Trialling system

Abstract

A trialling system for an orthopaedic implant for knee arthroplasty or partial knee arthroplasty. The trialling system comprises a template (100) for attachment to a tibia in a knee joint. the template (100) comprises: a plate portion (102); and a cutting guide extending through the thickness of the plate portion (102) for guiding a cutting tool for forming a fixation cavity in the tibia. The trialling system comprises a trial component (200). The trial component (200) comprises a body portion (202) which is a distance gauge portion having a thickness of from 2 mm to 10 mm; and an insertion feature extending from a surface of the body portion. The trialling system has an assembled configuration in which the body portion (202) interfaces with the plate portion (102); and the insertion feature extends through the cutting guide and protrudes from the plate portion (102). In use in the assembled configuration with the template (100) being attached to the tibia in the knee joint, the distance gauge portion provides an indication of a distance between the plate portion (102) and a femur of the knee joint.

Description

[0001] TRIALLING SYSTEM

[0002] This invention relates generally, but not exclusively, to a trialling system for an orthopaedic implant for arthroplasty.

[0003] Total or full knee replacement surgery, also known as total or partial knee arthroplasty, is a surgical procedure to resurface a damaged knee joint. During knee arthroplasty the medial and / or lateral side of the tibia of the knee joint are removed and replaced with a tibial implant component.

[0004] There are numerous known designs of tibial implant component for knee arthroplasty. For example some tibial implant components require bone cement to secure the tibial implant component to the tibia, and some are cementless, meaning that they are held in place by an interference fit and / or by one or more fasteners. In most cases, the tibial implant component has a bone insertion feature, for example a keel and / or peg, which extends from a bone-interfacing side of a plate portion of the tibial implant component, and which is configured to be received in a corresponding slot or cavity in the tibia.

[0005] In order to perform knee arthroplasty, a surgeon typically makes a cut down the anterior side of the knee and moves the patella to one side to access the knee joint. The tibia is then resected, and one or more cuts or cavities are formed in the resected tibia for receipt of the one or more bone insertion features. When the surgeon places the bone-insertion features into the tibia, they must align the tibial implant component correctly, and might have to rely upon their cuts and / or cavities to correctly position the tibial implant component. Due to limited access, misalignment can occur, especially as the surgeon has limited visibility of the posterior side of the knee joint. Furthermore, the surgeon may find it difficult to fully bed the bone-interfacing side of the plate portion onto the resected tibia, which is even more difficult on the posterior side which the surgeon might find it difficult to see, especially when an interference fit is used.

[0006] Inaccurate placement may result in poor fixation of the tibial implant component. Poor fixation of the tibial implant component might cause damage to the surrounding bone surface through wear which can cause loosening of the implant. Loosening of the implant may reduce the effectiveness of the implant and may cause the patient problems with mobility and pain. Furthermore, the problems that may arise from inaccurate placement of the tibial implant component can result in further surgical intervention being required, or being required sooner than would be necessary with a correctly positioned implant.

[0007] A template may be used to guide the surgeon as to where to form the slot or cavity in the tibia for correct positioning of the implant. Even so, the slots or cavities may not be formed to the correct depth, which may still result in inaccurate placement of the tibial implant component.

[0008] Moreover, different patients may require tibial implant components of different thicknesses. Currently, sizing of the tibial implant components is done visually by the surgeon. Often the surgeon will have to try a number of tibial implant components before arriving at a tibial implant component that they consider to be of the required thickness. This process is inefficient.

[0009] It would therefore be advantageous to overcome at least some of the aforementioned limitations.

[0010] Aspects of the invention are as set out in the appended claims.

[0011] Advantageously, the trialling system may allow the depth of the fixation cavity to be measured while the template remains in-situ in the knee joint. That is, the template can be used for bone preparation and while the template remains in-situ, the trial component can be coupled to the tibia to allow the dimensions of the formed fixation cavity to be checked. As such, suboptimal preparation of the cavity may be identifiable whilst the template remains in-situ so that a surgeon does not need to reattach the template if they subsequently discover that the fixation cavity is suboptimal. As such, the process of fitting an orthopaedic implant may be made more efficient.

[0012] According to another aspect of the invention there is provided a trialling system for an orthopaedic implant for arthroplasty, the trialling system comprising: a template for attachment to a bone in a joint, the template comprising: a plate portion; and a cutting guide extending through the thickness of the plate portion for guiding a cutting tool for forming a fixation cavity in the bone; and a trial component comprising: a body portion; and an insertion feature extending from a surface of the body portion, wherein the trialling system has an assembled configuration in which: the body portion interfaces with the plate portion; and the insertion feature extends through the cutting guide and protrudes from the plate portion.

[0013] Advantageously, the trialling system allows the depth of the fixation cavity to be measured while the template remains in-situ. That is, the template can be used for bone preparation and while the template remains in-situ, the trial component can be coupled thereto to allow the dimensions of the formed fixation cavity to be checked. As such, suboptimal preparation of the cavity is identifiable whilst the template remains in-situ so that a surgeon does not need to reattach the template if they subsequently discover that the fixation cavity is suboptimal. As such, the process of fitting an orthopaedic implant is made more efficient.

[0014] In certain embodiments, the insertion feature has a pre-determined length which is substantially equal to an intended depth of the fixation cavity in the bone plus the thickness of the plate portion surrounding the cutting guide. That is, the insertion feature is sized so as to protrude from the plate portion by a distance substantially equal to the intended depth of the fixation cavity in the bone.

[0015] In certain embodiments, the insertion feature has a pre-determined profile which is substantially the same as the intended profile of the fixation cavity.

[0016] In certain embodiments, the body portion is a distance gauge portion.

[0017] In certain embodiments, in use in the assembled configuration with the template being attached to a first bone in a joint, the distance gauge portion provides an indication of a distance between the plate portion and a second bone of the joint.

[0018] In certain embodiments, the distance gauge portion has a thickness of from about 2mm to about 10mm, aptly 3mm.

[0019] Advantageously, the trialling system allows both (1) the distance between first and second bones in a joint; and (2) the depth of the fixation cavity to be measured with a single system. That is, the template can be used for bone preparation and while the template remains in- situ, the trial component can be coupled thereto to allow the dimensions of the formed fixation cavity to be checked. The trial component, or more specifically the distance gauge portion of the trial component, also provides a user with an indication of the distance between the first and second bones in the joint so that the user can determine the correct dimensions for an orthopaedic implant. As such, the process of determining the correct dimensions for an orthopaedic implant and also the process of fitting an orthopaedic implant is made more efficient.

[0020] In certain embodiments, the trialling system comprises one or more secondary distance gauge elements configured to interface with the distance gauge portion.

