Improvements in and relating to orthapaedic surgical plate implants

Abstract

A symphysis plate is provided for correcting or preventing separation of the anterior pelvic ring. In use, the plate is positioned superiorly over the pubic symphysis and anterior pelvis. It includes a pubis section that is curved in top view to match the natural contour of the anterior pelvic bones, either before separation or after repositioning. The plate also features one or more terminal sections extending from the pubis section, each ending in a terminal fixation point oriented toward the supra-acetabular bone. Multiple connection points are incorporated to receive fixing elements that secure the plate to both the pubis and terminal sections. The terminal fixation points are specifically configured to guide fixing elements along a trajectory that is substantially parallel or co-axial with the horizontal plane of the pubis section and the undersurface of the terminal sections.

Description

[0001] IMPROVEMENTS IN AND RELATING TO ORTHAPAEDIC SURGICAL PLATE IMPLANTS

[0002] STATEMENT OF CORRESPONDING APPLICATIONS

[0003] This application is based on Australian Patent Application Numbers 2024219471 and 2025200061, the entire contents of which are incorporated herein by reference.

[0004] TECHNICAL FIELD

[0005] This invention relates to improvements in and relating to orthopaedic surgical plate implants. For example, the present invention relates to surgical plate implants which are for securing the bones of the anterior pelvis and pubis symphysis. In particular, the present invention provides an anterior pelvic plate with novel terminal fixation point(s) allowing for less invasive fixation within the sciatic buttress.

[0006] BACKGROUND

[0007] The present invention concerns the treatment of pubic symphysis separation or bony injury involving the pubis, which involves a specialised surgical procedure where the anterior pelvic bones are first physically manipulated into place and then, utilising plates fixated to the pelvis, held in place such as illustrated in Figure 1. Plate 10 is fixated by screws 20 into the anterior pelvic bones of the pelvis 30. The strength or stability of the repair is augmented with increasing number of screws, increasing plate length, increasing length of screws and increasing bone quality in which the screw is inserted.

[0008] There are shortcomings with the current plates used to treat, or prevent, this condition.

[0009] As mentioned, the traditional pubic symphysis plate 10 shown in Figure 1 does not attach to the strong bone in the supra-acetabular region of the pelvis (Figure 1 dashed circles C). Whilst pelvic reconstruction plates have been developed as shown by arrow X in Figure 2 to attach to the supra-acetabular region as shown by dashed circles C in Figure 1, their implantation requires additional surgical dissection in the area shown by the shaded regions shown respectively by the dashed circles in DI and D2 in Figures 3A or 3B so a surgeon can apply the plate to the bone and access the required screw holes. These currently available plates also lack reinforcement around the pubic symphysis area and are prone to failure where they overlay the pubic symphysis.

[0010] Extension of plate and screw fixation into the supra-acetabular bone is sometimes desired when the pattern of pubic symphysis instability or anterior pubic bone fracture require additional mechanical stability so as to provide bony stability to allow healing. Factors such as (but not limited to) bone quality, injury severity and patient habitus are taken into consideration by the surgeon when deciding on the extent of the fixation. Thus, a plate which can not only be fixated to the strong bone in the supra-acetabular region of the pelvis but which can also be implanted in a less invasive manner to this region would be useful.

[0011] The reference to any prior art in the specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge in any country.

[0012] DEFINITIONS

[0013] The term 'substantially parallel' means parallel or within plus or minus 15 to 25 degrees.

[0014] The term 'substantially conforming to' means a shape or configuration which generally resembles the shape to which it is said to substantially conform. For example, if something substantially conforms to a circle it will have a predominant circular aspect to its profile.

[0015] The term 'plate' as used herein refers to an internal fixation apparatus which is attached to bone with fixing elements, such as screws, to provide strength to the bone(s) to which it is attached. The plate will have a profile which substantially conforms to shape the bones to which is being affixed. It is used synonymously with the term 'implant'. Furthermore, the terms 'pubic symphysis plate' and 'anterior pelvic plate' can be considered synonymous. Unless stated otherwise, these later two terms refer to the invention.

[0016] The term 'terminal section plane' as used herein refers to the plane created via the upper surface and lower surface of the plate in the terminal sections of the plate, see axis y-y and axis z-z in Figure 5. If viewed from the front or rear, the terminal section plane may have a longitudinal axis coplanar with the 'common planar axis' x-x, such as shown in Figure 5.

