Numerous joint replacement implant embodiments including a total knee replacement implant including a femoral component (102) having a wheel (104); and a tibial component (106) including a shock-adsorbing component with a piston assembly (110) and spring (112). Said implants contain a cushioning or shock-absorbing member to dampen axial loads and other forces. In many embodiments, fluid is force rapidly from the device wherein compression and dampening is achieved by valves or other pathways that allow for a slower return of the fluid back into the implant as the pressure is relieved.