[0021] Advantageously, the secondary distance gauge elements can be used to pack out the distance between the distance gauge portion and a second bone in the joint, where required. As such, where a user finds that the combined thickness of the template and the trial component is visibly less than the required thickness for an orthopaedic implant, the user can use one or more additional secondary distance gauge to increase the thickness of the trialling system so as to approximate the required thickness for the orthopaedic implant.

[0022] In certain embodiments, in the assembled configuration a secondary distance gauge element of the one or more secondary distance gauge elements interfaces with the distance gauge portion.

[0023] In certain embodiments, the one or more secondary distance gauge elements comprises a plurality of secondary distance gauge elements, wherein each secondary distance gauge element of the one or more secondary distance gauge elements is of a different thickness.

[0024] In certain embodiments, an upper surface of the distance gauge portion comprises an engagement feature configured to engage with a corresponding engagement feature on a lower surface of the one or more secondary distance gauge elements.

[0025] Advantageously, providing corresponding engagement, or mating, features in each of the distance gauge portion and the secondary distance gauge elements, allows the secondary distance gauge elements to be substantially locked in place during use. The engagement features also provide haptic feedback to the user that the secondary distance gauge elements is fully seated onto the trial component.

[0026] In certain embodiments, the engagement feature of the one or more secondary distance gauge elements comprises a protrusion, wherein the engagement feature of the distance gauge portion comprises a groove or slot configured to receive the protrusion of the one or more secondary distance gauge elements.

[0027] In certain embodiments, the cutting guide comprises a keel slot guide and the insertion feature comprises a trial keel component.

[0028] In certain embodiments, the trial keel component has a profile which corresponds to the intended profile of the fixation cavity, such that the trial keel component is insertable through the keel slot guide to test the profile of a fixation cavity formed in the bone.

[0029] In certain embodiments, the cutting guide comprises a peg hole guide and the insertion feature comprises a trial peg.

[0030] In certain embodiments, the template comprises two or more cutting guides extending through the thickness of the plate portion and the trial component comprises two or more insertion features, wherein in the assembled configuration each insertion feature of the two or more insertion features extends through a corresponding cutting guide of the two or more cutting guides and protrudes from the plate portion. Advantageously, the trialling system is able to check the depth of any number of fixation cavities while the template remains in- situ.

[0031] In certain embodiments, the cutting guides comprise a keel slot guide and one or more peg hole guide and the insertion features comprises a trial key component and one or more trial pegs.

[0032] In certain embodiments, the trialling system is for an orthopaedic implant for knee arthroplasty or partial knee arthroplasty, wherein the template is for attachment to a tibia. In certain embodiments, the plate portion comprises an attachment hole extending through the thickness of the plate portion, the attachment hole being configured to receive an attachment element.

[0033] In certain embodiments, the body portion comprises an access groove or access hole extending through the thickness of the body portion, wherein in the assembled configuration the attachment hole and the access groove or access hole are aligned.

[0034] Advantageously, by providing the trial component with an access groove or access hole, the user can access the attachment hole while the trial component is in the assembled configuration. As such, both the trial component and the template can be removed from the bone simultaneously.

[0035] In certain embodiments, the plate portion comprises a peripheral edge.

[0036] In certain embodiments, the template comprises a placement element extending from the peripheral edge of the plate portion.

[0037] Advantageously, the placement element allows a user to quickly and accurately place the template on the bone. Furthermore, the placement element helps ensure the template remains in the intended position during attachment of the template to the bone. Furthermore the placement element ensures the template is not overhanging at the rear of the knee joint, where there is minimal visibility. Overhang of the implant at this area would likely result in poor range of motion or biomechanics.

[0038] In certain embodiments, the plate portion comprises an interfacing surface, wherein the body portion comprises an interfacing surface, wherein in the assembled configuration the interfacing surface of the body portion interfaces with the interfacing surface of the plate portion.

[0039] In certain embodiments, the interfacing surface comprises an engagement feature, wherein the interfacing surface of the body portion comprises an engagement feature, wherein in the assembled configuration the engagement feature of the interfacing surface of the body portion engages with the engagement feature of the interfacing surface of the plate portion. In certain embodiments, one of the engagement feature of the interfacing surface of the body portion and the engagement feature of the interfacing surface of the plate portion is a recessed portion, and wherein the other one of the engagement feature of the interfacing surface of the body portion and the engagement feature of the interfacing surface of the plate portion is a protruding portion.

[0040] Advantageously, providing engagement features at the interface between the body portion and the plate portion helps prevent lateral movement between the template and the trial component. The engagement features also provide haptic feedback to the surgeon that the trial component is fully seated onto the template.

[0041] In certain embodiments, the combined thickness of the plate portion and the trial component is from about 5mm to about 13mm, aptly about 5mm to about 9mm.

[0042] According to another aspect of the invention, a system or kit of parts for arthroplasty comprises: the above described trialling system; and an orthopaedic implant.

[0043] In certain embodiments, the orthopaedic implant comprises a peripheral edge, wherein the shape and size of the peripheral edge of the orthopaedic implant is substantially the same as the peripheral edge of the template and / or the trial component.

[0044] In certain embodiments, the profile of the orthopaedic implant is substantially the same as the profile of the template and / or the trial component.

[0045] In certain embodiments, the orthopaedic implant comprises a plate portion and an insertion feature extending from a surface of the plate portion.

[0046] In certain embodiments, the insertion feature of the trial component has a pre-determined length which is substantially equal to the length of the insertion portion of the orthopaedic implant plus the thickness of the plate portion of the template surrounding the cutting guide. In certain embodiments, the insertion feature of the trial component has a pre-determined profile which is substantially equal to the profile of the insertion portion of the orthopaedic implant.

[0047] In certain embodiments, the thickness of the plate portion of the orthopaedic implant is substantially the same as the combined thickness of the plate portion of the template, the distance gauge portion of the trial component and optionally the one or more secondary distance gauge elements.

[0048] According to another aspect of the invention, a method of manufacturing a trialling system for an orthopaedic implant for arthroplasty comprises: producing a trialling system comprising: a template for attachment to a bone in a joint, the template comprising: a plate portion; and a cutting guide extending through the thickness of the plate portion for guiding a cutting tool for forming a fixation cavity in the bone; and a trial component comprising: a body portion; and an insertion feature extending from a surface of the body portion, wherein the trialling system has an assembled configuration in which: the body portion interfaces with the plate portion; and the insertion feature extends through the cutting guide and protrudes from the plate portion. wherein the trialling system is produced such that the insertion feature has a predetermined length which is substantially equal to an intended depth of the fixation cavity in the bone plus the thickness of the plate portion surrounding the cutting guide.

[0049] In certain embodiments the manufactured trialling system is the trialling system of any embodiment described herein.

