Method for selecting a patellar prosthesis corresponding to the patient's morphotype in a system of prosthetic families

Abstract

A computer-executable method for selecting a patellar prosthesis (1) is performed by acquiring a 3D model of a knee joint, specifically a patella, of a patient at a pre-operative stage. A number of parameters identifying the structure of the patella are measured / acquired on this model. These parameters are used to query a database in order to identify the prosthesis (1) that best approximates the structure of the patella. The patellar prosthesis (1) with the highest number of matches is then selected based on a match between the measured parameters and those in the database. Also proposed is an arthroplasty system comprising a plurality of prostheses (1) subdivided into families according to respective identifying parameters that allow the identification of the specific prosthesis (1) that best meets and adapts to the patient's needs and morphotype.

Description

[0001] METHOD FOR SELECTING A PATELLAR PROSTHESIS CORRESPONDING TO THE PATIENT’S MORPHOTYPE IN A SYSTEM OF PROSTHETIC FAMILIES

[0002] The present invention relates to the technical field of medical devices, specifically prostheses, and methods for their identification and selection.

[0003] In particular, the present invention relates to a method for selecting a patellar prosthesis, as well as a system for knee arthroplasty that can optimise the processes of identifying and selecting a specific prosthesis according to the needs of the operator and the patient.

[0004] In general, as part of a bone reconstruction operation it is necessary to make a series of cuts in the bone to allow the subsequent insertion and coupling of a prosthesis replicating the conformation of the damaged bone structure in need of replacement.

[0005] In order to minimise patient discomfort and optimise the post-operative recovery and rehabilitation process, it is known to perform a design process according to which a personalised prosthesis is generated for the individual patient, specifically modelled on the basis of the patient’s bone measurements as well as the geometry of the specific cuts to be made during the operation.

[0006] This approach is particularly followed in the context of knee joint reconstruction operations that can be performed according to the kinematic alignment (KA) approach, for example.

[0007] According to this technique, the aim is to reconstruct the specific alignment of the patient’s limbs as well as completely restoring their biomechanical situation based on the specific kinematic axes of the actual patient.

[0008] In this context, the fabrication of a personalised prosthesis is particularly advantageous in order to achieve as faithful a replica of the pre-operative joint situation as possible.

[0009] However, it is clear that such a procedure is extremely onerous and complex both in terms of cost and timing. In fact, the creation of a prosthesis with this level of personalisation requires work specifically designed around the patient’s bone measurements, thus leading to the generation of an essentially unique piece.

[0010] There is thus a strong need in the sector to develop new operating methods, as well as new tools, capable of providing a more generalised and universally applicable approach and solutions without losing the advantages guaranteed by the current level of personalisation, thanks to which a satisfactory structural correspondence between the implanted prosthesis and the bone structure it replaces is guaranteed.

[0011] In this context, the technical task underlying the present invention is in particular to propose a method for selecting a patellar prosthesis that overcomes at least some of the drawbacks of the prior art mentioned above.

[0012] In particular, it is the object of the present invention to provide a method that can reduce the time and cost of selecting and obtaining a prosthesis, while maintaining an optimal match between the selected prosthesis and the bone structure to be repaired.

[0013] The technical task set and the objects specified are substantially attained by a method, comprising the technical characteristics as set out in one or more of the accompanying claims.

[0014] According to the present invention, a computer-executable method for selecting a patellar prosthesis is shown.

[0015] The method is performed by acquiring a 3D model of a patient’s knee joint at a pre-operative stage.

[0016] In particular, the 3D model represents and identifies the patient’s patella, specifically representing its shape and size.

[0017] A plurality of identifying parameters including at least one engagement parameter and one bone parameter are then measured on the 3D model.

[0018] The engagement parameter is representative of a size of a portion of the patellar prosthesis adapted to engage the patella according to one or more cutting lines to be performed on that bone.

[0019] The bone parameter is representative of a shape of a portion of the patellar prosthesis adapted to engage a femoral component of the knee joint.

