Patent Application
20070299441
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
Referring to
The occipital plate 10 according to this embodiment of the invention includes a base plate 26 having an elongate central section 28 with a midline 30, which is generally aligned with the spine when mounted to the occipital bone 14. The central section 28 may include a number of holes or apertures 32, three of which are shown, for bone screws 34 to mount the occipital plate 10 to the occipital bone 14 or another portion of the patient 16. The occipital plate 10 is generally symmetric relative to the midline 30 and includes a pair of lateral sections 36 projecting laterally outward in opposite directions from the midline 30. Each lateral section 36 is joined to the central section 28 via an angled transition section 38 that may include a hole or aperture 40 to receive a bone screw 34 there through for an additional mounting location to the occipital or other bone. The lateral sections 36 extend laterally in a direction generally perpendicular to the midline 30 of the central section 28.
As shown generally in
In one embodiment, each rod attachment assembly 42 includes a channel-shaped slide member 44 having an upper wall 46 and a pair of spaced sidewalls 48 projecting generally perpendicularly from the upper wall 46. A distal end of each slide member 44 includes an end cap 50 and each sidewall 48 includes a triangular-shaped extension 52 projecting inwardly toward the opposing sidewall 48. Each slide member 44 also includes a generally cylindrical boss 54 projecting upwardly from the top wall 46 of the slide member 44 opposite from the end cap 50. A post 56 extends upwardly from the top wall 46 of the slide member 44 at a location spaced between the end cap 50 and the boss 54. The post 56 has a semi-circular cross-section and includes an arcuate convex-shaped trunk portion 58 confronting an arcuate convex-shaped skirt 60 of the boss 54. The trunk 58 and skirt 60 combine to form an arcuate-shaped well 62 into which the rod 18 of the OCT construct 12 is received.
The rod 18 is clamped to the attachment assembly 42 and, as a result, the occipital plate 10 by a set screw 64 and cam lock 66 as shown specifically in
A lug 76 projects from the cam lock 66 toward the post 56 and in combination with the well 62 formed by the trunk 58 and the skirt 60 secures the rod 18 to the attachment assembly 42. The distal end of the shaft 68 of the set screw 64 is juxtaposed against the upper face of the lateral section 36 of the base plate 26 as shown in
The spaced side edges of each lateral section 36 of the base plate 26 each include a triangular-shaped groove 78 adapted to mate with one of the extensions 52 projecting from the sidewall 48 of the slide member 44 thereby forming a dove-tail joint construct between the attachment assembly 42 and the base plate 26 (
Therefore, the occipital plate 10 according to this invention provides for medial lateral adjustability when attaching the rods 18 as part of an OCT construct 12. The surgeon only needs to tighten one set screw 64 for each attachment assembly 42 to lock the rod 18 and the position of the attachment assembly 42 relative to the midline 30 of the occipital plate 10. Those of ordinary skill in the art will readily appreciate that other attachment assemblies and mechanisms can be utilized within the scope of this invention for securing the position of the rod relative to the midline of the occipital plate. Likewise, other geometries and configurations of the base plate are readily envisioned within the scope of this invention.
The attachment assembly may be securely and selectively mounted to the occipital plate at a variety of positions and locations on the lateral section of the base plate thereby providing for a wide range of compatibility for a variety of patient geometries, sizes and physical dimensions. Additionally, the attachment assemblies are easily and quickly secured and adjusted by the surgeon during installation of the occipital plate and OCT construct thereby minimizing surgical time and trauma to the patient. Moreover, the respective attachment assemblies can be individually positioned relative to the midline depending on the particular requirements and demands of the OCT construct and installation procedure. In other words, each of the attachment assemblies do not need to be the same distance from the midline to thereby accommodate unique geometries and installation requirements without additional inventory.
From the above disclosure of the general principles of the present invention and the preceding detailed description of at least one preferred embodiment, those skilled in the art will readily comprehend the various modifications to which this invention is susceptible. Therefore, we desire to be limited only by the scope of the following claims and equivalents thereof.
