| 摘要 |
<p>The invention describes a dynamically lubricated total joint prosthesis having: (1) at least one of the two articulating members (the ball and/or the cup of the hip prosthesis) moveably supported on the bone-anchored part of the prosthesis; and (2) at least one fluid filled compartment connected to the interarticular gap, wherein the load induced movement of the articulating member(s) relatively to its (theirs) bone-anchored part(s) causes a pressure increase in the fluid filled compartment and forces the fluid into the articular gap. When the load on the joint is reduced the fluid compartment increases its volume due to elastic restoring force and refills with the fluid. The flow of the fluid is controlled by a load-dependent flow restriction which increases under high load - when the fluid is expressed - and decreases when the load is reduced - during the refill phase. In this way the fluid balance can be maintained in spite of very high pressures - on the order of 5MPa - expressing the fluid, and no more than - 0.1 MPa sucking the fluid back. This lubrication mechanism mimics that of the 'weeping' of natural cartilage.</p> |
