Abstract: A finger prosthesis includes a first screw to be received in an intramedullary canal of a phalange. The first screw includes a first head defining a first longitudinal bore therein. There is provided a second screw to be received in an intramedullary canal of another, adjoining phalange. The second screw includes a second head defining a second longitudinal bore therein. The prosthesis further has a first joint part having a convex semi-cylindrical surface, a transverse slot and a bore hole, a pivot pin held in the bore hole and traversing the transverse slot. The first piston is secured to the pivot pin for swinging motion in the transverse slot. The first piston is received in the first longitudinal bore for sliding motions therein. There is further provided a second joint part situated between the first head and the first joint part and having a concave semi-cylindrical surface slidingly contacting the convex semi-cylindrical surface of the first joint part.