The SB Charité intervertebral disc prostheses consist of two metal end-plates and an interposed polyethylene slide core. These were subjected to static and dynamic testing in a servohydraulic test rig. When embedded in polypropylene, the prostheses were found to function adequately under a high static load, and under a lighter dynamic load for a long time. When tested in a cadaveric vertebral segment, a large end-plate surface area proved to be of critical importance in preventing collapse of the prosthesis into the vertebral body.