgeon. We have observed one such case in a professional cyclist in whom this capacity of partially dislocating the knee entailed no disability. When the child begins to walk, an apparatus which will prevent hyper-extension and lateral motion should be fitted to the limb. #Congenital absence of the patella# usually complicates other abnormalities of the knee-joint. The tubercle of the tibia is prominent and the extensor tendon unusually thick. In flexion the tendon rises on to the lateral condyle of the femur. #Congenital Dislocation of the Patella Laterally.#--This may be persistent or intermittent. In the _persistent form_ the dislocation is present from birth; the patella rests on the trochlear surface of the lateral condyle, and when the knee is flexed may pass farther outwards and become completely dislocated, lying against the lateral aspect of the condyle.