Patent Application
20240358420
The present disclosure relates to an implant permitting different pairs of screws layered in different trajectories for securing a fractured bone to pass therethrough. While discussed largely in connection with use in humeral bone plates, the present disclosure is applicable to other types of medical implants as well.
Fractures to bones are often the result of traumatic injuries. It is well known in the orthopedic arts to reduce and fix a bone fracture with a bone plate. For instance, fractures of the proximal humerus are often treated using bone plates specifically designed for such an application. Especially in older patients, the proximal humerus often has poor bone quality and does not support good screw purchase. Thus, the fixation of the proximal humerus using bone plates is difficult because the head of the humerus tends to collapse over the screws, causing damage to the joint and potential backing out of bone screws placed through the plate.
Current plate and screw designs are not optimal for good screw purchase in the proximal humerus, as well as other similar bones. This often results in less-than-ideal healing for the fractured bone. Thus, it would be desirable for a plate design which permits the placement of screws in a manner that reduces the relative motion of the bone along the screws for higher resistance to pull-out of screws and for higher resistance to bone collapse.
The specific examples herein relate to apparatus and methods for securing a fractured bone with a bone plate to increase screw resistance to pull-out and resistance to bone collapse. For instance, a bone plate in accordance with the present invention has at least four sets of screw holes that permit placement of screws in convergence, standard, convergence, and calcar screw trajectories from the top to the bottom ends of the plate. The orientation of the screw trajectories in the plate reduces the relative motion of the bone along the screws, thereby increasing resistance to pull-out of screws and resistance to bone collapse. The particular hole structures included in the bone plate permit insertion of the screws at various angles, thereby permitting the particular screw orientations discussed herein. This placement may be facilitated through the use of drill guides, screw insertion guides or the like.
In one embodiment, a bone plate for securing a fractured bone comprises a shaft portion and a head portion extending from the shaft portion along a longitudinal axis of the bone plate and including a plurality of holes. The plurality of holes comprises a first pair of screw holes including a first hole and a second hole having central axes that converge towards each other, a second pair of screw holes including a third hole and a fourth hole having central axes that are substantially parallel to each other, a third pair of screw holes including a fifth hole and a sixth hole having central axes that converge towards each other, and a fourth pair of screw holes including a seventh hole and an eighth hole. The seventh and eighth holes have central axes angled towards a most proximal end of the head portion.
In some examples, the first pair of screw holes are positioned between the tip of the head portion and at least one of the second, third, or fourth pairs of screw holes. In some examples, the second pair of screw holes are positioned between the first pair of screw holes and the shaft portion. In some examples, the third pair of screw holes are positioned between the second pair of screw holes and the shaft portion. In some examples, the fourth pair of screw holes are positioned between the third pair of screw holes and the shaft portion.
In some examples, the fourth pair of screw holes are configured to align with a calcar region of bone.
In some examples, the entire head portion is wider than the shaft portion in a direction perpendicular to the longitudinal axis along an upper surface of the plate.
In some examples, the bone plate comprising threads within at least one hole of the plurality of holes, the threads configured to engage a head of a bone screw. In some examples, the threads extend only partially through the at least one hole.
In some examples, the plurality of screw holes further includes a ninth hole disposed between the first and second holes.
In some examples, the plurality of screw holes includes a tenth hole disposed adjacent and forming a triangle with the seventh and eighth holes, and the tenth hole converges toward the seventh and eighth holes beneath a lower surface of the bone plate.
In some examples, at least one of the first, second, third, or fourth pairs of screw holes are disposed on opposite sides of the longitudinal axis of the bone plate.
In some examples, the first and second holes are asymmetrically disposed on the opposite sides of the longitudinal axis.
In some examples, at least one hole of the plurality of holes includes a plurality of spaced apart scalloped regions.
In some examples, the third and fourth central hole axes do not converge beneath a lower surface of the bone plate. In some examples, the seventh and eighth central hole axes do not converge beneath a lower surface of the bone plate.
In yet another embodiment, a bone plate for securing a fractured bone comprises a shaft portion and a head portion extending from the shaft portion along a longitudinal axis of the bone plate and including a plurality of holes. The bone plate is configured to be secured to a humerus head. The plurality of holes are configured to receive screws at differing heights along at least a portion of the humerus head.
