摘要 |
Disclosed are endoprostheses which include a piston forming a joint head and mounted on a bone and a cylinder for receiving the piston and mounted in the mating bone. The cylinder is divided into two sections, the section for receiving the piston contains a liquid, advantageously in bellows, which liquid is forced into the other section of the cylinder to compress a gas, the compressed gas therein thereby cushioning shocks. Flow of liquid between the sections is controlled by back pressure valves. |