Abstract: A knee joint prosthesis comprises cooperating femoral and tibial components and a coupling which is arranged to make a hinged connection therebetween. Interdisposed hinge knuckles and a cooperating pintle define a lateral-medial pivot axis that is located posteriorly of the intersection between the intermedullary femoral and tibial axes. A pair of transverse confronting plateaus transmit vertical load forces between the elements of the prosthesis. A proximal-distal axle and a cooperating tubular bearing afford rotational motion, and this motion is limited by a stop system, which system is also arranged to permit restricted distraction.