DESC:DESCRIPTION
FIELD OF INVENTION
The present invention relates to the fixation of patella fractures. In particular, the present invention discloses a rigid implant particularly without involving the joint surface and without occupying much space anteriorly so that the patient’s patella is conserved and the plate need not be removed.
BACKGROUND OF THE INVENTION
Nowadays patella fractures are common. Patella is basically knee cap bone. Accurate reduction and fixation of a fracture is essential to mobilize a knee joint early. However, available implants do not satisfy all the requisites of such treatment. For example, tension band technique is effective only when there are two major fragments of bone, which may not be the case all the time. In managing patients, who have fracture in multiple small pieces, the implants available are very less. Simple cerclage wires that are just go around the fractured bone pieces will not offer much rigidity to allow any movement of the knee joint.
Currently, there are plates available with hook type systems which go into an articular surface to hold the patella like a clip. In this method, there is invasion of the joint, which may irritate the joint and will necessitate removal of the implant. There are other plate systems which are star shaped covering the entire anterior surface of the patella. This will separate the subcutaneous tissue for falling back to the bone after the surgery.
At present, there are no such implants which will comfortably hold the fragment without entering and invading the intra articular side, i.e., inside surface of the patella, or on the outside, i.e., invading almost entire anterior surface.
SUMMARY OF THE INVENTION
The present invention is directed towards the fabrication of a specially designed locking plate for fixation of the one or more fractures in a patella bone.
In one embodiment ofthe present invention, the locking plate includes an O-shaped base plate for patella facture is disclosed, which is a novel plate for treating patella fractures broken into several pieces without involving the joint surface or occupying much space in front of patella. Accordingly, the base plate adapted to be attached to an anterior surface of the patella. The base plate defines a plurality of holes. The base plate is O-shaped.
Further, the plurality of holes are pointing towards an axis of the base plate.
Further, the plurality of holes are equidistant from each other.
Further, the plurality of holes allows visualization of the one or more fractures in the patella.
Further, each of the plurality of holes is defined at a prefixed angle and is directed towards the centre of the base plate.
Further, each of the plurality of holes is adapted to receive a locking screw to securely attach the base plate with the patella.
Further, the base plate does not require a hooking device to attach the base plate to interior of the patella.
Further, the base plate is a rigid implant.
Further, a diameter and a size of the base plate are in accordance with the patella.
Further, a thickness of the base plate is about 3 millimetres.
The advantages of the present invention include, but not limited to, providing rigid implant having an O-shape that occupies less space on the patella in comparision to existing solutions. Due to O-shape in front and plurality of holes on the base plate, the locking plate allows visualization of fracture fixation during every step.
Further, the base plate does not require a hooking device to attach the base plate to interior of the patella. Therefore, locking plate fixes the patella fracture in a less invasive manner as compared to existing solutions.
Further, the locking plate is simple in construction due to O-shaped plate with plurlaity of holes. In addition, the locking plate does not includes lot of aligment plates or other peripheral devices. Therefore, manufacturing costs are largely reduce resulting in cheap large scale production.
Further, due to the holes being defined at a prefixed angle and directed towards the centre of the base plate, the locking screws give a good rigid fixation.
BRIEF DESCRIPTION OF FIGURES
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying figures, representing various embodiment of the invention, in which like reference numerals represent like parts throughout the drawings, wherein:
Figure1 illustrates a top view of a locking plate with an O-shaped base plate for patella, in accordance with an embodiment of the present invention.
Figure 2 illustrates a side view of the locking plate with an O-shaped base plate for patella, in accordance with an embodiment of the present invention.
Figure 3 illustrates a locking screw, in accordance with an embodiment of the present invention.
Figure 4 illustrates a side view of the plate with locking screw in situ to show the angle of the screws when applied into the plate and fully screwed, in accordance with an embodiment of the present invention.
Figure 5 illustrates an exemplary transverse section of a fractured patella bone to show multiple pieces of bone, in accordance with an embodiment of the present invention.
Figure 6 illustrates provisional fixation of patella fracture done with K- wires before applying the locking plate, in accordance with an embodiment of the present invention.
Figure 7 illustrates the locking plate being placed over the fractured patella after provisional fixation, in accordance with an embodiment of the present invention.
