The spherical-head prosthesis offers a new type of hip reconstruction. Intramedullary anchorage by a threaded stem, as provided by the door-knob type of prosthesis devised by the author, has proved generally satisfactory in twenty-two cases. Complications have been of minor consequence. This type of prosthesis is especially dependable when the major portion of the femoral neck is absent and when there is lack of good bone texture in the trochanter.