1. The shelf operation for stabilization of the hip is indicated for congenital dislocation of the hip in children and young adults when the symptoms justify the operation and the dislocation cannot be reduced or reduction is expected to result in a stiff, painful hip with degenerative changes in the bones.
2. Shelf stabilization should be combined with open reduction when the hip remains unstable even after the cartilaginous acetabulum has been reshaped when practical and the redundant portion of the capsule has been freed and removed. The shelf operation is rarely necessary in patients under the age of five years and is usually inadvisable before that age because of the difficulty of getting the shelf low enough, due to the large amount of cartilage in the acetabular roof.
3. Disturbance of the circulation to the femoral head, followed by changes resembling coxa plana and limitation of motion, often with pain, is likely to result from pulling the femur down so that the position is maintained under constant marked tension of the soft tissues about the femoral neck, regardless of the location of the head.
4. The best results were obtained in the cases reported herewith by using a turned-down flap of ilium, blocked in a position perpendicular to the long axis of the body. Good results were obtained in approximately 75 per cent. of the hips on which this type of operation was performed.
5. Early mobilization of the hip is desirable, but weight-bearing should usually be delayed until active control of the hip is reasonably good and the roentgenogram shows the shelf to be sufficiently strong.
6. It is rarely advisable to correct the anteversion by a shelf operation without reduction, as the femoral head is less likely to dislocate beyond the shelf if its relation to the ilium is not disturbed. Similarly, transposition of the femoral head is inadvisable.
7. Shelf stabilization is indicated for selected unstable hips, due to such conditions as infantile paralysis and deformities following suppurative arthritis.