Multizone Implants
Medical devices having more than one degradation zone or degradation mechanism are used for orthopedic repair devices and soft tissue fixation devices.
1 . An implant comprising at least two degradation zones having different degradation rates, the at least two degradation zones including a first degradation zone at a distal portion of the implant and a second degradation zone at a proximal portion of the implant.
2 . The implant according to claim 1 , further comprising a third degradation zone at an intermediate portion of the implant, the intermediate portion being located between the distal portion and the proximal portion of the implant.
3 . The implant according to claim 1 , wherein the first degradation zone has a faster degradation rate than the second degradation zone.
4 . The implant according to claim 2 , wherein the first degradation zone has a faster degradation rate than the third degradation zone and the third degradation zone has a faster degradation rate than the second degradation zone.
5 . The implant according to claim 1 , wherein the first degradation zone comprises a different composition than the second degradation zone.
6 . The implant according to claim 1 , wherein the first degradation zone comprises a composition that is the same as a composition of the second degradation zone.
7 . The implant according to claim 1 , further including an osteoconductive inorganic phase.
8 . The implant according to claim 1 , further comprising an interface between the first degradation zone and the second degradation zone.
9 . The implant according to claim 2 , further comprising an interface between at least one of the first and third degradation zones and the third and second degradation zones.
10 . The implant according to claim 1 , further comprising an interphase between the first degradation zone and the second degradation zone.
11 . The implant according to claim 2 , further comprising an interphase between at least one of the first and third degradation zones and the third and second degradation zones.
12 . The implant according to claim 1 , wherein the composite implant may be selected from the group consisting of orthopedic repair devices and soft tissue repair devices.
13 . The implant according to claim 1 , wherein the implant is a bone anchor.
14 . The implant according to claim 1 , wherein the degradation zones comprise materials selected from the group consisting of polyesters, polyester polyalkylene oxide copolymers, polyorthoesters, polyhydroxybutyrates, polyhydroxyalkanoates, polyanhydrides, polyamines, polycarbonates, copolymers and combinations thereof.
15 . The implant according to claim 1 , wherein at least one degradation zone comprises a porous structure.
16 . The implant according to claim 1 , wherein the first degradation zone comprises more amorphous regions than the second degradation zone.
17 . The implant according to claim 1 , wherein the second degradation zone comprises more crystalline regions than the first degradation zone.
18 . The implant according to claim 1 , further comprising a bioactive agent.
19 . The implant according to claim 1 , wherein at least one degradation zone comprises a polymer drug.
20 . The implant according to claim 1 , wherein the degradation rate of at least one degradation zone corresponds to an elution of a bioactive agent.