The present invention relates to a fixing plate that is used to fixedly attach multiple bones or bone pieces together.
Medical implants are often used to secure adjacent bones or bone fragments together. One potential problem, however, with the screws used to secure an implant in a patient is that, over time, it is possible for the screws to work their way out of the bone, potentially causing pain to the patient and requiring a clinician to either remove or re-insert the screws, which can cause additional pain to the patient and possibly open the patient to risk of infection.
It would be beneficial to provide a fixation assembly that minimizes or eliminates the risk of screws backing out.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
In one embodiment, the present invention is a retaining plate with locking mechanism assembly that includes a retaining plate having a first screw hole extending therethrough and a spring blocker rotatably mounted in plate proximate to the first screw hole. The spring blocker includes a body portion, a first land extending radially from the body portion above the retaining plate, and a first wing extending tangentially from the first land in a first arc. When a first screw is inserted into the first screw hole, when the spring blocker is rotated to a first position, the first land extends over a portion of the first screw. When the spring blocker is rotated to a second position, the first wing extends over the portion of the first screw. When the spring blocker is rotated to a third position, neither the first land nor the first wing extends over the portion of the first screw.
The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate the presently preferred embodiments of the invention, and, together with the general description given above and the detailed description given below, serve to explain the features of the invention. In the drawings:
In the drawings, like numerals indicate like elements throughout. Certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention. The terminology includes the words specifically mentioned, derivatives thereof and words of similar import. The embodiments illustrated below are not intended to be exhaustive or to limit the invention to the precise form disclosed. These embodiments are chosen and described to best explain the principle of the invention and its application and practical use and to enable others skilled in the art to best utilize the invention.
Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term “implementation.”
As used in this application, the word “exemplary” is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word exemplary is intended to present concepts in a concrete fashion.
The word “about” is used herein to include a value of +/−10 percent of the numerical value modified by the word “about” and the word “generally” is used herein to mean “without regard to particulars or exceptions.”
Additionally, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or”. That is, unless specified otherwise, or clear from context, “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then “X employs A or B” is satisfied under any of the foregoing instances. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form.
Unless explicitly stated otherwise, each numerical value and range should be interpreted as being approximate as if the word “about” or “approximately” preceded the value of the value or range.
The use of figure numbers and/or figure reference labels in the claims is intended to identify one or more possible embodiments of the claimed subject matter in order to facilitate the interpretation of the claims. Such use is not to be construed as necessarily limiting the scope of those claims to the embodiments shown in the corresponding figures.
It should be understood that the steps of the exemplary methods set forth herein are not necessarily required to be performed in the order described, and the order of the steps of such methods should be understood to be merely exemplary. Likewise, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments of the present invention.
Although the elements in the following method claims, if any, are recited in a particular sequence with corresponding labeling, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence.
Referring to the Figures, the present invention provides a cervical plating platform with enhanced locking features to prevent implanted screws from backing out after implantation. In an exemplary embodiment, shown in
Retaining plate 150 has a plurality of fixation portions, each fixation portion having a pair of adjacent screw holes 161 formed there in for receiving fixation screws 160.
Spring blocker assembly 100 incorporates a singular locking mechanism with dual functionality. The locking mechanism includes a spring blocker 102, with a locking cam 104 inserted coaxially over spring blocker 102. Spring blocker 102 can be constructed from Nitinol, titanium, stainless steel, or other suitable biocompatible material. Spring blocker 102 is arranged proximate to the pair of screw holes 161 such that spring blocker 102 acts as a retaining device to retain screws 160 in screw holes 161 after screws 160 are inserted into bone.
Spring blocker 102 includes a generally circular central body portion 106 having a through opening 108 formed therein. Through opening 108 is sized and shaped to accept locking cam 104.
Through opening 108 extends downwardly through central body portion 106 and flares outwardly into a frustoconical shaped lower recess 109 to engage a similarly shaped lip 111 in locking cam 104, as shown in
Referring specifically to
A beveled first wing 120 extends tangentially from first land 110 in an arc such that an outer edge 122 of first wing 120 has the same radius of curvature as first arcuate edge 112. First wing 120 extends about 90 degrees around the perimeter of body portion 106. A gap 124 is provided between first wing 120 and body portion 106 so that a free end 126 of first wing 120 can flex relative to first land 110.
Similarly, a beveled second wing 130 extends tangentially from second land 114 in an arc such that an outer edge 132 of second wing 130 has the same radius of curvature as second arcuate edge 116. Second wing 130 extends about 90 degrees around the perimeter of body portion 106 in the same direction as first wing 120. A gap 134 is provided between second wing 130 and body portion 106 so that a free end 136 of second wing 130 can flex relative to second land 114.
A first space 128 is provided between free end 126 of first wing 120 and second land 114. Similarly, a second space 138 is provided between free end 136 of second wing 130 and first land 110. Spaces 128, 138 are sized to allow the heads of screws 160 to be uncovered by spring blocker assembly 100 for removal of screws 160, if desired.
Locking cam 104 includes a generally oblong shaped body 140 with parallel longitudinal sides 142, 144 on either side of a recess 146. In an exemplary embodiment, recess 146 can be for a Torx® head driver, although those skilled in the art will recognize that recess 146 can be shaped to accept other types of drivers.
