Demineralized bone implants
View Patent ↗Selectively demineralized bone-derived implants are provided. In one embodiment, a bone sheet for implantation includes a demineralized field surrounding mineralized regions. In another embodiment, a bone defect filler includes a demineralized cancellous bone section in a first geometry. The first geometry is compressible and dryable to a second geometry smaller than the first geometry, and the second geometry is expandable and rehydratable to a third geometry larger than the second geometry.
1. A method of providing a bone implant comprising:
demineralizing a block of cancellous bone having a first geometry;
wetting the block;
compressing the block from the first geometry to a second geometry smaller than the first geometry;
hardening the block after the block has been compressed to the second geometry; and
re-expanding the block to a third geometry larger than the second geometry.
2. The method of claim 1 , wherein the second geometry is configured and dimensioned as a pellet.
3. The method of claim 1 , wherein the second geometry is configured and dimensioned as a cylinder.
4. The method of claim 1 , wherein the second geometry is configured and dimensioned as a generally flat shape.
5. The method of claim 1 , wherein the second geometry is configured and dimensioned as a donut-like shape.
6. The method of claim 1 , wherein the second geometry is configured and dimensioned as a dumbbell shape.
7. The method of claim 1 , further comprising:
exposing the block to a swelling agent.
8. The method of claim 7 , wherein the swelling agent is water.
9. The method of claim 1 , further comprising:
inserting the block into an anatomical space.
10. The method of claim 1 , wherein the hardening step includes drying the block.
11. The method of claim 1 , wherein the re-expanding step includes hydrating the block.
12. A method of providing a bone implant comprising:
demineralizing a block of cancellous bone having a first geometry;
wetting the block;
compressing the block from the first geometry to a second geometry smaller than the first geometry;
hardening the block after the block has been compressed to the second geometry; and
inserting the block into a spinal cage.
13. The method of claim 12 , further comprising:
re-expanding the block in the spinal cage to a third geometry larger than the second geometry.
14. The method of claim 13 , wherein the third geometry is smaller than the first geometry.
15. The method of claim 12 , wherein the step of wetting the block comprises hydrating the block.
16. A method of providing a bone implant comprising:
demineralizing a block of cancellous bone having a first geometry;
softening the block so that the block may be compressed from the first geometry to a second geometry smaller than the first geometry;
permitting the block to harden after the block has been compressed to the second geometry;
inserting the block into a cavity; and
re-expanding the block to a third geometry larger than the second geometry, wherein the third geometry is cylindrical in shape.
17. The method of claim 16 , wherein the step of softening the block comprises applying a swelling agent to the block.
18. The method of claim 17 , wherein the swelling agent is water.
19. A method of providing a bone implant comprising:
demineralizing a block of cancellous bone having a first geometry;
softening the block so that the block may be compressed from the first geometry to a second geometry smaller than the first geometry;
permitting the block to harden after the block has been compressed to the second geometry;
inserting the block into a cavity; and
re-expanding the block to a third geometry larger than the second geometry, wherein the cavity is defined by a spinal cage.
20. The method of claim 19 , wherein the spinal cage includes perforations and the third geometry of the expanded block fills at least part of the cavity and at least some of the perforations.
21. A method of preparing a bone implant comprising:
demineralizing a block of cancellous bone having a first geometry;
hydrating the block so that the block may be compressed from the first geometry to a second geometry smaller than the first geometry;
dehydrating the block;
inserting the dehydrated block into a hollow cage; and
re-expanding the block to a third geometry larger than the second geometry.
22. The method of claim 21 , wherein the step of dehydrating the block includes hardening the block.
23. The method of claim 21 , wherein the second geometry has a pellet-like shape.
24. The method of claim 21 , wherein the re-expanding step includes wetting the block with a swelling agent.
25. The method of claim 24 , wherein the swelling agent is water.
26. The method of claim 21 , wherein the hollow cage is a spinal cage.
27. The method of claim 21 , wherein the hollow cage has a cylindrical shape defining a cavity therein.
28. The method of claim 21 , wherein the hollow cage includes perforations and the third configuration of the expanded block fills at least some of the perforations.
29. The method of claim 21 , wherein the dehydrating step includes freeze drying the block.
30. The method of claim 21 , wherein the second geometry has a pellet-like shape.