Figure 8 illustrates a sleeve for a drill bit for drilling holes for locking screws, in accordance with an embodiment of the present invention.
Figure 9 illustrates a hole is being drilled with a drill bit using a sleeve attached to the screw hole, in accordance with an embodiment of the present invention.
Figure 10 illustrates the depth of the hole that was drilled earlier being measured using a depth gauge, in accordance with an embodiment of the present invention.
Figure 11 illustrates suitable length screws being tightened with a hexagonal screw driver, in accordance with an embodiment of the present invention.
Figure 12 illustrates one screw in place of the locking plate, in accordance with an embodiment of the present invention.
Figure 13 illustrates the locking plate for patella after fixation of all the screws, in accordance with an embodiment of the present invention.
Figure 14 illustrates locking plate for patella after fixation of all the screws and after removal of the K- wires, in accordance with an embodiment of the present invention.
Further, skilled artisans will appreciate that elements in the figures are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the figures with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
DETAILED DESCRIPTION
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the figures 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, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.
Reference throughout this specification to “an aspect”, “another aspect” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase “in an embodiment”, “in another embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by "comprises... a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.
Embodiments of the present invention will be described below in detail with reference to the accompanying Figures.
Patella is a bone which covers the anterior aspect of the knee joint. Any fracture of this bone results in an intra-articular fracture. Even minor changes in the alignment can cause severe irreversible damage to cartilage of the inside of the patella. This causes painful condition call arthritis later on. Powerful muscles of the thigh act on the various pieces of the fractured patella especially the upper piece.
Most implants do not specifically address all the configurations of fractures. The fracture fixation is decided by eyeballing the fracture site, i.e., both the provisional and definite fixation is done by rough approximation only. There are locking plates designed to occupy the entire anterior surface of patella. These also prevent the intra-operative visualization of the fragments as the fracture is being fixed. This will not allow the soft tissues to fall back to get attached to patella surface. Some implants have a hook like device to hold the patella fragments from the joint side and front side included like a forceps. Also no implant is designed to be less invasive with space in front to see the fracture fragments as they are being fixed. Current implants have either a hook device or occupy the anterior surface of patella fully due to above problems.
As per the present invention, patella fracture is first provisionally reduced and fixed with multiple coronally placed K-wires. After that an O shaped plate is kept on the anterior aspect of the provisionally reduced patella. The locking screws may be of length of 16-18 mm. When the O plate is placed on top of the fractured patella, the configuration of the fracture can be continuously watched as the screws are being applied. One of the advantages of present invention is that a rigid implant can control all fragments around the domain of patella and is still less invasive allowing visualization.
The surgeon can directly see the fractured patella while the patella is being fixed. Angle stable locking screws can be placed in each threaded hole of the appropriate sized O shaped patella plate. This mechanism can hold the bones in very severely injured patellae and softened bone due to disuse in non-unions and/or in old people. Like any other locking plate device, the compression from the plate on the bone is not there. It prevents the periosteal compression, thus preserving the blood supply to the bone. The O shaped patella plate with locking screws can be used in comminuted patella fractures and bones of similar shape. The locking screws provide good rigid fixation even in case of osteoporotic bone. Apart from fresh fractures, these plates can be used in patellar non-unions as retaining the patella in any cost is the trend nowadays. This is because the patella is almost very essential to have a total knee replacement at a later date. The only case to be cautious before applying this plate is an existing local infection in the patella area. Different sizes of the plate can be manufactured. The size of the normal uninjured side patella is measured before the operation can help in deciding the diameter and size of the implant. The thickness of the plate shall be around 3 millimetres (mm) and locking screws of diameter around 2 mm can be used. For the insertion of these screws dedicated drill bits must be used. Once the implant is placed rigidly in situ, the patient can be asked to mobilize the knee without any external support.