[0050] According to another aspect of the invention, a method of preparing a bone of a cadaveric specimen for an orthopaedic implant comprises: positioning a template on a bone in a joint, the template comprising: a plate portion; and a cutting guide extending through the thickness of the plate portion for guiding a cutting tool for forming a fixation cavity in the bone; forming a fixation cavity in the bone, wherein the fixation cavity is formed with a cutting tool guided by the cutting guide in the template; coupling a trial component to the template, wherein the trial component comprises: a body portion; and an insertion feature extending from a surface of the body, wherein when the trial component is coupled to the template: the body portion interfaces with the plate portion; and the insertion feature extends through the cutting guide and protrudes from the plate portion into the fixation cavity.

[0051] In certain embodiments, the template and trial component are those of the trialling system of any embodiment described herein.

[0052] In certain embodiments, the bone is a first bone in the joint, wherein the body portion is a distance gauge portion, wherein when the trial component is coupled to the template the distance gauge portion provides an indication of a distance between the plate portion and a second bone of the joint.

[0053] In certain embodiments, the method further comprises determining dimensions for an orthopaedic implant for arthroplasty based on the indication of the distance between the plate portion and the second bone of the joint.

[0054] According to another aspect of the invention, a method of preparing a bone for an orthopaedic implant, the method comprising: positioning a template on a bone in a joint, the template comprising: a plate portion; and a cutting guide extending through the thickness of the plate portion for guiding a cutting tool for forming a fixation cavity in the bone; forming a fixation cavity in the bone, wherein the fixation cavity is formed with a cutting tool guided by the cutting guide in the template; coupling a trial component to the template, wherein the trial component comprises: a body portion; and an insertion feature extending from a surface of the body, wherein when the trial component is coupled to the template: the body portion interfaces with the plate portion; and the insertion feature extends through the cutting guide and protrudes from the plate portion into the fixation cavity.

[0055] In certain embodiments, the template and trial component are those of the trialling system of any embodiment described herein.

[0056] In certain embodiments, the bone is a first bone in the joint, wherein the body portion is a distance gauge portion, wherein when the trial component is coupled to the template the distance gauge portion provides an indication of a distance between the plate portion and a second bone of the joint.

[0057] In certain embodiments, the method further comprises determining dimensions for an orthopaedic implant for arthroplasty based on the indication of the distance between the plate portion and the second bone of the joint.

[0058] According to another aspect of the invention, a method of fitting an orthopaedic implant comprises: preparing a bone for an orthopaedic implant according to any of the embodiments described herein; and fitting an orthopaedic implant.

[0059] According to another aspect of the invention a method of determining dimensions for an orthopaedic implant for arthroplasty comprises: coupling a trial component to a template positioned on a first bone in a joint, wherein the trial component comprises: a distance gauge portion; and an insertion feature extending from a surface of the body portion, wherein the template comprises: a plate portion; and a cutting guide extending through the thickness of the plate portion for guiding a cutting tool for forming a fixation cavity in the first bone; and wherein when the trial component is coupled to the template: the distance gauge portion interfaces with the plate portion; the insertion feature extends through the cutting guide and protrudes from the plate portion into a fixation cavity in the first bone; and the distance gauge portion provides an indication of a distance between the plate portion and a second bone of the joint; and determining dimensions for an orthopaedic implant for arthroplasty based on the indication of the distance between the plate portion and the second bone of the joint.

[0060] According to another aspect of the invention a method of determining dimensions for an orthopaedic implant for arthroplasty comprises: positioning a template on a first bone in a joint, the template comprising: a plate portion; and a cutting guide extending through the thickness of the plate portion for guiding a cutting tool for forming a fixation cavity in the first bone; forming a fixation cavity in the first bone, wherein the fixation cavity is formed with a cutting tool guided by the cutting guide in the template; coupling a trial component to the template, wherein the trial component comprises: a distance gauge portion; and an insertion feature extending from a surface of the distance gauge portion, wherein when the trial component is coupled to the template: the distance gauge portion interfaces with the plate portion; the insertion feature extends through the cutting guide and protrudes from the plate portion into the fixation cavity; and the distance gauge portion provides an indication of a distance between the plate portion and a second bone of the joint; and determining dimensions for an orthopaedic implant for arthroplasty based on the indication of the distance between the plate portion and the second bone of the joint.

[0061] In certain embodiments, the method further comprises the step of attaching the template to the first bone prior to forming the fixation cavity.

[0062] In any of the aforementioned aspects, either or both of the template and the trial component may comprise a handle. The or each handle may be holdable by a surgeon or other user to insert the template or trial component into the joint during arthroplasty. For the avoidance of doubt, any of the features described herein apply equally to any aspect of the invention. It will be appreciated that anatomical directions used throughout, refer to anatomical directions when the component is in-situ in the intended position and orientation in a patient. That is, posterior, anterior, superior, inferior, lateral and medial have their usual meanings, and refer to when the implant component or the template or the trial component are in-situ in the intended position and orientation in a patient.

[0063] Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, unless such features are incompatible. For the avoidance of doubt, the terms “may”, “and / or”, “e.g.”, “for example” and any similar term as used herein should be interpreted as non-limiting such that any feature so-described need not be present. Indeed, any combination of optional features is expressly envisaged without departing from the scope of the invention, whether or not these are expressly claimed. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner.

[0064] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

[0065] Figures 1 and 2 illustrate views of a template of a trialling system;

[0066] Figure 3 is a view of the template shown in Figures 1 and 2 in the superior direction; Figure 4 is a view of the template shown in Figures 1 and 2 in the inferior direction; Figure 5 is a side view of the template shown in Figures 1 and 2;

[0067] Figures 6 to 9 illustrate views of a trial component for use with the template of Figures 1 to 5;

[0068] Figures 10 to 13 illustrate views of a trialling system for an orthopaedic implant for arthroplasty in an assembled configuration;

[0069] Figures 14 and 15 illustrate a distance gauge element of the trialling system of Figures 10 to 13;

[0070] Figure 16 illustrates the trialling system of Figures 10 to 13 including the distance gauge element of Figures 14 and 15; Figures 17 and 18 illustrate views of an implant component of an orthopaedic implant;

[0071] Figure 19 illustrates a side view of the implant component of Figures 17 and 18; and Figures 20 and 21 are schematic representations of a resected tibia prepared to receive the tibial implant component of any of Figures 17 to 19.

[0072] Figures 1 to 5 illustrate a template 100 for attachment to a bone in a joint. In this example the template 100 is for attachment to a tibia.

