Abstract: A prosthesis has a ceramic part to cooperate with a spherical head. This ceramic part is a ring whose inside surface is part of a sphere. The prosthesis is suitable for coxofemoral joints.

Abstract: The femoral part (15) is, for example, of the kind comprising two lateral branches (16) each adapted to be applied to a respective condyl of the femur to be treated, to cooperate with the glenes of the corresponding tibial plates, and a median part (20) to which the aforementioned lateral branches (16) are joined.According to the invention, at least part of the rubbing surface of the femoral part (15) is provided with a ceramic facing (22); for example, this applies to each of its lateral branches (16) over part at least of their length.Application to full knee prostheses.

Abstract: A joint prosthesis comprises two pins each designed to be directly or indirectly inserted into a respective one of the two bones to be joined. Operative between the pins are articulation surfaces comprising, in the case of one of the pins, referred to as the carrier pin, two domes centered on an axis perpendicular to the carrier pin, oriented in opposite directions relative to each other and carried by the carrier pin. In the case of the other pin, referred to as the carried pin, the articulation surfaces comprises two further domes each complementary to a respective one of the first-mentioned domes, and thus adapted to be engaged therewith, carried by the carried pin. The domes of the carrier pin are carried by respective pegs which are movable transversely relative to the two pins, the carrier pin comprising two arms each having two respective aligned housings in which the pegs are slidably inserted.

Abstract: A method and apparatus for stimulating a heart to eliminate rhythmic abnormalities, especially tachycardias. In accordance with a method of orthorhythmic stimulation, the electric stimulation is applied after a delay period following a natural electrosystole. The electric stimulation comprises a train of pulses, preferably between three and twenty, which straddles the end of the delay period. Such trains of pulses may also alternate with one or more trains of a single pulse. The stimulator comprises a trigger responsive to the natural electrosystole of the heart, a first counter of predetermined frequency and a second counter of adjustable higher frequency serially connected to the first counter for driving a pulse generator generating the trains of pulses.