Cross-linked ultra-high molecular weight polyethylene for medical implant use
AssigneeSmith & Nephew, Inc.
InventorsMarcus L. Scott, Shilesh C. Jani
Life of this patent
Estimating the term…
Abstract
The present invention relates to the prevention and decrease of osteolysis produced by wear of the ultrahigh molecular weight polyethylene (UHMWPE). Methods are disclosed for the isolation of wear particles, preparation of implants exhibiting decreased wear in comparison to conventional UHMWPE and preparation of implants that cause decreased biological response in comparison to conventional UHMWPE. The implants created by these methods are also included in the present invention.
Claims195
A method for isolating wear particles from an ultrahigh molecular weight polyethylene (UHMWPE) medical implant for use in the body comprising the steps of:
- crosslinking the UHMWPE;
- annealing the UHMWPE;
- machining UHMWPE to form an implant;
- wear testing the implant;
- harvesting wear particles;
- and
- filtering the particles using 0.05 μm or smaller pore size filters.
A method of preparing an UHMWPE medical implant for use in the body having a decreased wear particle number comprising the steps of:
- crosslinking the UHMWPE;
- annealing the UHMWPE;
- and
- machining UHMWPE to form an implant;
- wherein the wear particles that are decreased in number are greater than 0.125 μm in diameter.
A method of decreasing macrophage response to an UHMWPE medical implant for use in the body comprising the steps of:
- performing wear particle analysis;
- and
- crosslinking the UHMWPE at a dose level exhibiting the lowest particle number per million cycles of the hip simulator wherein the number of particles present was determined using a 0.05 μm or smaller pore size filter.
A method of decreasing macrophage response to an UHMWPE medical implant for use in the body comprising crosslinking UHMWPE prior to implantation in a patient wherein the total volume of wear particles is decreased and the total number of wear particles is decreased.
A method of decreasing macrophage response to an UHMWPE medical implant for use in the body comprising the steps of:
- crosslinking the UHMWPE;
- annealing the UHMWPE;
- machining UHMWPE to form an implant;
- wear testing the implant;
- harvesting wear particles;
- filtering the particles using 0.05 μm pore or smaller size filters;
- characterizing the wear particles;
- determining the number of particulate debris;
- and
- selecting the crosslinking method for implants that gives the lowest number of particulate debris.
A method of decreasing macrophage response to an UHMWPE medical implant for use in the body comprising the steps of:
- crosslinking the UHMWPE;
- annealing the UHMWPE;
- machining UHMWPE to form an implant;
- wear testing the implant;
- harvesting wear particles;
- filtering the particles using 0.05 μm or smaller pore size filters;
- characterizing the wear particles;
- determining the number of particulate debris;
- determining the total particle surface area;
- and
- selecting the crosslinking method for implants that gives the lowest total particle surface area.
A method of decreasing osteolysis of an UHMWPE medical implant for use in the body comprising the steps of:
- crosslinking the UHMWPE;
- annealing the UHMWPE;
- machining UHMWPE to form an implant;
- wear testing the implant;
- harvesting wear particles;
- filtering the particles over 0.05 μm or smaller pore size filters;
- characterizing the wear particles;
- determining the number of particulate debris;
- and
- selecting the crosslinking dose level to crosslink implants that exhibits the lowest number of particulate debris.
A method of decreasing osteolysis of an UHMWPE medical implant for use in the body comprising the steps of:
- crosslinking the UHMWPE;
- annealing the UHMWPE;
- machining UHMWPE to form an implant;
- wear testing the implant;
- harvesting wear particles;
- filtering the particles using 0.05 μm or smaller pore size filters;
- characterizing the wear particles;
- determining the number of particulate debris;
- determining the total particle surface area;
- and
- selecting the crosslinking method for implants that gives the lowest total particle surface area.
A method of decreasing macrophage response to a UHMWPE medical implant for use in the body comprising the steps of crosslinking the UHMWPE, simulating use in a host, and testing serum for particulate debris using a 0.05 μm pore size filter, wherein particles of the diameter of 0.1 μm to 1 μm cause increased macrophage response.
A crosslinked UHMWPE medical implant for use in the body that exhibits decreased osteolysis (or macrophage response) in comparison to conventional treatment of UHMWPE due to a particle number of less than 5×1012 per year upon testing for wear resistance.
An UHMWPE medical implant for use in the body having a decreased wear particle number of particles created by the steps comprising of:
- crosslinking the UHMWPE;
- annealing the UHMWPE;
- machining UHMWPE to form an implant;
- wear testing the implant;
- harvesting wear particles;
- filtering the particles over 0.05 μm or smaller pore size filters;
- characterizing the wear particles;
- determining the number of particulate debris;
- and
- selecting the crosslinking method to crosslink implants that exhibits the lowest number of particulate debris;
- wherein the wear particles that are decreased in number are greater than 0.125 μm in diameter.
Dependencies are inferred from the claim text.