[0017] The term supra-acetabular as used herein refers to the part of the pelvis bone which is situated above the cup-like socket (acetabulum) for the head of the thigh bone (femur). It can also be understood by those familiar with the art to be synonymous with the term 'sciatic buttress' which denotes the column of bone between the sacroiliac joint and the hip joint.

[0018] The term 'fixing element' as used herein refers to an elongate member adapted to be fixated to bone which generally secures the plate to the underlying bone. It would most commonly comprise of a locking or nonlocking screw. Locking screws are used widely in prior art, they feature a threaded head which attaches to a screw hole so as to enhance angular stability. Non-locking screws are comprised of a standard screw head.

[0019] The terms 'horizontal plane' and 'common plane' as used herein can be used interchangeably and refer to an axis which extends through both a midline of the pubis section and the terminal section(s) when the plate is viewed, from either the: front, back or side thereof. The 'common plane / horizontal plane' is represented by dashed lines x-x in Figures 5 and 8. The term proximal means "closer or closest to the pubis section" and the term distal means "further or furthest from the pubis section".

[0020] DISCLOSURE OF INVENTION

[0021] According to a first aspect of the present invention there is provided symphysis plate to correct or prevent a separation event involving the anterior pelvic ring wherein in-use the plate is placed over the pubic symphysis (area where the two pubic bones join anteriorly) wherein said plate includes: a pubis section curved, when viewed in top plan, to follow the curvature of the anterior pelvic bones that form the symphysis pubis, prior to separation of the bones, or once the bones are repositioned to the correct position; and at least one terminal section on one side, or on both sides, of the pubis section; which ends in at least one terminal fixation point which orients the terminal fixing element towards the supra-acetabular bone; wherein the plate further includes a plurality of connection points for receiving fixing elements which attach the plate to the pelvis; and wherein the terminal fixation point(s) on at least one terminal section are configured to provide a trajectory via the aperture axis of the terminal fixation point for at least one end fixing element which is / are: substantially parallel or substantially co-axial with a horizontal plane of the pubis section and the undersurface (s of the terminal section(s) associated with an end tapered projection.

[0022] A symphysis plate substantially as described above wherein the tapered projection is elevated from the upper surface of the terminal section and is downwardly tapered toward the distal end of the plate and conforms to the shape of a spherically blunted tangent ogive nose cone cut along the longitudinal axis thereof.

[0023] Optionally there may be more than one terminal connection point at the distal end of the terminal section. For example, the plate may have: two terminal tapered connection points; or two spaced apart apertures within a terminal tapered projection; to allow for insertion of two fixing elements within the sciatic buttress (not shown in figures). Optionally there may also be additional connection points on a terminal section which have a trajectory orthogonal to the plane of the terminal section(s) in which the fixing element(s) will be located.

[0024] In some embodiments the plane of the respective pubis section and terminal section undersurfaces are not co-planar or parallel to one another. The plate in-use may be bent by surgeons such as to enhance its conformity to the underlying bone.

[0025] According to a second aspect of the present invention there is provided a method of treating pubic symphysis separation or anterior pelvic fracture via a surgical procedure comprising the steps of: a) implanting a pubis symphysis plate through a single incision on the repositioned (or reduced) anterior pelvic bones, wherein the plate includes a plurality of connection points and at least one terminal section on one side of a pubis section of the plate; b) fixating the pubis section of the plate to the anterior pelvic bones where necessary with fixing elements which have trajectory which is substantially orthogonal to the plane of the pubis section; c) fixating the terminal section(s) of the plate to the supra-acetabular region of the pelvis via fixing elements which have a trajectory which is substantially parallel or co-axial with a horizontal plane of the pubis section and the undersurface of the terminal section(s) of the plate. d) closing the incision.

[0026] The above-described surgical procedure represents a less invasive option for fixation of the anterior pelvic ring with extension to the supra-acetabular bone than currently available anterior pelvic plates which do not feature our novel terminal tapered projection and aperture therein.

