Patent Application
20120071933
The present invention is directed to systems for affixing a stratum to bone.
The present disclosure relates to retaining mechanisms, and more particularly, systems for affixing a stratum to bone.
A retaining mechanism for use in affixing a stratum to bone is disclosed. The retaining mechanism comprises a stratum and a retaining element. The stratum comprises a first surface, a second surface, and at least one hole extending between the first surface and the second surface, wherein the second surface is configured to engage at least a portion of the bone. The retaining element is configured to engage the stratum and configured to at least partially overlap the at least one hole such that the retaining element helps prevent inadvertent backing out of the fastener after the fastener has been fully inserted into the at least at least one hole of the stratum, wherein the retaining element is substantially rigid.
In other embodiments, a system for affixing a stratum to bone is disclosed. In such embodiments, the system comprises a stratum, a retaining element and a fastener. In such embodiments, the stratum comprises a first surface, a second surface, and at least one hole extending between the first surface and the second surface, wherein the second surface is configured to engage at least a portion of the bone. In such embodiments, the retaining element is configured to engage the stratum and configured to at least partially overlap the head of the fastener such that the retaining element helps prevent inadvertent backing out of the fastener after the fastener has been fully inserted into the at least one hole of the stratum, wherein the retaining element is substantially rigid. In such embodiments, the fastener is configured to pass at least partially through the at least one hole and configured to engage the at least a portion of the bone, wherein the fastener further comprises a head portion configured for manipulation by a user and a shaft portion configured to engage at least a portion of bone.
Further, methods of implanting a spinal plate are disclosed.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments, or examples, illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates.
The term “substantially” as used herein may be applied to modify any quantitative representation which could permissibly vary without resulting in a change in the basic function to which it is related. For example, a retaining element 60 may be considered substantially rigid if when it is in its fully-inserted position and at least partially overlapping a hole, for example, 22 or 24, it does not deflect enough to allow a fastener, for example, 42 or 44, to inadvertently back out of the stratum 20.
As shown in
sufficient force, the retaining element 60 may be removed from the stratum 20 by pulling it out of the stratum 20 in the direction opposite that from which it was inserted into the stratum 20. When the need for removal of retaining element 60 arises, one way is to apply pressure to the legs 62 and 64 in the direction opposite from which it was inserted and away from surfaces 20X and 20Y, respectively. As one would be separating the retaining element 60 from the stratum 20, the stratum 20 or portion thereof may be used as a base from which pressure may be applied to the legs 62 and 64, for example, by prying the legs 62 and 64 away from the stratum 20.
Although the retaining element 60 is shown as having a U-shape, the retaining element 60 may have different shapes, for example a substantially straight length of material such as a rod. That is, the retaining element 60 may take any form that satisfies its function described herein, for example, being able to adequately engage with the stratum 20 and being substantially rigid so that when it is in its fully-inserted position and at least partially overlapping a hole 22 or 24, it does not deflect enough to allow the fastener 42 or 44 to inadvertently back out of the stratum 20.
element 60 is in its fully-inserted position such that the retaining element 60 helps prevent inadvertent backing out of the fasteners 42 and 44. Specifically, as shown in
Although the retaining element 60 is shown as at least partially overlapping the heads 42H and 44H of fasteners 42 and 44, the retaining element 60 may overlap a portion of the fastener or fasteners 42 and 44 other than the heads 42H and 44H. For example, the retaining element 60 may at least partially overlap a portion of a fastener or fasteners 42 and 44 situated lower (or more distal along the fastener) than the heads. In such case, for example, the retaining element 60 may engage a portion of the head 42H and 44H, for example, grooves (not shown) in the heads 42H and 44H provided to engage with the retaining element 60, to thereby help prevent inadvertent backing out of the fastener or fasteners 42 and 44 after the fastener or fasteners 42 or 44 have been fully inserted into the holes 22 and 24 of the stratum 20.
As shown in the Figures and as described herein, the bone may be, for example, part of a spine such as a vertebral body or vertebral bodies, the stratum 20 may be, for example, a spinal plate, and the fastener may be, for example, a screw.
Implantation of a spinal plate 20 may, for example, comprise the following steps: (1) positioning a retaining element 60 in the spinal plate 20 so that it is engaged with the spinal plate 20, but that the retaining element 60 is not in its fully-inserted position so that the retaining element 60 does not block insertion of the fasteners 42 and 44 into the holes 22 and 24 on the plate 20, for example, as shown in
In the embodiments described here, the stratum 20 may be made of a variety of biocompatible materials (metal or non-metal), including but not limited to, Titanium Alloys, commercially available Titanium, stainless steel, polyetheretherketone (“PEEK”), cobalt chrome (“CoCr”), polyetherketoneketone (“PEKK”), ultra high molecular weight polyethylene (“UHMWPE”), polyethylene, shape memory metals, other polymers or any combination of such materials. Similarly, the retaining element 60 and/or the fasteners 42 and 44 may be made of the same materials. Also, any suitable materials know in the art may work for each of these elements.
Whatever material or materials are used to make the retaining element 60, the retaining element 60 described herein is substantially rigid so that when it is in its fully-inserted position and at least partially overlapping a hole 22 or 24 and/or head 42H or 44H of a fastener 42 or 44, it does not deflect enough to allow the fastener 42 or 44 to inadvertently back out of the stratum 20. In this regard, for example, the retaining element 60 may consist essentially of PEEK or may consist essentially of metal.
All adjustments and alternatives described above are intended to be included within the scope of the invention, as defined exclusively in the following claims. Those skilled in the art also should realize that such modifications and equivalent constructions or methods do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure. Furthermore, as used herein, the terms components and modules may be interchanged. It is understood that all spatial references, such as “superior,” “inferior,” “anterior,” “posterior,” “outer,” “inner,” and “perimeter” are for illustrative purposes only and can be varied within the scope of the disclosure.