In yet another embodiment, a bone plate for securing a fractured bone comprises a shaft portion and a head portion extending from the shaft portion along a longitudinal axis of the bone plate and including a plurality of holes. The plurality of holes includes at least one pair of converging screw holes having central axes that converge towards each other and at least one pair of parallel screw holes having central axes that are substantially parallel to each other. In some examples, the bone plate further comprises an additional pair of screw holes having central axes angled towards a most proximal end of the head portion. In yet another embodiment, a method of securing a bone fracture includes the steps of placing a lower surface of a bone plate against a bone, driving a first screw and a second screw through a proximal end of the bone plate along converging trajectories, driving a third screw and a fourth screw through the bone plate at a location distal of the first and second screws, driving a fifth screw and a sixth screw through the bone plate at a location distal of the third and fourth screws so that the fifth and sixth screws extend along converging trajectories, and driving a seventh and an eighth screw through the bone plate at a location distal of the fifth and sixth screws.
Again, the foregoing method may vary in other embodiments. For instance, the method may include driving the first and second screws, the third and fourth screws, the fifth and sixth screws, or the seventh and eighth screws through their respective screw holes, which may be on opposite sides of the longitudinal axis of the plate. In another embodiment, the method may include driving the third and fourth screws along substantially parallel trajectories. The method may include driving a portion of the seventh and eighth screws into a calcar region of the humerus. The method includes guiding the bone plate along a k-wire to contact the bone.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
A more complete appreciation of the subject matter of the present disclosure and the various advantages thereof may be realized by reference to the following detailed description which refers to the accompanying drawings, in which:
As used herein unless stated otherwise, the term “anterior” means toward the front part of the body, and the term “posterior” means toward the back part of the body. When referring to specific directions in the following description, the terms “proximal” and “distal” are to be understood in regard to the device's orientation and position during exemplary application to human body. Thus, the term “proximal” means closer to the operator or in a direction toward the operator, and the term “distal” means more distant from the operator or in a direction away from the operator. In addition, the terms “about,” “generally,” and “substantially” are intended to mean that deviations from absolute are included within the scope of the term so modified.
Turning now to the figures, a bone plate is shown and will be discussed below. The particular examples shown permit the fixation of a bone plate to the bone using at least four pairs of screws at different orientations. However, the various examples of the bone plate disclosed below are not limited to just the specific designs and uses disclosed herein. For instance, while shown generally as a humeral bone plate, the present invention has applicability for other types of bone plates (e.g., for other long bones, craniomaxillofacial, small fragments, or the like).
As shown in
As previously described, a first imaginary line 28 passes through the first screw 24 and second screw 26; a second imaginary line 42 passes through the third screw 38 and fourth screw 40; a third imaginary line 52 passes through the fifth screw 48 and sixth screw 50; and a fourth imaginary line 62 passes through the seventh screw 58 and eighth screw 60. First imaginary line 28, second imaginary line 42, third imaginary line 52, and fourth imaginary line 62 are sequentially disposed from the proximal to distal end of plate 10. First imaginary line 28 is closest to the proximal end of plate 10, whereas fourth imaginary line 62 is closest to the distal end. The orientation of the screws along the imaginary lines improves bone fixation because the screws are at different height levels along most of the humerus head, therefore preventing the bone from collapsing away or towards the plate.
In accordance with the present invention, the convergence, standard, convergence, and calcar screw trajectories can reduce the relative motion of the bone along the screws. These trajectories therefore can result in a higher resistance to pull-out of screws or to bone collapse. In the prior art, screws are parallel to each other, so the bone is prone to collapsing since the mechanical resistance is in one direction. The orientation of the screws in both converging and diverging trajectories prevents bone collapse because of the mechanical resistance in differing directions. Additionally, the threading of the screws provides further support to the bone to prevent bone collapse.