[0027] According to a third aspect of the present invention there is provided a symphysis plate which includes at least two sections: a pubis section; and at least one terminal section extending from one or both sides of the pubis section; wherein fixing elements used in the pubis section pass through apertures therein configured to provide a trajectory for a fixing element which is substantially orthogonal to the undersurface of said section; and wherein fixing elements used on the terminal section pass through apertures therein configured to have a trajectory angled with respect to the fixing elements of the pubis section; the symphysis plate is characterised in that at the terminal end(s) of the terminal section(s) there is provided at least one terminal fixing element passing through an aperture with a hole axis providing a trajectory for the terminal fixing element(s) which is / are substantially parallel or co-axial with a horizontal plane axis of the plate.

[0028] According to a fourth aspect of the present invention there is provided a symphysis plate which includes at least two sections: a) a pubis section; and b) at least one terminal section extending from one or both sides of the pubis section; wherein the distal end(s) of the terminal section(s) each have a tapered projection which projects up from the top surface of the terminal section, which includes an aperture therein enabling a terminal fixing element to pass through the tapered projection, wherein the tapered projection further includes: a curved apex when viewed from above as a front edge and wherein said tapered projection includes an aperture which has an aperture axis, which is substantially parallel or co-axial with a horizontal plane of the plate and / or the underside of the terminal section associated with the tapered projection.

[0029] According to a fifth aspect of the present invention there is provided a symphysis plate wherein the terminal tapered projection (fixation point) forms the distal end of the plate and wherein the projection is elevated from the upper surface of the terminal section and is downwardly tapered toward the distal end of the plate.

[0030] According to a sixth aspect of the present invention there is provided a symphysis plate which includes: a) a pubis section which has an arcuate profile and two opposed ends with apertures therein for receiving fixing elements; b) at least one terminal section which extend(s) from one, or respectively extend from different opposed ends of the pubis section with apertures therein for receiving non-terminal fixing elements; wherein at the distal end of the terminal section(s) there is provided at least one tapered projection which is elevated from the upper surface of the remaining terminal section and which includes a substantially horizontal aperture therein for receiving at least one terminal fixing element therein ; wherein the pubis section and the terminal section share a common plane; and wherein the fixing elements in the pubis section have a longitudinal axis orthogonal to the undersurface of the pubis section of the plate; and wherein the non-terminal fixing elements in the terminal section have a longitudinal axis which is orthogonal to the undersurface of the terminal section of the plate; wherein the distal fixing elements in the terminal section have a longitudinal axis which is substantially parallel or substantially co-axial with a common horizontal plane of the pubis section and the undersurface(s) of the terminal section(s) associated with the end or distal tapered projection.

[0031] In preferred embodiments the non-terminal fixing elements in the terminal section may be acutely angled with respect to the fixing elements in the pubic section.

[0032] It should be understood that the substantially horizontal aperture in the tapered projection is substantially aligned or parallel to the longitudinal plane of the pubis section.

[0033] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to".

[0034] Where in the foregoing description, reference has been made to specific components or integers of the invention having known equivalents, then such equivalents are herein incorporated as if individually set forth.

[0035] The invention may also be said broadly to consist of a prior art pubic symphysis plate that is enhanced by at least one terminal section which features a novel terminal screw hole which allows the fixation to be extended to the robust bone of the sciatic buttress.

[0036] Further aspects of the invention, which should be considered in all its novel aspects, will become apparent from the following illustrations and description given by way of example of possible embodiments of the invention.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The invention is now discussed with reference to the Figures which are given by way of example only.

[0039] Figure 1 shows a currently available prior art pubic symphysis plate representative of the current state of the art. The dashed circles represent the supra-acetabular bone which is generally relatively robust and is located in the area of the pelvis between the hip and sacroiliac joints.

[0040] Figure 2 shows a currently available prior art pelvic reconstruction plate showing an extension of the plate for supra-acetabular fixation to the pelvis.

[0041] Figures 3A & 3B show a currently available prior art pelvic reconstruction plate showing an extension of the plate for supra-acetabular fixation to the pelvis indicating the shaded area (demarcated by the dashed lines) where extra dissection is required (in comparison to the dissection required for supra-acetabular fixation using the novel implant described herein). The figures focus on the left hemipelvis (which is to the right of the figure). The main embodiment of the novel implant described herein is shown as faded. Figure 3a shows the additional dissection (shaded area - located within the dashed lines) required for traditional plate fixation to the supra-acetabular bone when fixation is inserted through the anterior intrapelvic (also known as 'Stoppa') surgical approach while figure 3b shows the same for fixation using the lateral window of the ilioinguinal surgical approach.