[0073] The template 100 includes a plate portion 102. The plate portion 102 is typically flat so as to sit on a flat resected portion of the tibia. The plate portion 102 includes a peripheral edge 120 extending around the periphery of the plate portion 102. The peripheral edge 120 is sized and shaped so as to substantially match a peripheral edge 420 of a corresponding implant component 400, for example that shown in Figures 17 to 19 and described below.

[0074] The template 100 includes a cutting guide extending through the thickness of the plate portion 102. The cutting guide provides a guide for a cutting tool when forming a fixation cavity in the bone. The cutting tool may be a reciprocating saw, a reamer, a drill bit or any other suitable cutting tool. As used herein, a ‘fixation cavity’ refers to a hole or cavity formed in a bone for the purpose of receiving a fixation element - that is, an element used to fix a component to the bone. For example, the fixation elements here may be elements used to fix an implant to the bone.

[0075] In this example, the template 100 includes a plurality of cutting guides, each cutting guide for forming a separate fixation cavity in the bone. The template 100 includes a keel slot guide 104 as a first cutting guide and peg hole guides 106 as second and third cutting guides. It would be understood that the template 100 may include any number of cutting guides depending on the required number of fixation cavities. For example the template 100 may include 1 , 2, 3 or more cutting guides.

[0076] In this example the plate portion 102 includes attachment holes 108 extending through the thickness of the plate portion 102. The attachment holes 108 are configured to receive an attachment element, for example a screw, during attachment of the template 100 to the bone. It would be understood that the template 100 may include any number of attachment holes 108, for example 1 , 3 or more. In use, the template 100 is positioned on the resected tibia by a surgeon. The template 100 is then attached to the resected tibia via attachment elements extending through the attachment holes 108. When the template 100 is fixed to the tibia, the surgeon forms peg holes in the tibia, for example by reaming, using the peg hole guides 106 as a guide. That is, a suitable cutting tool is inserted through the peg hole guides 106 and the peg holes are formed in the bone directly underneath the peg hole guides 106. The resulting peg holes are positioned so as to receive corresponding pegs 406 of the implant component 400. The surgeon also cuts a keel slot, for example with a reciprocating saw, using the keel slot guide 104 as a guide. That is, a suitable cutting tool is inserted through the keel slot guide 104 and the keel slot is formed in the bone directly underneath the keel slot guide 104. The keel slot guide 104 extends in a posterior to anterior direction, in use. The resulting keel slot is positioned so as to receive a corresponding keel 404 of the implant component 400.

[0077] Figure 20 shows a view of a resected tibia looking in an inferior direction, and Figure 21 shows a section view through the tibia in a plane along which the keel lies. As the tibia is prepared for partial knee arthroplasty in this example, there is a resected side TR and a non-resected side TN. The resected side TR is shown with a keel slot 21 formed with a suitable cutting tool using the keel slot guide 104. The keel slot 21 has a posterior end 23 and an anterior end 24. The resected side TR of the tibia also has two peg holes 25 formed with a suitable cutting tool using the peg hole guides 106.

[0078] In this example the template 100 includes a placement element 110 extending from the peripheral edge 120 of the plate portion 102. The placement element 110 allows the surgeon to quickly and accurately place the template 100 on the tibia. Furthermore, the placement element 110 helps ensure the template 100 remains in the intended position during attachment of the template 100 to the tibia. The placement element 110 also ensures that the template 100 is not overhanging at the rear of the knee joint, where there is minimal visibility. Overhang of the implant at this area would likely result in poor range of motion or biomechanics.

[0079] Figures 6 to 9 illustrate a trial component 200 for use with the template of Figures 1 to 5. The trial component 200 includes a body portion 202. The body portion 202 is a planar portion, which in this example is flat so as to match the plate portion 102. The body portion 202 includes a peripheral edge 220 extending around the periphery of the body portion 202. The peripheral edge 220 is sized and shaped so as to substantially match the peripheral edge 120 of the plate portion 102 and therefore also the peripheral edge 420 of the implant component 400.

[0080] The trial component 200 includes an insertion feature, otherwise termed a bone-insertion feature. The body portion 202 includes an interfacing surface 203, that is a lower surface or inferior surface of the body portion 202 in use (best shown in Figure 8). The insertion feature extends from the interfacing surface 203 of the body portion 202. That is, the insertion feature extends out of the plane of the body portion 202.

[0081] In this example the trial component 200 includes a plurality of insertion features, each insertion feature corresponding to a cutting guide of the template 100. The trial component 200 includes a trial keel component 204 as a first insertion feature and trial pegs 206 as second and third insertion features. It would be understood that the trial component 200 may include any number of insertion features depending on the required number of cutting guides. For example the trial component 200 may include 1 , 2, 3 or more insertion features.

[0082] The insertion features are positioned on the interfacing surface 203 of the body portion 202 such that when the template 100 is aligned with the trial component 200 the insertion features are aligned with, and insertable through, the corresponding guide. That is, the trial keel component 204 is insertable through the keel slot guide 104. Similarly the trial pegs 206 are insertable through the peg hole guides 106.

[0083] Figures 10 to 13 illustrate a trialling system 1000 for an orthopaedic implant for knee arthroplasty or partial knee arthroplasty. The trialling system 1000 includes the template 100 and the trial component 200. Figures 10 to 13 illustrate the trialling system 1000 in an assembled configuration. In the assembled configuration the body portion 202 interfaces with the plate portion 102. The plate portion 102 includes an interfacing surface 103, that is an upper surface or superior surface of the plate portion 102 in use (best shown in Figures 3 and 5). In the assembled configuration the interfacing surface 103 of the plate portion 102 interfaces with and engages the interfacing surface 203 of the body portion 202. In the assembled configuration the peripheral edge 120 of the template 100 is aligned with the peripheral edge 220 of the trial component 200. As such, the assembled trialling system 1000 mimics the implant component 400 to be used.

[0084] In this example the interfacing surface 103 of the plate portion 102 and the interfacing surface 203 of the body portion 202 each include an engagement feature. In the assembled configuration the engagement feature of the interfacing surface 203 of the body portion 202 engages with the engagement feature of the interfacing surface 103 of the plate portion 102. Providing engagement features at the interface between the body portion 202 and the plate portion 102 helps prevent lateral movement between the template 100 and the trial component 200 and ensures the body portion 202 is seated correctly with respect to the plate portion 102.

[0085] In this example the engagement feature of the interfacing surface 203 of the body portion 202 is a protruding portion 207 (as best shown in Figure 9). That is, the engagement feature is a protruding portion 207 that protrudes from surrounding parts of the interfacing surface 203. The engagement feature of the interfacing surface 103 of the plate portion 102 is a recessed portion 107 configured to receive the protruding portion 207. That is the engagement feature is a recessed portion 107 that is recessed from surrounding parts of the interfacing surface 103. It would be understood that the engagement feature of the interfacing surface 203 of the body portion 202 may instead be a recessed portion and the engagement feature of the interfacing surface 103 of the plate portion 102 may instead be a protruding portion.

