Demineralized bone-derived implants

Abstract

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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The benefit of Provisional Application No. 60 / 271,745 filed Feb. 28, 2001 is claimed under 35 U.S.C. § 119(e).FIELD OF THE INVENTION [0002] The invention is related to implants formed from bone. More particularly, the invention is related to implants formed from partially demineralized or demineralized bone. BACKGROUND OF THE INVENTION [0003] Bone grafts have become an important and accepted means for treating bone fractures and defects. In the United States alone, approximately half a million bone grafting procedures are performed annually, directed to a diverse array of medical interventions for complications such as fractures involving bone loss, injuries or other conditions necessitating immobilization by fusion (such as for the spine or joints), and other bone defects that may be present due to trauma, infection, or disease. Bone grafting involves the surgical transplantation of pieces of bone Within the body, and generally is effe...

AI Technical Summary

Benefits of technology

The present invention is related to a bone sheet for implantation, which includes a demineralized field surrounding at least one mineralized region. The sheet can be made of cortical bone and has ribs or projections providing localized thickness. The invention also includes a method of forming a flexible bone sheet by creating at least one hole in a cortical sheet and masking the surrounding area to demineralize the sheet. The invention also includes a sheet formed of bone strips with a bone grain orientation, which can be interwoven and have a width and thickness ranging from 1 mm to 6 mm. The invention also includes a bone defect filler that is compressible and dryable to a smaller geometry and expandable and rehydratable to a larger geometry. The filler can be inserted into an open region and allowed to expand to fill the open region.

Problems solved by technology

This is primarily due to the limited applicability of xenografts, transplants from another species.

It is not always possible or even desirable to use an autograft.

Furthermore, the removal of material, oftentimes involving the use of healthy material from the pelvic area or ribs, has the tendency to result in additional patient discomfort during rehabilitation, particularly at the location of the material removal.

Grafts formed from synthetic material have also been developed, but the difficulty in mimicking the properties of bone limits the efficacy of these implants.

Additionally, the strain to failure of cancellous bone is about 5-7%, while cortical bone can only withstand 1-3% strain before failure.

It should also be noted that these mechanical characteristics may degrade as a result of numerous factors such as any chemical treatment applied to the bone material, and the manner of storage after removal but prior to implantation (i.e. drying of the bone).

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