[0042] Figure 4 shows a perspective view in accordance with the preferred embodiment of the present invention.

[0043] Figure 5 shows a rear elevation in accordance with the preferred embodiment of the present invention.

[0044] Figure 6 shows a top plan view of in accordance with one preferred embodiment of the present invention.

[0045] Figure 7 shows perspective view of a pelvis and the present invention according to the main embodiment in an in-use position, and in particular shows the inner surface of the acetabulum 80 (which is the socket for the hip joint).

[0046] Figure 8 shows a terminal end view of an embodiment of the present invention where there is only one terminal section visible and illustrates the common planar axis.

[0047] Figures 9A shows a front-oblique profile of the distal end of the tapered terminal fixation point, also shown in the above Figures.

[0048] Figure 9B shows a cross-sectional side profile of the tapered terminal fixation point. It illustrates how the elevated profile of the terminal fixation point allows for a screw axis which is substantially parallel to the undersurface and top surface of the flat portion of the terminal section. It should be noted that pelvic anatomy would allow for the terminal screws to be much longer than those illustrated, thus providing robust fixation of the implant to the bone.

[0049] Figure 9C shows a front-oblique profile of the distal end of the tapered terminal fixation point with the exit point of terminal aperture.

[0050] Figure 9D shows a top plan profile looking down on the tapered terminal fixation point.

[0051] Figure 10 shows an undersurface view of the preferred embodiment of the implant.

[0052] DISCUSSION OF FIGURES INCLUDING BEST MODES FOR CARRYING OUT THE INVENTION

[0053] As shown in Figures 4-10 there is shown a pubic symphysis / anterior pelvic plate 1 (henceforth referred to as 'the plate', 'the invention' or 'the implant') according to one preferred embodiment of the present invention which is made from surgical grade stainless steel, titanium or other surgically acceptable materials as would be known to one skilled in the art.

[0054] Alternatively, the implant can be manufactured following standard methods for fabrication of orthopaedic implants including 3D printing-based production.

[0055] Use of an implant in surgery requires sterilisation and handling as per industry accepted methods.

[0056] Figure 4 illustrates how the plate has a pubis section shown by arrow 2 which is curved (when viewed from above - see also Figure 6) to follow the curvature of the anterior pelvic bones that form the symphysis pubis, prior to separation, or once repositioned to correct the separation. As variance in the curvature of the anterior pelvis is known to occur, the implant may be manufactured and provided in varying radii or alternatively, the implant may be customised to fit the anatomy of the patient for which it is destined.

[0057] The plate has a plurality of connection points in the form of spaced apart apertures 5 in the pubis section 2 (Figures 4 and 6) which can receive fixing elements, more commonly in the form of screws (Figure 7). These apertures 5 have a hole axis 6 (Figure 4) which is orthogonal or substantially orthogonal (i.e. within + / - 20 degrees) to the undersurface 7 of the pubis section (Figure 8). These types of apertures, which are spread across what is otherwise a reasonably flat plate, are commonly found in bone plates used in orthopaedic surgery.

[0058] As can be seen in the main embodiment in Figure 4, the pubis section 2 has more material surrounding the apertures 5 providing greater structural integrity / strength relative to the terminal portions. This greater strength of the pubis section relative to the terminal portions allows greater structural integrity to resist failure of the implant around the pubic symphysis. The design is however such that a surgeon still has the ability to twist or bend any section of the plate as required to fit an individual's pelvis if required. For example, if made from stainless steel the plate may have a thickness of around 3-5mm.

[0059] In other embodiments, the implant may be produced with varying degrees of reinforcement not only in the pubic section but also in the terminal section(s). The plate has on either side of the pubis section 2 left and right terminal sections 3,4 (Figures 4 - 10). These are joined to the pubis section 2 by segment 17 which has a tapered thickness, and which may also be reinforced or curved to: contour to the anterior pelvic brim; provide a desirable trajectory for screw or fixing element insertion in the terminal and on- terminal apertures of the terminal section.