[0086] In the assembled configuration, the insertion features each extend through a corresponding cutting guide and protrude from the plate portion 102. That is, the trial keel component 204 extends through the keel slot guide 104 and protrudes from a lower surface of the plate portion 102. Similarly, the trial pegs 206 each extend through the corresponding peg hole guides 106 and protrude from the lower surface of the plate portion 102.

[0087] In this example, the body portion 202 includes an access groove 209 and an access hole 208 extending through the thickness of the body portion 202. In the assembled configuration, the access groove 209 and the access hole 208 are each aligned with an attachment hole 108. That is, the access groove 209 and the access hole 208 are each coaxial with an attachment hole 108. As such the attachment elements, attaching the template 100 to the underlying bone through the attachment holes 108, are accessible (via the access groove 209 and access hole 208) when the trialling system 1000 is in the assembled configuration. As such, the trial component 200 and template 100 can be removed simultaneously from the underlying bone.

[0088] In use, once the keel slot 21 and peg holes 25 have been formed using the template 100 as a guide, the trial component 200 is coupled to the template 100, into the assembled configuration shown in Figures 10 to 13.

[0089] This allows the depth of the keel slot 21 and peg holes 25 to be measured while the template 100 remains in-situ. That is, the template 100 can be used for bone preparation and while the template 100 remains in-situ, the trial component 200 can be coupled thereto to allow the dimensions of the formed keel slot 21 and peg holes 25 to be checked. As such, suboptimal preparation of the keel slot 21 and / or peg holes 25 is identifiable whilst the template 100 remains in-situ so that a surgeon does not need to reattach the template 100 if they subsequently discover that the keel slot and / or peg holes is suboptimal. As such, the process of fitting the orthopaedic implant 400 is made more efficient.

[0090] In this example the trial keel component 204 has a pre-determined length which is substantially equal to an intended depth of the keel slot 21 plus the thickness of the plate portion 102 surrounding the keel slot guide 104. Similarly, the trial pegs 206 have a predetermined length which is substantially equal to an intended depth of the peg holes 25 plus the thickness of the plate portion 102 surrounding the peg hole guides 106. Put another way, the trial keel component 204 has a pre-determined length which is substantially equal to a depth of the keel 404 plus the thickness of the plate portion 102 surrounding the keel slot guide 104. Similarly, the trial pegs 206 have a pre-determined length which is substantially equal to the pegs 406 plus the thickness of the plate portion 102 surrounding the peg hole guides 106. As such, in use the trial component 200 checks that the depth of the keel slot 21 matches the depth of the keel 404. Similarly, the trial component 200 checks that the depth of the peg holes 25 matches the depth of the pegs 406.

[0091] In this example the trial keel component 204 has a pre-determined shape or profile which is substantially the same as the intended profile of the keel slot 21. Similarly, the trial pegs 206 have a pre-determined length shape or profile which is substantially the same as the intended profile of the peg holes 25. Put another way, the trial keel component 204 has a pre-determined shape or profile which is substantially the same as the keel 404. Similarly, the trial pegs 206 have a pre-determined length shape or profile which is substantially the same as the pegs 406. As such, in use the trial component 200 checks that the shape or profile of the keel slot 21 matches the shape or profile of the keel 404. Similarly, the trial component 200 checks that the shape or profile of the peg holes 25 matches the shape or profile of the pegs 406.

[0092] In this example, the body portion 202 is a distance gauge portion, which may be otherwise termed a spacer portion or a distance indicator. That is, the distance gauge portion 202 provides an indication of a distance from the interfacing surface 103 of the plate portion 102.

[0093] In use, with the template 100 being attached to the tibia, the distance gauge portion 202 provides an indication of a distance between the plate portion 102 and the femur. That is, the surgeon is provided with a visual indication of any space that exists between the plate portion 102 and the femur. As such the surgeon can make a judgement as to whether an implant component 400 having the same thickness as the combined thickness of the template 100 and the trial component 200 is appropriate for that particular patient. Put another way, the surgeon can determine dimensions for an orthopaedic implant for arthroplasty based on an indication of a distance between the plate portion 102 and the femur provided by the distance gauge portion 202. If the surgeon is satisfied that the combined thickness of the template 100 and the trial component 200 is appropriate for that particular patient, the trialling system 1000 is removed from the tibia. The surgeon can then select and fit an implant component 400 with dimensions informed by the surgeons assessment of the trialling system 1000.

[0094] In this example, the distance gauge portion 202 has a thickness of from about 2mm to about 10mm, aptly from 2.5mm to about 9mm, aptly 3mm. In this example, the combined thickness of the plate portion 102 and the trial component 200 is from about 5mm to about 13mm.

[0095] Advantageously, the trialling system 1000 allows both (1) the distance between first and second bones in a joint; and (2) the depth of the fixation cavity to be measured with a single system. That is, the template 100 can be used for bone preparation and while the template 100 remains in-situ, the trial component 200 can be coupled thereto to allow the dimensions of the formed fixation cavity to be checked. The trial component 200, or more specifically the distance gauge portion 202 of the trial component 200, also provides the surgeon with an indication of the distance between the first and second bones in the joint so that the surgeon can determine the correct dimensions for an orthopaedic implant. As such, the process of determining the correct dimensions for an orthopaedic implant and also the process of fitting an orthopaedic implant is made more efficient.

[0096] Figures 14 and 15 illustrate a secondary distance gauge element 300 for use as part of the trialling system of Figures 10 to 13. The secondary distance gauge element 300 may be otherwise termed a spacer element, a shim or a packer element. The secondary distance gauge element 300 is configured to interface with the distance gauge portion 202. That is, in the assembled configuration the secondary distance gauge element 300 interfaces with the distance gauge portion 202 as shown in Figure 16.

[0097] In particular, an upper surface or superior surface 221 of the distance gauge portion 202, that is the opposing surface of the distance gauge portion 202 to the interfacing surface 203, interfaces with a lower or inferior surface 321 of the secondary distance gauge element 300.

[0098] The secondary distance gauge element 300 can be used to pack out the distance between the distance gauge portion 202 and the femur, where required. As such, where a surgeon finds that the combined thickness of the template 100 and the trial component 200 is less than the required thickness for an orthopaedic implant, the surgeon can use one or more additional secondary distance gauge elements 300 to increase the thickness of the trialling system 1000 so as to approximate the required thickness for the orthopaedic implant.