[0020] The bone parameter then defines the shape of the patellar prosthesis portions that will replace corresponding patella portions in use.

[0021] A database comprising prosthetic data identifying a plurality of patellar prostheses according to their respective identifying parameters is then queried.

[0022] Advantageously, patellar prostheses are divided into a plurality of distinct families, with each patellar prosthesis having the same engagement parameter as each other patellar prosthesis in the same family and at least one different bone parameter from a corresponding bone parameter of at least one other prosthesis in the same family.

[0023] Finally, a patellar prosthesis with the highest number of matches between its identifying parameters and those measured on the 3D image is selected from the database.

[0024] Advantageously, the method presented here makes it possible to precisely, quickly and accurately identify the specific patellar prosthesis that best fits the patient’s anatomy.

[0025] A system and a database are also described and claimed.

[0026] The system comprises a plurality of patellar prostheses identified by respective identifying parameters.

[0027] Patellar prostheses are also subdivided into families according to these identifying parameters.

[0028] The database stores prosthetic data identifying a plurality of patellar prostheses belonging to the system.

[0029] The dependent claims, which are incorporated herein for reference, correspond to different embodiments of the invention.

[0030] Further features and advantages of the present invention will become more apparent from the approximate and thus non-limiting description of a preferred, but non-exclusive, embodiment of a method for selecting a patellar prosthesis, as shown in the accompanying drawings, wherein:

[0031] - Figure 1 shows a knee prosthesis in general;

[0032] - Figures 2A-2B show a possible embodiment for a patellar prosthesis in more detail, in a side and top view, respectively.

[0033] - Figure 3 illustrates possible types of patellar prostheses.

[0034] The method described herein allows for a particularly efficient and precise selection of a patellar prosthesis 1 , otherwise known as a patella, for use during a bone reconstruction operation.

[0035] This method is particularly used in the selection of a prosthesis 1 for the reconstruction of a patella, or patellar bone, particularly for the reconstruction of the joint defined between the patella and a distal end of the patient’s femur.

[0036] The method is executable by a computer, i.e. any electronic device comprising one or more processing units, processors, electronic components equipped with the calculation and input manipulation capabilities required to correctly execute the various steps that define the method itself and for which a detailed description will be provided below.

[0037] In this context, the claimed method is performed by acquiring a three- dimensional model of a patient’s knee joint at a pre-operative stage.

[0038] In other words, information is acquired by means of known methods (e.g. by means of a tomographic technique or by reconstructing a three- dimensional model from two-dimensional X-ray images or even by means of magnetic resonance techniques), information which makes it possible to generate and acquire a three-dimensional representation of the knee joint on which the bone repair operation is to be performed.

[0039] In particular, the 3D model at least illustrates the shape and size of the patella that is part of this knee joint, allowing both its structure to be identified and the way in which it is coupled and cooperates with the distal end of the femur on which it slides.

[0040] Once the image has been acquired, a number of identifying parameters are measured in the 3D model.

[0041] Identifying parameters are generally parameters that make it possible to determine and categorise specific structural and dimensional features of the patella so that the patellar prosthesis 1 that best reproduces and / or approximates these features can subsequently be identified.

[0042] In particular, the identifying parameters make it possible to identify the structural characteristics of the patella that determine its coupling with the distal end of the femur.

[0043] In more detail, the identifying parameters include at least one engagement parameter and at least one bone parameter.

[0044] In this context, the engagement parameter is a representative parameter of a size of a portion of the patellar prosthesis adapted to engage the patella as a function of one or more cutting lines to be performed on said bone.

[0045] In fact, in a bone reconstruction operation it is necessary to make cuts in the patient’s patella to allow the housing and coupling of the prosthesis 1 (which in turn replicates or contributes to replicating the bone structure that was removed as a result of these cuts).

[0046] The bone parameter, on the other hand, is representative of a shape of a portion of the patellar prosthesis 1 adapted to engage a femoral component of the knee joint.

[0047] This femoral component can be defined, for example, by a femoral prosthesis F in turn cooperating with a tibial prosthesis T, as seen in Figure 1 .