[0060] In the currently preferred embodiment shown in the figures made of stainless steel the segment 17 tapers down from a thickness of 4.5mm for the pubic section interface to 3.2mm for the terminal section interface.

[0061] A desirable trajectory for a fixing element being hole axis w-w of terminal aperture 9 shown in Figure 9B and is important for the novel design as it allows the surgeon relatively easy access to the terminal aperture 9 for fixing element insertion. The hole axis w-w also allows for orienting the terminal fixing element (most commonly a screw) outside of the hip joint; and keeps the elevated terminal fixation point low in the pelvis and away from the hip flexor muscles and tendons which course over the anterior aspect of the hip joint (not shown in the Figures).

[0062] The longitudinal plane of pubis section 2 shown by dashed line X-X (Figures 5 and 8) is substantially horizontal when viewed from a front or rear elevation relative to the planes of the terminal sections 3,4 shown by respective dashed lines Y-Y have an angle of 0yand Z-Z have an angle of 0Zwhich are inclined with respect to the horizontal as shown in Figure 5. Angles 0yand 0zare of approximately 45 degrees but may vary depending on the embodiment and may also be adjusted by the surgeon by applying twisting the plate.

[0063] The plate has a plurality of connection points in the form of apertures 8 in the respective terminal sections 3,4 which can receive non-terminal fixing elements in the form of screws (Figures 4, 6, 7, 8 and 9).

[0064] The hole axis of the apertures 8 on the respective lefthand and righthand side terminal sections 3 ,4 are orthogonal to the planes of each of the terminal sections 3,4.

[0065] The terminal sections 3,4 each also include at least one terminal connection point 15 which contains aperture 9 (figures 9A, 9B & 9C). It is the configuration of this terminal connection point which renders this implant novel in the field of orthopaedic surgery. The terminal aperture 9 on each terminal section 3,4 has a hole axis w-w (see Figure 7 and terminal fixing element 75) which is substantially parallel (i.e. within + / - 20 degrees) to: the undersurface 7 of the pubis section; and / or the undersurface 11 of the terminal section in which the terminal aperture is located; and / or the common planar axis x-xofthe pubis section and the undersurface(s) of the terminal section(s) associated with the an end tapered projection, (horizontal plane) .

[0066] The hole axis w-w of terminal aperture 9 as can be seen from the trajectory of terminal fixing elements 75 shown in Figures 8 and 9B, the latter which illustrates a cross section of terminal fixation point 15 on the true left side of the implant. Aperture 9 and axis w-w are seen to be substantially parallel to the undersurface 11 of terminal section 3.

[0067] The terminal sections 3,4 each have a recess 12 in the top surface 13 thereof adjacent the terminal aperture 9 to facilitate partial passage of the head of the fixing elements 75 (figures 4 and 6).

[0068] The distal ends 14 of the terminal sections 3,4 each have a tapered superior projection 15 with a curved apex 16 (Figure 4).

[0069] As can be seen in Figures 4 and 9B illustrating the implant 1 it can be seen the tapered projection 15 projects above the top surface 13 of the terminal section 3 and has a side profile which is sloped down from the top 90 of the proximal end to the distal end 91.

[0070] Figures 4 and 9A shows the tapered projection 15 has a semicircular rear profile (perhaps seen best on Figure 4 right hand side) with aperture 9 fitting within this volume. As previously mentioned, the tapered projection 15 is also raised from the top surface 13 of the respective terminal sections 3 and or 4.

[0071] As can be seen in Figure 4 the tapered projection 15 (on the right-hand side) has an external contour which conforms to the shape of a spherically blunted tangent ogive nose cone, that has been cut along the longitudinal axis thereof.

[0072] This novel configuration of the tapered projection to create an aperture for the terminal fixing element differs from currently available implants. The latter do not feature fixation points such as terminal fixation point 15 which maintains bony contact with the underlying bone (Figure 7) yet allows for insertion of fixing elements in an orientation substantially parallel to: the common planar axis of the implant, the flat longitudinal surfaces of the implant as described above, the entry point of the underlying bone into which they are being inserted.

[0073] Figure 9C shows the front and undersurface profile of the tapered projection 15 which narrows from the proximal to the distal end of the terminal fixation point. It also shows, along with Figure 10 the oblong or oval shaped exit point of aperture 9 on the undersurface of the implant.

