A unitary acetabular cup prosthesis for a deficient acetabulum of a hip bone having a cup portion and a pair of adjacent screw retaining members extending from the cup and oriented in a cooperative with one another. A second pair of screw retaining members are preferably provided, with the first and second pair of screw retaining members oriented such that the prosthesis can be used in either a left or a right acetabulum of the patient. The screw retaining members may be formed on a single flange. The screw retaining members are fixedly inclined and offset relative to the rim of the cup. Each screw retaining member has a threaded hole inclined relative to the rim such that an axis of the threaded hole converges toward the axis of the cup portion in one dimension and is oblique to the axis of the cup portion in a second dimension.