A modular, adjustable, prosthetic hip/shoulder spacer adapted to being implanted in the hip or shoulder joint; the spacer comprises a frame that supports a rotatable cylinder from which a neck extends with the ball element of the joint attached to its end, and rotating the cylinder reposition the ball in the socket; the stem is connected to the base of the frame and is implanted in the long bone (femur or humerus); the stem may be modified to include a system for delivering medication to the implantation site following surgery. The stem leg and stem base may be modified to form a modular unit to adjust the relation between a center line of the stem leg and a center line of the frame and position of the neck and ball.