[0074] Figure 9D is a top plan of the tapered projection and shows how the distal end 91 is curved. It also shows, along with Figure 7, that the axis (w-w) of the terminal fixation point aligns substantially with the pubis section 2 of the implant. This allows the surgeon a direct line of sight from the anterior incision to ensure the implant is well positioned on bone and for easy screw insertion, without applying excessive retraction to the surrounding tissues.

[0075] The aforementioned figures illustrate the three-dimensional volume which makes up the terminal fixation point. Figure 7 illustrates how such a configuration allows for a fixation device such as a screw to be oriented outside of the hip joint into the supra-acetabular bone. A traditional aperture (for example 5 or 8) in this location does not allow such a screw trajectory unless a significant bend is applied to the plate between the pre-terminal and terminal apertures. This is undesirable as the act of bending a plate weakens it thus rendering it prone to breakage. This practice would also leave the soft tissues surrounding the terminal aperture vulnerable to injury from drill or fixing element passage between the undersurface of the aperture and the entry point in the bone.

[0076] Figure 9B illustrates the relatively (in comparison to standard screw holes such as aperture 8) long trajectory taken by the fixing element through aperture 9. Figure 7 illustrates how the fixing element is held within the semi-tubular terminal fixation point 15 from its entry into aperture 9 to its entry into the underlying bone, thus protecting the surrounding soft tissues from injury during insertion of the fixing element.

[0077] The apertures 5 in the pubis section 2 and apertures 8 in the terminal section 3, 4 have been countersunk on the top surface 13 of the implant as is commonly seen in prior art. The undersurface as is seen in Figure 10 may be flat or undulating such as to limit contact with bone as commonly seen in prior art.

[0078] Combining the features described above, the invention is shown in-use in Figure 7 fixated to the left and right pubic bones 73,74 of the pelvis 70 using screws 71. The implant is also fixated to the left and right iliac bones or sciatic buttress portion of the pelvis via fixing elements 75 which are oriented away from the acetabulum (hip socket) thanks to the novel design of terminal fixation point in the form of tapered projection 15.

[0079] As can be seen the pubis section 2 has pubis fixing elements in the form of non-locking or locking screws 71 which are located in apertures 5 which have a hole axis which is orthogonal or substantially orthogonal (i.e. within + / - 20 degrees) to the undersurface 7 of the pubis section. The apertures 5 represent holes in a flat plate with the variation in fixing element axis or longitudinal screw axis, LSA, coming from the difference in size of the aperture and the relatively smaller screw threads, as is commonly seen in prior art. The implant also has terminal sections 3,4 (Figure 6) with apertures 8 with non-terminal fixing elements in the form of locking or non-locking screws 72 (of which one is shown on each side in Figure 7) and which have a longitudinal axis which is substantially orthogonal to the undersurface 11 of the respective terminal sections 3,4.

[0080] The terminals sections 3,4 contain the novel a terminal aperture 9 in tapered projection 15 in which the terminal fixing screw 75 has a longitudinal axis which is substantially parallel to the undersurface 11 of the terminal sections 3,4 as well as the common planar axis / horizontal plane x-x. The terminal fixing screws 75 pass through the semi-cylindrical apertures 9 in the terminal sections 3,4 (Figures 3a 3b, 7, 8, 9).

[0081] ALTERNATIVE WAYS FOR IMPLEMENTING THE INVENTION

[0082] The plate is typically made from surgical grade stainless steel or titanium. However, the plate may be made from other biocompatible materials as would be known to one skilled in the art without departing from the scope of the present invention.

[0083] The connection points may come in a variety of different forms without departing from the scope of the present invention.

[0084] The connection points may include a tapered entry to the aperture to enable a fixing element to be countersunk to provide a flush outer top surface of the connection point.

[0085] In a still further example one or more of the terminal connection points may include at least one recess in the top surface of the plate to facilitate partial passage of the head of a fixing element. Furthermore, the proximal aspect of aperture may contain a recess so as to allow a screw head to fit in a countersunk manner

[0086] The fixing elements may come in a variety of different forms without departing from the scope of the present invention, all being made from a surgically acceptable material.