[0099] The upper surface 221 of the distance gauge portion 202 includes an engagement feature 210. The engagement feature 210 is configured to engage with a corresponding engagement feature 310 on the lower surface 321 of the secondary distance gauge element 300. In this example, the engagement feature 310 on the lower surface 321 of the secondary distance gauge element 300 is a protrusion and the engagement feature 210 on the upper surface 221 of the distance gauge portion 202 is a groove or slot configured to receive the protrusion of the secondary distance gauge element 300. Advantageously, providing corresponding engagement, or mating, features in each of the distance gauge portion 202 and the secondary distance gauge element 300, allows the secondary distance gauge element 300 to be substantially locked in place during use. This ensures the trialling system 1000 effectively mimics a unitary implant. The engagement features also provide haptic feedback to the surgeon that the secondary distance gauge element 300 is fully seated onto the trial component 200. It is particularly advantageous for the engagement feature 210 on the upper surface 221 of the distance gauge portion 202 to be a groove or slot, rather than a protrusion. As such, the upper surface 221 can be remain substantially flat so as to best mimic the corresponding implant component.

[0100] In some examples the trialling system 1000, or a kit of parts for providing the trialling system 1000, may include a plurality of secondary distance gauge elements 300. As such, the surgeon can add secondary distance gauge elements 300 to the trial component 200 until they are satisfied that the combined thickness of the template 100, the trial component 200 and the secondary distance gauge elements 300 is appropriate for the depth of a tibial implant component. Alternatively, or in addition, the surgeon can remove secondary distance gauge elements 300 and replace them with secondary distance gauge elements 300 of different thickness. As such, the surgeon may be provided with a set of secondary distance gauge elements 300 of the same thickness or a set of secondary distance gauge elements 300 of different thicknesses.

[0101] In the illustrated example an upper or superior surface of the secondary distance gauge elements 300 each include a groove or slot 330 of the same or similar geometry to the groove or slot on the upper surface 221 of the distance gauge portion 202. The groove or slot 330 is configured to receive the protrusion 310 on the lower surface 321 of the secondary distance element 300. As such, where multiple secondary distance gauge elements 300 are used these will lock into place in the same manner as a secondary distance gauge element 300 locks into place with the distance gauge element 200.

[0102] In this example, the secondary distance gauge elements 300 each include a handle 325 to help the surgeon fit the secondary distance gauge element 300 into the limited space between the distance gauge element 200 and the femur. In this example the handle 325 extends coaxially with the protrusion 310 so that the surgeon is clear on the direction of insertion of the secondary distance gauge element 300. In this example, the secondary distance gauge elements 300 each include an access hole 308 extending through the thickness of the secondary distance gauge element 300. In the assembled configuration, the access hole 308 is aligned with the attachment hole 108 and the access hole 208. As such the attachment elements, attaching the template 100 to the underlying bone through the attachment holes 108, are accessible when the trialling system 1000 is in the assembled configuration. As such, the trial component 200, template 100 and the secondary distance gauge elements 300 can be removed simultaneously from the underlying bone.

[0103] Figures 17 to 19 illustrate a tibial implant component 400 for an orthopaedic implant for partial knee arthroplasty. It will be appreciated that anatomical directions used to describe this tibial implant component 400 relate to anatomical directions when the tibial implant component is correctly installed in a patient. More specifically, “lateral”, “medial”, “posterior”, “anterior”, “superior” and “inferior” all have their usual anatomical meanings, and relate to the respective direction when the tibial implant component 400 is located in the patient.

[0104] The tibial implant component 400 has a plate portion 402 which has a bone interfacing side B. The tibial implant component 400 has a keel 404 extending from the bone interfacing side B of the plate portion 11. The keel 404 extends from the bone-interfacing side B in an inferior direction, in use. The keel 404 is configured to be inserted into the keel slot 21. In the example of Figures 17 to 19 the keep 404 is trapezoidal in shape. However, it would be understood that the keel 404 may be of any suitable size or shape / profile.

[0105] In this example, the tibial implant component 400 has two bone-insertion pegs 406 extending from the bone-interfacing side B of the plate portion 402. The bone insertion pegs 406 are configured to be received in reamed holes in the tibia of the patient. Each peg 406 extends away from the bone-interfacing side B with a posterior direction component.

[0106] A superior side of the plate portion 402 provides a second side A for interfacing with an articulating joint component (not shown), for example a polymer articulating joint component. The articulating joint component, in this example, is configured for articulation with an articulation surface of a femoral component (not shown) or of a femur (not shown). The second side A is on the opposite side of the plate portion 402 to the bone-interfacing side B. The orthopaedic implant 400 includes a peripheral edge 420, wherein the shape and size of the peripheral edge 420 of the orthopaedic implant 400 is substantially the same as the peripheral edge 120 of the template 100 and / or the peripheral edge 220 of the trial component 200. The profile of the orthopaedic implant 400 is substantially the same as the profile of the template 100 and / or the trial component 200.

[0107] The thickness of the plate portion 402 of the orthopaedic implant 400 is substantially the same as the combined thickness of the plate portion 102, the distance gauge portion 202 and optionally the thickness of one or more secondary distance gauge elements 300 according to the surgeons determination of the required size for the orthopaedic implant 400 based on the trialling system 1000.

[0108] In this example the tibial implant component 400 is unitary and metallic, for example produced using a titanium alloy, for example Ti64. However, other suitable materials may be used.

[0109] Referring again to Figures 20 and 21 , after preparing the tibia for receiving the tibial implant component 400 and checking the prepared tibia with the trial component 200, the surgeon operating from the anterior side of the knee, inserts the keel 404 into the keel slot 21 . Also, during this motion, the pegs 406 are received in the respective holes 25 in the tibia. When the tibial implant component 400 is in place on the tibia, the bone-interfacing side B of the plate portion 402 is in contact with an interfacing surface 22 of the resected side TR of the tibia.

[0110] It would be understood that the tibial implant component 400 or a selection of tibial implant components 400, each having a range of thicknesses may be provided with the aforementioned trialling system 1000 as a system or kit of parts for arthroplasty.

[0111] In another example, only a keel slot guide is present in the template, as a cutting guide, and there are no peg hole guides. In a further example, only one or more peg hole is present in the template, as one or more cutting guide, and there is no keel slot. In another example, either or both of the template and the trial component has a handle. The or each handle is holdable by a surgeon or other user to insert the template or trial component into the joint during arthroplasty. It will be appreciated by those skilled in the art that, whilst the embodiments of this invention are presented with reference to a tibial component for partial knee arthroplasty, the advantage would also be realised in tibial components used for total knee arthroplasty. In such an embodiment, the tibial component has a plate portion which is configured to interface with an entire resected tibia. In addition, it will be appreciated by those skilled in the art that, whilst the embodiments of this invention are presented with reference to components for knee arthroplasty, the advantage would also be realised in components for arthroplasty of other joints.