With reference to accompanying figures, the entire operation is summarized hereinafter. First of all, an O-shaped device is fabricated as shown inFigure 1 and Figure 2. This is the plate which is placed on the fractured patella. In the surface of the plate perpendicular to the plane of the O, locking holes are made equidistant from each other. These holes are directed towards the centre of the O. Locking screws used are as shown in the Figure3. When the locking screws are applied then they will be angled towards the centre of the O as shown in Figure 4. When the comminuted patella bone, i.e., broken in many pieces is exposed as shown in Figure 5, it is first fixed with small K wires for provisional fixation as shown in Figure 6.After that an appropriate sized O plate is selected and placed on the top of the anterior surface of the patella bone as shown in Figure 7. The size can be determined with the uninjured patella. Specially designed threaded drill sleeves are fixed to the locking holes as shown in Figure 8 and then the holes around the O plate are drilled as shown in Figure 9. The length of the hole is measured with a depth gauge as shown in Figure 10. Locking screws are applied with proper hexagonal screw driver for each hole as shown in Figure 11.For unicortical purchase mode, the drill with stop at 1.6 mm or 1.8mm and appropriate sized screws may be used. The screws are fully tightened as shown in Figure 12. The final position will be in the form of a fixation of the holes all around as shown in Figure 13. After all screws are applied, if the provisional wires are loose enough to be removed with hand, they are removed as shown in Figure 14. One of the advantages of the present invention is that the O shaped plate is rigid and still allows soft tissue to fall back to the anterior surface of the patella. At the same time, it also allows visualization of the facture fixation during every step.
Each of the figures is explained briefly hereafter. Figure 1 illustrates a top view of a locking plate (100) comprising a base plate (101) having an O-shape for patella, in accordance with an embodiment of the present invention. The base plate (101) is adapted to be attached to an anterior surface of the patella. The base plate (101) defines a plurality of locking holes (102). The locking holes (102) (hereinafter interchangeably referred to as holes (101)) with threads are given around the plate to pass locking screws to hold the fragments all around with rigidity. These locking holes (102) all around the plate (101) are directed from the anterior surface towards the centre of the plate (101). In other words, the locking holes (102) are pointing towards an axis of the base plate (101). There are threads available in these holes (102) to allow the screws to pass through plate and enter the fracture fragments in a prefixed angle and pass through for a fixed distance of 16mm to 18mm into the fragments of the broken bone to hold them.
Figure 2 illustrates side view of the locking plate (100) with the O-shaped base plate (101) for patella, in accordance with an embodiment of the present invention. Locking holes (102) are given around the plate to pass locking screws to hold the fragments all around with rigidity. The locking holes (102) are equidistant from each other and allow visualization of the one or more fractures in the patella. The base plate (101) is devised with holes (102) all around the anterior surface of the base plate (101). The holes (102) are in a prefixed angle to allow the screws to pass through base plate (101) in a fixed angle to allow the screw to enter the fracture fragments and pass through for either the drilled hole fully for bicortical purchase or for a fixed distance of 16mm to 18mm for unicortical purchase - into the fragments of the broken bone to hold them. There are threads available in these holes (102) to engage the screws in the head of the screws.
Further, each of the locking holes (102) is adapted to receive a locking screw to securely attach the O-shaped base plate (101) with the patella. Figure 3 illustrates such a locking screw (103), in accordance with an embodiment of the present invention. Apart from the usual screw threads in the body (103-1) of the locking screw (103), this locking screw (103) has threads in the head (103-2) of the screw. These screw threads in the head (103-2) get locked with the threads of the locking hole (102). As such, the base plate (101) does not require a hooking device to attach the base plate to interior of the patella.
Figure 4 illustrates a side view of the base plate (101) with locking screw (103), in accordance with an embodiment of the present invention. The locking screw (105) is in situ in the locking holes (102) at an angle when applied into the base plate (101) and fully screwed. As such, the locking screws (103) are directed towards the centre of the base plate (101). This securely and rigidly attaches the base plate (101) with the patella.
Figure 5 illustrates an exemplary transverse section of a fractured patella bone (104) to show multiple pieces of bone. As can be observed, the bone (104) is broken or fractured at multiple points.
Figure 6 illustrates provisional fixation of patella fracture done with anteroposterior direction wires or K- wires (105) before applying the O-shaped base plate (101), in accordance with an embodiment of the present invention. The anteroposterior direction wire can still be retained there when the base plate (101) is applied on the anterior surface of the bone as the central hole of the base plate (101) will accommodate it. For the sake of brevity, only two K-wires are illustrated.
