A prosthesis for replacement of a ball and socket joint in the human body. The prosthetic components comprise a plurality of separate parts which may be inserted through a hole in the femur of the patient and assembled and attached to the prepared acetabulum of the hip bone to form a cup-shaped first shell in a minimally invasive surgical procedure. A cup may be passed through the hole in the femur and attached to the first shell to form a socket portion of the joint. The prosthesis may comprise a shaft having a first end with a ball formed thereon that is inserted in the hole through the femur so that the ball engages the cup for movement therein.