[0112] It will be appreciated by those skilled in the art that any number of combinations of the aforementioned features and / or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.

[0113] The following numbered clauses are provided:

[0114] Clause 1 . A trialling system for an orthopaedic implant for arthroplasty, the trialling system comprising: a template for attachment to a bone in a joint, the template comprising: a plate portion; and a cutting guide extending through the thickness of the plate portion for guiding a cutting tool for forming a fixation cavity in the bone; and a trial component comprising: a body portion; and an insertion feature extending from a surface of the body portion, wherein the trialling system has an assembled configuration in which: the body portion interfaces with the plate portion; and the insertion feature extends through the cutting guide and protrudes from the plate portion. Clause 2. The trialling system according to clause 1 , wherein the insertion feature has a pre-determined length which is substantially equal to an intended depth of the fixation cavity in the bone plus the thickness of the plate portion surrounding the cutting guide.

[0115] Clause 3. The trialling system according to any preceding clause, wherein the body portion is a distance gauge portion.

[0116] Clause 4. The trialling system according to clause 3, wherein in use in the assembled configuration with the template being attached to a first bone in a joint, the distance gauge portion provides an indication of a distance between the plate portion and a second bone of the joint. Clause 5. The trialling system according to clause 3 or clause 4, wherein the distance gauge portion has a thickness of from about 2mm to about 10mm.

[0117] Clause 6. The trialling system according to any of clauses 3 to 5, wherein the trialling system comprises one or more secondary distance gauge elements configured to interface with the distance gauge portion.

[0118] Clause 7. The trialling system according to clause 6, wherein in the assembled configuration a secondary distance gauge element of the one or more secondary distance gauge elements interfaces with the distance gauge portion.

[0119] Clause 8. The trialling system according to clause 6 or clause 7, wherein the one or more secondary distance gauge elements comprises a plurality of secondary distance gauge elements, wherein each secondary distance gauge element of the one or more secondary distance gauge elements is of a different thickness.

[0120] Clause 9. The trialling system according to any of clauses 6 to 8, wherein an upper surface of the distance gauge portion comprises an engagement feature configured to engage with a corresponding engagement feature on a lower surface of the one or more secondary distance gauge elements.

[0121] Clause 10. The trialling system of clause 9, wherein the engagement feature of the one or more secondary distance gauge elements comprises a protrusion, wherein the engagement feature of the distance gauge portion comprises a groove or slot configured to receive the protrusion of the one or more secondary distance gauge elements.

[0122] Clause 11. The trialling system according to any preceding clause, wherein the cutting guide comprises a keel slot guide and the insertion feature comprises a trial keel component.

[0123] Clause 12. The trialling system according to clause 11 , wherein the trial keel component has a profile which corresponds to the intended profile of the fixation cavity, such that the trial keel component is insertable through the keel slot guide to test the profile of a fixation cavity formed in the bone.

[0124] Clause 13. The trialling system according to any of clauses 1 to 10, wherein the cutting guide comprises a peg hole guide and the insertion feature comprises a trial peg.

[0125] Clause 14. The trialling system according to any preceding clause, wherein the template comprises two or more cutting guides extending through the thickness of the plate portion and the trial component comprises two or more insertion features, wherein in the assembled configuration each insertion feature of the two or more insertion features extends through a corresponding cutting guide of the two or more cutting guides and protrudes from the plate portion. Clause 15. The trialling system according to any preceding clause, wherein the trialling system is for an orthopaedic implant for knee arthroplasty or partial knee arthroplasty, wherein the template is for attachment to a tibia.

[0126] Clause 16. The trialling system according to any preceding clause, wherein the plate portion comprises an attachment hole extending through the thickness of the plate portion, the attachment hole being configured to receive an attachment element.

[0127] Clause 17. The trialling system according to clause 16, wherein the body portion comprises an access groove or access hole extending through the thickness of the body portion, wherein in the assembled configuration the attachment hole and the access groove or access hole are aligned.

[0128] Clause 18. The trialling system according to any preceding clause, wherein the plate portion comprises a peripheral edge, wherein the template comprises a placement element extending from the peripheral edge of the plate portion.

[0129] Clause 19. The trialling system according to any preceding clause, wherein the plate portion comprises an interfacing surface, wherein the interfacing surface of the plate portion comprises an engagement feature, wherein the body portion comprises an interfacing surface, wherein the interfacing surface of the body portion comprises an engagement feature, wherein in the assembled configuration: the interfacing surface of the body portion interfaces with the interfacing surface of the plate portion, and the engagement feature of the interfacing surface of the body portion engages with the engagement feature of the interfacing surface of the plate portion.

[0130] Clause 20. The trialling system according to clause 19, wherein one of the engagement feature of the interfacing surface of the body portion and the engagement feature of the interfacing surface of the plate portion is a recessed portion, and wherein the other one of the engagement feature of the interfacing surface of the body portion and the engagement feature of the interfacing surface of the plate portion is a protruding portion.

[0131] Clause 21. The trialling system of any preceding clause, wherein the combined thickness of the plate portion and the body portion is from about 5mm to about 13mm.

[0132] Clause 22. A method of manufacturing a trialling system for an orthopaedic implant for arthroplasty comprises: producing a trialling system comprising: a template for attachment to a bone in a joint, the template comprising: a plate portion; and a cutting guide extending through the thickness of the plate portion for guiding a cutting tool for forming a fixation cavity in the bone; and a trial component comprising: a body portion; and an insertion feature extending from a surface of the body portion, wherein the trialling system has an assembled configuration in which: the body portion interfaces with the plate portion; and the insertion feature extends through the cutting guide and protrudes from the plate portion, wherein the trialling system is produced such that the insertion feature has a predetermined length which is substantially equal to an intended depth of the fixation cavity in the bone plus the thickness of the plate portion surrounding the cutting guide.

[0133] Clause 23. A method of preparing a bone of a cadaveric specimen for an orthopaedic implant, the method comprising: positioning a template on a bone in a joint of a cadaveric specimen, the template comprising: a plate portion; and a cutting guide extending through the thickness of the plate portion for guiding a cutting tool for forming a fixation cavity in the bone; forming a fixation cavity in the bone, wherein the fixation cavity is formed with a cutting tool guided by the cutting guide in the template; coupling a trial component to the template, wherein the trial component comprises: a body portion; and an insertion feature extending from a surface of the body, wherein when the trial component is coupled to the template: the body portion interfaces with the plate portion; and the insertion feature extends through the cutting guide and protrudes from the plate portion into the fixation cavity.