Figure 7 illustrates O-shaped base plate (101) being placed over the fractured patella (104) after provisional fixation, in accordance with an embodiment of the present invention. The wires (105) are accommodated and are removed, if necessary, later after the fixation of base plate (101) or retained as the case may be. As described earlier, a diameter and a size of the O-shaped base plate (101) is in accordance with the patella. Generally, the diameter and size can be determined with the uninjured patella. Further, the thickness of the base plate (101) shall be around 3 millimetres (mm).
Upon placing the locking plate (100) on the patella (104), holes are drilled into the patella (104) through the locking holes (102) for placing the locking screws (105). This enables the locking screws (105) to securely and rigidly attach the locking plate (100) or the base plate (101) to the patella (104). Accordingly, Figure 8 illustrates a sleeve (106) for a drill bit for drilling holes into the patella (104) for locking screws (103), in accordance with an embodiment of the present invention. These sleeves (106) have threads that go to lock in the threads of the locking hole (102). This allows the correct angle of the hole for the screw (103) that is going to be tightened in the locking hole (102).
Further, Figure 9 illustrates a hole is being drilled in the patella (104) with a drill bit (107) using the sleeve (106) attached to the locking hole (102). The holes are drilled to a depth in accordance with the height and diameter of the locking screw (103).
Further, Figure 10 illustrates the depth of the hole that was drilled earlier being measured using a depth gauge (108) (in bicortical purchase). As described earlier, holes are drilled to a depth in accordance with the height and diameter of the locking screw (103). The drilling and measuring continues until desired depth is obtained.
After drilling the holes of desired depth in the patella (104), the locking screws are inserted through the locking holes (102) of the O-shaped based plate (101) and into the holes of the patella (104). Accordingly, Figure 11 illustrates screws (103) being tightened with a hexagonal screw driver and Figure 12 illustrates one screw (103) in place through the locking hole (102) and into the hole of the patella (104).
The above process of drilling the holes into the patella (104) and then tightening the locking screws (104) through the locking holes (102) of the O-shaped based plate (101) and into the holes of the patella (104) is continued until all the locking screws (103) are tightened. Accordingly, Figure 13 illustrates an O-shaped base plate (101) for patella (104) after fixation of all the screws (103).
Upon fixing the locking screws (103), the K-wires (105) can be removed. Accordingly, Figure 14 illustrates the base plate (101) fixed to the patella (104) through the locking screws (103) without the K-wires (105). The provisional K-wires (105) can be removed with hand after all screws have been tightened and the K-wires (105) are loose enough. Thus, the base plate (101) is a rigid implant that can control all fragments around the domain of patella (104).
This implant provides rigid fixation all around the domain of patella still allowing the surgeon to directly visualize the fracture reduction as it does not cover the entire anterior surface and also not invade the joint surface in the form of hook devices; this will not necessitate the removal of the implant. Further, the base plate does not require a hooking device to attach the base plate to interior of the patella. Therefore, locking plate fixes the patella fracture in a less or no invasive manner.
While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein. The figures and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible.
,CLAIMS:WE CLAIM:
1. A locking plate (100) for fixation of one or more fractures in a patella (104), the locking plate (100) comprising:
- a base plate (101) adapted to be attached to an anterior surface of the patella (104), said base plate (101) defining a plurality of locking holes (102), wherein the base plate (101) is O-shaped.

2. The locking plate (100) as claimed in claim 1, wherein the plurality of locking holes (102) are pointing towards an axis of the base plate (101).

3. The locking plate (100) as claimed in claim 1, wherein the plurality of locking holes (102) are equidistant from each other.

4. The locking plate (100) as claimed in claim 1, wherein the plurality of locking holes (102) allows visualization of the one or more fractures in the patella (104).

5. The locking plate (100) as claimed in claim 1, wherein each of the plurality of holes is defined at a prefixed angle and is directed towards the centre of the base plate (101).

6. The locking plate (100) as claimed in claim 1, wherein each of the plurality of locking holes (102) is adapted to receive a locking screw (103) to securely attach the base plate (101) with the patella (104).

7. The locking plate (100) as claimed in claim 1, wherein the base plate (101) does not require a hooking device to attach the base plate (101) to interior of the patella (104).

8. The locking plate (100) as claimed in claim 1, wherein the base plate (101) is a rigid implant.

9. The locking plate (100) as claimed in claim 1, wherein a diameter and a size of the base plate (101) are in accordance with the patella (104).

10. The locking plate (100) as claimed in claim 1, wherein a thickness of the base plate (101) is about 3 millimetres.