Sides 142, 144 are sufficiently long such that, when locking cam 104 is rotated to the position shown at “A” in
Spring blocker assembly 100 can be used in a one-step locking process or a two-step locking process. In a one-step locking process, retainer plate 150 is aligned with three adjacent vertebrae 70, 72, 74, as shown in
In a two-step locking process, in addition to the process described immediately above, locking cam 140 is rotated from position “B” in
Referring to
Referring to
Referring to
Spring blocker 300 is similar to spring blocker 102, except that spring blocker 300 includes a pair of diametrically opposing detents 304 that extend from a top 306 of spring blocker 300, along a body 308 of spring blocker 300, to a bottom 310 of spring blocker 300. Detents 304 each engage a protrusion (not shown) in plate 150, 250 to resist rotation of spring blocker 300 in either a clockwise or a counter-clockwise direction. Detents 304 and their associated protrusions are located relative to each other to engage when wings 328, 330 are over the heads 162 of screws 160, restricting the ability of screws 160 to work themselves out of the bone.
Central body portion 502 extends downwardly from blind opening 504 and flares outwardly into a frustoconical shaped lower portion 506 (shown in
A first land 510 extends radially outwardly from body portion 502 and extends over an arc of about 45 degrees. First land 510 has a beveled arcuate first outer edge 512 with a radius of curvature. Similarly, a second land 514 extends outwardly from body portion 502 diametrically across body portion 502 from first land 510. Second land 514 has a beveled second arcuate outer edge 516 with the same radius of curvature as first outer edge 512.
A beveled first wing 520 extends tangentially from first land 510 in an arc such that an outer edge 522 of first wing 520 has the same radius of curvature as first arcuate edge 512. First wing 520 extends about 90 degrees around the perimeter of body portion 502. A gap 524 is provided between first wing 520 and body portion 502 so that a free end 526 of first wing 520 can flex relative to first land 510.
Similarly, a beveled second wing 530 extends tangentially from second land 514 in an arc such that an outer edge 532 of second wing 530 has the same radius of curvature as second arcuate edge 516. Second wing 530 extends about 90 degrees around the perimeter of body portion 502 in the same direction as first wing 520. A gap 534 is provided between second wing 530 and body portion 502 so that a free end 536 of second wing 530 can flex relative to second land 514.
A first space 528 is provided between free end 526 of first wing 520 and second land 514. Similarly, a second space 538 is provided between free end 536 of second wing 530 and first land 510. Spaces 528, 538 are sized to allow the heads of screws 560, 570 to be uncovered by spring blocker assembly 500, as shown in
Referring to
Similar to spring blocker assembly 500, spring blocker assembly 700 has a generally circular central body portion 702 having a blind opening 704 (or, alternatively, a through opening) formed therein. Blind opening 704 is sized and shaped to accept a driver (not shown).
Central body portion 702 extends downwardly from blind opening 704 and flares outwardly into a frustoconical shaped lower portion 706 to engage a recess in a retaining plate, yet allow body portion 702 to rotate freely within the recess, as shown in
Body portion 702 includes a plurality of detents 703 formed around an exterior perimeter of body portion 702. Detents 703 are engaged by protrusions 751 in plate 750 to add an additional locking feature to restrict unwanted rotation of spring blocker assembly 700 with respect to plate 750.
A first land 710 extends radially outwardly from body portion 702 and extends over an arc of about 45 degrees. First land 710 has an arcuate first outer edge 712 with a radius of curvature. Unlike spring blocker assembly 500, spring blocker assembly 700 has no second land.
A first wing 720 extends tangentially from first land 710 in an arc such that an outer edge 722 of first wing 720 has the same radius of curvature as first arcuate edge 712. First wing 720 extends about 90 degrees around the perimeter of body portion 702. A gap 724 is provided between first wing 720 and body portion 702 so that a free end 726 of first wing 720 can flex relative to first land 710. Unlike spring blocker assembly 500, spring blocker assembly 700 has no second wing.
A first space 728 is provided between free end 726 of first wing 720 and second land 714. Unlike spring blocker assembly 500, spring blocker assembly 700 has no second space.
When the spring blocker 700 is rotated to a first position, as shown in
Referring now to
As described above with respect to other embodiments, as screw 160 are inserted, screw head 162 engages beveled wings 826, 836, and biases wings 826, 836 inward, toward the center 804 of spring blocker assembly 800. After screws 160 are inserted far enough into the vertebrae such that heads 162 are below wings 826, 836, wings 826, 836 snap back into their unbiased positions to cover a portion of screw head 162, preventing screw head 162 from backing out of the respective vertebra.
While spring blocker assembly 800 is shown without a locking cam, those skilled in the art will recognize that a locking cam can be added to provide additional locking capability.
Referring now to
Spring 904 is a continuous helical spring that naturally takes the form of a circle. When spring 904 is inserted into pockets 920, 922, spring still retains a circular configuration. As screws 160 are screwed into a retaining plate 150, 250, 550, 650, 750 utilizing spring blocker assembly 900, screw heads 162 force spring 904 inwardly, toward a center of spring blocker assembly 900. After screw heads 162 are below the level of spring 904, spring 904 naturally returns to its circular configuration, such that spring 904 extends over screw heads 162, retaining screw heads 162 in place.
Referring to
A stem 970 of blocker assembly 950 extends away from gap 956 and incudes a screw 972 that is used to secure blocker assembly 950 to a plate, such as plate 150, 250, 550, 650, 750, or any other type of plate.
Optionally, a cam lock 980 can be located in gap 956 and rotated from an unlocked position, as shown in
In an exemplary embodiment, and of the components described above can be constructed from nitinol, titanium, a titanium alloy, stainless steel, or other suitable biocompatible material.
It will be further understood that various changes in the details, materials, and arrangements of the parts which have been described and illustrated in order to explain the nature of this invention may be made by those skilled in the art without departing from the scope of the invention as expressed in the following claims.
Filing Document | Filing Date | Country | Kind |
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PCT/US20/42227 | 7/16/2020 | WO |
Number | Date | Country | |
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62885863 | Aug 2019 | US | |
62876593 | Jul 2019 | US |