[0134] Clause 24. A method according to clause 23, wherein the bone is a first bone in the joint, wherein the body portion is a distance gauge portion, wherein when the trial component is coupled to the template the distance gauge portion provides an indication of a distance between the plate portion and a second bone of the joint. Clause 25. A method according to clause 24, wherein the method further comprises determining dimensions for an orthopaedic implant for arthroplasty based on the indication of the distance between the plate portion and the second bone of the joint.

Claims

CLAIMS1. A trialling system for an orthopaedic implant for knee arthroplasty or partial knee arthroplasty, the trialling system comprising: a template for attachment to a tibia in a knee joint, the template comprising: a plate portion; and a cutting guide extending through the thickness of the plate portion for guiding a cutting tool for forming a fixation cavity in the tibia; and a trial component comprising: a body portion which is a distance gauge portion having a thickness of from 2 mm to 10 mm; and an insertion feature extending from a surface of the body portion, wherein the trialling system has an assembled configuration in which: the body portion interfaces with the plate portion; and the insertion feature extends through the cutting guide and protrudes from the plate portion; wherein in use in the assembled configuration with the template being attached to the tibia in the knee joint, the distance gauge portion provides an indication of a distance between the plate portion and a femur of the knee joint.

2. The trialling system according to claim 1 , wherein the insertion feature has a predetermined length which is substantially equal to an intended depth of the fixation cavity in the bone plus the thickness of the plate portion surrounding the cutting guide.

3. The trialling system according to any preceding claim, wherein the trialling system comprises one or more secondary distance gauge elements configured to interface with the distance gauge portion.

4. The trialling system according to claim 3, wherein in the assembled configuration a secondary distance gauge element of the one or more secondary distance gauge elements interfaces with the distance gauge portion.

5. The trialling system according to claim 3 or claim 4, wherein the one or more secondary distance gauge elements comprises a plurality of secondary distancegauge elements, wherein each secondary distance gauge element of the one or more secondary distance gauge elements is of a different thickness.

6. The trialling system according to any of claims 6 to 5, wherein an upper surface of the distance gauge portion comprises an engagement feature configured to engage with a corresponding engagement feature on a lower surface of the one or more secondary distance gauge elements.

7. The trialling system of claim 6, wherein the engagement feature of the one or more secondary distance gauge elements comprises a protrusion, wherein the engagement feature of the distance gauge portion comprises a groove or slot configured to receive the protrusion of the one or more secondary distance gauge elements.

8. The trialling system according to any preceding claim, wherein the cutting guide comprises a keel slot guide and the insertion feature comprises a trial keel component.

9. The trialling system according to claim 8, wherein the trial keel component has a profile which corresponds to the intended profile of the fixation cavity, such that the trial keel component is insertable through the keel slot guide to test the profile of a fixation cavity formed in the bone.

10. The trialling system according to any of claims 1 to 7, wherein the cutting guide comprises a peg hole guide and the insertion feature comprises a trial peg.

11. The trialling system according to any preceding claim, wherein the template comprises two or more cutting guides extending through the thickness of the plate portion and the trial component comprises two or more insertion features, wherein in the assembled configuration each insertion feature of the two or more insertion features extends through a corresponding cutting guide of the two or more cutting guides and protrudes from the plate portion.

12. The trialling system according to any preceding claim, wherein the plate portion comprises an attachment hole extending through the thickness of the plate portion, the attachment hole being configured to receive an attachment element.

13. The trialling system according to claim 12, wherein the body portion comprises an access groove or access hole extending through the thickness of the body portion, wherein in the assembled configuration the attachment hole and the access groove or access hole are aligned.

14. The trialling system according to any preceding claim, wherein the plate portion comprises a peripheral edge, wherein the template comprises a placement element extending from the peripheral edge of the plate portion.

15. The trialling system according to any preceding claim, wherein the plate portion comprises an interfacing surface, wherein the interfacing surface of the plate portion comprises an engagement feature, wherein the body portion comprises an interfacing surface, wherein the interfacing surface of the body portion comprises an engagement feature, wherein in the assembled configuration: the interfacing surface of the body portion interfaces with the interfacing surface of the plate portion, and the engagement feature of the interfacing surface of the body portion engages with the engagement feature of the interfacing surface of the plate portion.

16. The trialling system according to claim 15, wherein one of the engagement feature of the interfacing surface of the body portion and the engagement feature of the interfacing surface of the plate portion is a recessed portion, and wherein the other one of the engagement feature of the interfacing surface of the body portion and the engagement feature of the interfacing surface of the plate portion is a protruding portion.

17. The trialling system of any preceding claim, wherein the combined thickness of the plate portion and the body portion is from about 5mm to about 13mm.

18. A method of manufacturing a trialling system for an orthopaedic implant for knee arthroplasty or partial knee arthroplasty comprising: producing a trialling system comprising: a template for attachment to a tibia in a knee joint, the template comprising: a plate portion; and a cutting guide extending through the thickness of the plate portion for guiding a cutting tool for forming a fixation cavity in the tibia; and a trial component comprising: a body portion which is a distance gauge portion having a thickness of from 2 mm to 10 mm; and an insertion feature extending from a surface of the body portion, wherein the trialling system has an assembled configuration in which: the body portion interfaces with the plate portion; and the insertion feature extends through the cutting guide and protrudes from the plate portion; wherein the trialling system is produced such that the insertion feature has a predetermined length which is substantially equal to an intended depth of the fixation cavity in the bone plus the thickness of the plate portion surrounding the cutting guide; and wherein the trialling system is produced such that, when in use in the assembled configuration with the template being attached to the tibia in the knee joint, the distance gauge portion provides an indication of a distance between the plate portion and a femur of the knee joint.

19. A method of preparing a bone of a cadaveric specimen for an orthopaedic implant, the method comprising: positioning a template on a tibia in a knee joint of a cadaveric specimen, the template comprising: a plate portion; and a cutting guide extending through the thickness of the plate portion for guiding a cutting tool for forming a fixation cavity in the tibia; forming a fixation cavity in the tibia, wherein the fixation cavity is formed with a cutting tool guided by the cutting guide in the template;coupling a trial component to the template, wherein the trial component comprises: a body portion which is a distance gauge portion having a thickness of from 2 mm to 10 mm; and an insertion feature extending from a surface of the body, wherein when the trial component is coupled to the template: the body portion interfaces with the plate portion; and the insertion feature extends through the cutting guide and protrudes from the plate portion into the fixation cavity; and wherein when the trial component is coupled to the template the distance gauge portion provides an indication of a distance between the plate portion and a femur of the knee joint20. A method according to claim 19, wherein the method further comprises determining dimensions for an orthopaedic implant for arthroplasty based on the indication of the distance between the plate portion and the second bone of the joint.

Images