[0048] Thus, the engagement parameter identifies the size of the prosthesis 1 and thus of the bone surface on which it will abut in a use configuration or in any case a size of the portions of prosthesis 1 configured to be constrained with the patella being repaired, while the bone parameter identifies a conformation of the portion of the patella that is replaced by the prosthesis 1 , in particular of the portion of the outer surface of the patella that engages the femoral component. In general, the engagement parameter comprises at least one of: a length L1 of the prosthesis 1 , a width L2 of the prosthesis 1 (otherwise known as the mid-lateral dimension of the prosthesis 1 ), a height L3 of the prosthesis 1.

[0049] On the other hand, the bone parameter comprises at least one of: a position of a dome D of said prosthesis 1 , an orientation of a joint surface defined by the prosthesis 1 , a type of the prosthesis 1 .

[0050] In more detail, the position of a dome D means a position of at least one prominent structure of the prosthesis 1 (e.g. a point on the prosthesis where its overall height is at its maximum) identified, for example, as a function of a distance of this dome D from a geometric centre of the prosthesis 1 or a minimum or maximum distance from a perimeter edge thereof, in particular a medial perimeter edge thereof.

[0051] Orientation of the articular surface means a position or inclination of the dome D of the prosthesis 1 configured to engage the distal end of the femur also measured with respect to its distance from a perimeter of the prosthesis 1 itself and / or with respect to a main extension plane of the prosthesis 1 .

[0052] In other words, the dome D can be positioned more medially or laterally by modifying the way the patellar tracking development of the femoral component is engaged. In other words, the position of the dome D can be shifted to improve its sliding on the front part of the femoral component as a function of its patellar tracking.

[0053] The type of prosthesis 1 is intended to identify the overall profile of the prosthesis 1 , some possible examples of which are illustrated in Figure 3. Operationally, the method described here thus involves taking a series of measurements on the 3D image of the knee joint, in particular the patella, identifying on it the parameters that define the prosthesis 1 best corresponding to the specific anatomy of the patient mainly considering the structure of the patella and potentially also the structure and characteristics of the adjacent tissues. For example, by measuring the size of the cuts to be made on the patella, it is possible to obtain the engagement parameter by defining the measurements of at least one of the prosthesis length L1 , width L2 and height L3 that best replicates the portion of the patella removed with these cuts.

[0054] Advantageously, the possibility to select the height value L3 and, consequently, to precisely identify the prosthesis 1 that best replicates it is of particular importance since its correct selection preserves a minimum thickness of the patella after the resection operation, guaranteeing its proper functioning and structural stability.

[0055] By way of example, the height L3 can have a minimum value comprised between 12 mm and 15 mm. By way of example, the dimension L3 size vary between 6 and 12mm to ensure a minimum residual patellar bone thickness after the resection operation of 12 / 15mm.

[0056] Still by way of example, with regard to the other dimensional values of the prosthesis, one can consider length L1 values comprised between 26 mm and 38 mm and width L2 values that vary between 30 mm and 42 mm.

[0057] Similarly, by measuring, for example, the shape and orientation of the structures of the removed portion, the corresponding bone parameters can be determined and defined.

[0058] Once the identifying parameters of interest have been acquired, a special database is queried containing prosthetic data identifying a plurality of patellar prostheses 1 that have been catalogued and categorised according to the aforementioned identifying parameters.

[0059] In particular, the patellar prostheses 1 are stored and subdivided within the database into a number of distinct families.

[0060] The families are constituted in such a way that each patellar prosthesis 1 has at least one engagement parameter that is identical to that of every other patellar prosthesis 1 in the same family (preferably all the engagement parameters are identical within the same family) and at least one bone parameter that is different from a corresponding bone parameter of at least one other patellar prosthesis 1 in the same family.

[0061] Thus, overall, each family is defined by all the patellar prostheses 1 adapted to be applied to a specific cut profile (i.e. interfaced with a patella on which cuts with specific dimensional characteristics have been made) and contains within it a plurality of patellar prostheses 1 characterised by structures adapted to replicate respective bone structures of different shapes.

