1. Successful closed reductions were obtained in 42 per cent. of 492 hips with congenital dislocation.

2. Successful open reductions were obtained in 77 per cent. of 122 such hips; the results in forty-nine of these hips are here reported for the first time. Good functional results were secured in 78 per cent. of the open reductions.

3. Closed manipulation is the operation of choice for patients in the first year of life and may be attempted in children up to three years of age, but open operation is preferred after the age of two. The shelf-stabilization operation is the most satisfactory operation for most children over six years of age.

4. Traction with adhesive tape before reduction is of little or no value, but may be useful after reduction when there is some tension at the hip.

5. The chief factors in redislocation are the size and shape of the acetabulum and the redundancy of the capsule. The acetabulum should be large enough to allow the head to enter well and move smoothly, and its roof should be round and horizontal rather than oblique. Cartilage may be removed from the roof to accomplish this purpose. The capsule, when adherent, should be freed superiorly and a sufficient section removed to prevent redundancy, and anatomical closure should be secured. Anteversion often favors redislocation and should be corrected when such is the case.

6. The principal causes of postoperative limitation of motion which can be avoided are tension of the tissues about the hip joint, due either to the reduction or to the position of immobilization, damage at the superior acetabular margin, and the presence of a large area of raw bone or raw soft tissue.

7. Coxa plana in congenital dislocations is due to the circulatory disturbance caused by tension upon the capsule and adjacent tissues of the joint, and is almost wholly avoidable.