[0087] In one example, the fixing elements may be locking or non-locking screws. In another example, the fixing elements may be in the form of a suture anchor or cable.

[0088] The invention may also be said to include the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

[0089] It should be noted that various changes and modifications to the presently preferred embodiments or examples described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. Although this invention has been described by way of example and with reference to possible embodiments thereof, it is to be understood that modifications or improvements may be made thereto without departing from the spirit or scope of the appended claims. For example, the implant may be manufactured in various sizes with various numbers of apertures in its pubis and terminal sections.

Claims

WHAT WE CLAIM IS:

1. A symphysis plate to correct or prevent a separation event involving the anterior pelvic ring wherein in- use the plate is placed superiorly over the pubic symphysis (area where the two pubic bones join anteriorly) and anterior pelvis wherein said plate includes: a. a pubis section curved, when viewed in top plan, to follow the curvature of the anterior pelvic bones that form the symphysis pubis, prior to separation of the bones, or once the bones are repositioned to the correct position; and b. at least one terminal section on one side, or on both sides, of the pubis section; which ends in at least one terminal fixation point which orients the terminal fixing element towards the supra-acetabular bone; wherein the plate further includes a plurality of connection points for receiving fixing elements which attach the plate to the pelvis at both the pubis section and the terminal section; and wherein the end terminal fixation point(s) on at least one terminal section are configured to provide a trajectory via the aperture axis for at least one end fixing element which is: i. substantially parallel or substantially co-axial with a horizontal plane of the pubis section and the undersurface(s) of the terminal section(s) associated with an end tapered projection.2- A symphysis plate as claimed in claim 1 wherein the tapered projection is elevated from the upper surface of the terminal section and is downwardly tapered toward the distal end of the plate and conforms to the shape of a spherically blunted tangent ogive nose cone cut along the longitudinal axis thereof.

3. A symphysis plate which includes at least two sections: a. a pubis section; and b. at least one terminal section extending from one or both sides of the pubis section; wherein fixing elements used in the pubis section pass through apertures therein configured to provide a trajectory for a fixing element which is substantially orthogonal to the undersurface of said section; and wherein proximal fixing elements used on the terminal section pass through apertures therein configured to have a trajectory substantially orthogonal to the undersurface of said section;the symphysis plate is characterised in that at the distal end(s) of the terminal section(s) there is provided at least one terminal fixing element passing through an aperture with a hole axis providing a trajectory for the terminal fixing element(s) which is / are substantially parallel or substantially co-axial with a horizontal plane of the pubis section.

4. A symphysis plate which includes at least two sections: a. a pubis section; and b. at least one terminal section extending from one or both ends of the pubis section; wherein the distal end(s) of the terminal section(s) each have a tapered projection which projects up from the top surface of the terminal section, which includes an aperture therein enabling a terminal fixing element to pass through the tapered projection, wherein the tapered projection further includes: a curved apex when viewed from above as a front edge and wherein said tapered projection includes an aperture which has an aperture axis, which is substantially parallel or substantially co-axial with a horizontal plane of the pubis section and / or the underside of the terminal section associated with the tapered projection.

5. A symphysis plate as claimed in claim 4 wherein the end or distal tapered projection (fixation point) is elevated from the upper surface of the terminal section and is downwardly tapered toward the distal end of the plate.

6. A symphysis plate which includes: a. a pubis section which has an arcuate profile and two opposed ends with apertures therein for receiving fixing elements; b. at least one terminal section which extend(s) from one, or respectively extend from different opposed ends of the pubis section with apertures therein for receiving non-terminal fixing elements; wherein at the distal end of the terminal section(s) there is provided at least one tapered projection which is elevated from the upper surface of the remaining terminal section and which includes a substantially horizontal aperture therein for receiving at least one terminal fixing element therein; wherein the pubis section and the terminal section share a common plane ; andwherein the fixing elements in the pubis section have a longitudinal axis orthogonal to the undersurface of the pubis section of the plate; and wherein any non-terminal fixing elements in the terminal section have a longitudinal axis which is orthogonal to the undersurface of the terminal section of the plate; and wherein the distal fixing elements in the terminal section have a longitudinal axis which is substantially parallel or substantially co-axial with a common horizontal plane of the pubis section and the undersurface(s) of the terminal section(s) associated with the end or distal tapered projection.

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