In the embodiments shown, the screw holes are variable angle holes, which permits screws to be placed at various angles therethrough. For example, the variable angle holes may be holes like those disclosed in U.S. patent application Ser. No. 16/289,826 (now U.S. Pat. No. 11,039,865), the disclosure of which is hereby incorporated by reference herein. Of course, in other embodiments, different variable angle hole designs may be employed. In other embodiments, the screw holes can be single axis holes or can include threading. These non-variable holes would include hole axes aligned to require placement of the screws in accordance with the foregoing discussion. For instance, threaded holes would have fixed angle axes aligned in the manners disclosed above. In alternative embodiments, the screw holes may include additional fixation features, such as scallops, or the like.
Bone plate 10, and any other implant in accordance with the present invention, can be made of any material suitable for implanting into a human body, including but not limited to polymer materials (e.g., PEEK) and metallic materials (e.g., stainless steel or titanium). Plates according to the present invention can be manufactured utilizing any known process, including but not limited to additive manufacturing or the like. It is also contemplated to form certain portions of plate 10 via one process and others via another process. For instance, plate 10 can be 3D printed, with the plate holes thereafter being formed in the plate.
A method of securing a bone fracture using a plate according to the present invention will now be described. The method generally includes placing the lower surface of plate 10 against a bone. This can be done using any means of guiding the plate 10, such as through the use of one or more k-wires. Before the screws are inserted, a threaded hole in the plate may be used for engaging a guide and the bores in the guide may dictate the path of the screws to be inserted. For example, screw hole 36 can be a threaded hole for the guide. Screws may be inserted into slot 17 to allow for plate adjustment before the plate is fixed into place with the remaining screws.
First screw 24 and second screw 26 are then driven through first screw hole 20 and second screw hole 22, respectively, at the proximal end of plate 18 along converging trajectories. Third screw 38 and fourth screw 40 are then driven through third screw hole 34 and fourth screw hole 36, respectively, at a location distal of first screw 24 and second screw 26 along substantially parallel trajectories. Fifth screw 44 and sixth screw 46 are then driven through fifth screw hole 48 and sixth screw hole 50, respectively at a location distal of third screw 38 and fourth screw 40 along converging trajectories. Seventh screw 54 and eighth screw 56 are then driven through seventh screw hole 58 and eighth screw hole 60, respectively, at a location distal of fifth screw 44 and sixth screw 46 in calcar trajectories. Ninth screw 32 and tenth screw 66 are also driven through ninth screw hole 30 and tenth screw hole 64, respectively.
It is to be understood that this method may differ based on surgeon preference, location of the fracture lines, or the needs of the patient. Specifically, the order of insertion may differ for first screw 24, second screw 26, third screw 38, fourth screw 40, fifth screw 44, sixth screw 46, seventh screw 54, eighth screw 56, ninth screw 32, and tenth screw 66 in their respective screw holes.
The foregoing methodology may involve the use of standard tools, such as screw drivers and drills to prepare the bone and place the screws. Guides, such as drill and screw placement guides, can also be utilized. This is particularly true in connection with embodiment plates having variable angle screw holes. The use of guides can dictate the placement of the screws according to the orientations described above. For instance, such guides may force the screws into the convergence, standard, convergence, and calcar screw trajectories noted above. It is also contemplated to utilize a plate according to the present invention along with an intramedullary nail, such that screws pass through both devices.
It is to be understood that the disclosure set forth herein includes any possible combinations of the particular features set forth above, whether specifically disclosed herein or not. For example, where a particular feature is disclosed in the context of a particular aspect, arrangement, configuration, or arrangement, that feature can also be used, to the extent possible, in combination with and/or in the context of other particular aspects, arrangements, configurations, and arrangements of the technology, and in the technology generally.
Furthermore, although the technology herein has been described with reference to particular features, it is to be understood that these features are merely illustrative of the principles and applications of the present technology. It is therefore to be understood that numerous modifications, including changes in the sizes of the various features described herein, may be made to the illustrative arrangements and that other arrangements may be devised without departing from the spirit and scope of the present technology. In this regard, the present technology encompasses numerous additional features in addition to those specific features set forth in the claims below. Moreover, the foregoing disclosure should be taken by way of illustration rather than by way of limitation as the present technology is defined by the claims set forth below.
This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 63/462,290 filed Apr. 27, 2023, the disclosure of which is hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63462290 | Apr 2023 | US |