[0062] According to the query just described, the specific patellar prosthesis 1 with the greatest number of matches between the identifying parameters measured on the 3D femur and the identifying parameters of the patellar prosthesis 1 is selected within the database.

[0063] The expression “greatest number of matches” is intended to identify the patellar prosthesis 1 that best approximates the greatest number of identifying parameters of the patient’s patella.

[0064] Advantageously, it is also possible to associate each identifying parameter (engagement or bone) with a relative weight representative of its level of relevance, and the selection of patellar prosthesis 1 is also performed according to this relative weight.

[0065] Preferably, it is also possible to acquire at least one biometric parameter of the patient, and the selection of patellar prosthesis 1 can also be made on the basis of this biometric parameter possibly weighed on the basis of a specific relative weight.

[0066] In particular, the biometric parameter may comprise a morphotype and / or a phenotype of the patient.

[0067] Advantageously, it is also possible to edit or update the database by storing or modifying prosthetic data.

[0068] This can also be performed depending on the outcome of the patellar prosthesis 1 selection step in order to optimise and improve this process. For instance, if the selected patellar prosthesis 1 is not sufficiently satisfactory from the point of view of adaptability to the patient’s anatomy, it is possible to change the relative weight of the parameters and / or modify the prosthesis identification data and re-run the database query to find a more suitable patellar prosthesis 1 for the planned bone repair operation.

[0069] Once the patellar prosthesis 1 has been selected, it is also possible to query a tracking table within which patellar prosthesis 1 tracking data are stored identifying the presence and preferably the position of the selected patellar prosthesis 1 within a storage warehouse.

[0070] In other words, the method involves identifying a specific prosthesis 1 by also identifying the position where this prosthesis 1 is located.

[0071] This allows for easier acquisition and possibly even automation of the process of transferring it from the warehouse to the facility where the bone reconstruction operation will be performed.

[0072] Advantageously, if it is not possible to identify a patellar prosthesis 1 sufficiently compliant and corresponding to the acquired identifying parameters (or if the selected patellar prosthesis 1 is not present in the storage warehouse), an alert signal can be generated.

[0073] For example, such a signal may be generated when the database does not include any prosthetic data identifying a patellar prosthesis 1 with at least one identifying parameter corresponding to the identifying parameters measured on the 3D femur.

[0074] It should be noted that the match is preferably a numerical match and a confidence threshold can be set to determine when there is a match or not between the analysed values.

[0075] For example, a value may be considered a match if it is included in a range centred on the reference value and extending from -5% to +5% of that reference value, preferably if it is included in a range extending from - 3% to +3% of that reference value.

[0076] For example, considering an engagement parameter corresponding to a width L2 of the prosthesis against a measurement on the 3D image of 35 mm, all prostheses 1 with a width L2 comprised between 33.25 mm and 36.5 mm can be considered as conforming to this measurement.

[0077] Alternatively, a value that does not deviate by more than 1 .5 mm from the reference value in terms of dimensional parameters can be considered compliant.

[0078] With regard to a bone parameter identifying a type of prosthesis 1 , it is possible to assign specific values / codes / number references to each type with neighbouring or adjacent values for types of prosthesis 1 with analogous or similar profiles.

[0079] In this context, a level of conformity can also be defined in which prostheses 1 with parameters that are closer to the specific value measured on the 3D image have a higher level of conformity than prostheses 1 which, although still within the indicated range of acceptability, are still further away from the reference value.

[0080] In the case of complete equivalence between several prostheses 1 (even after considering the number of parameters found to be compliant, the relative weight of each parameter and their level of compliance), it is also possible to provide the indication and selection of all prostheses 1 considered to be adequately compliant with the patient’s anatomy so that a user can then select the one most suitable for the specific implementation scenario.

[0081] To further optimise the selection of the most suitable patellar prosthesis 1 , the present method can also be performed in such a way that the 3D model is displayed on a video terminal, superimposing on it a graphic representation of the selected patellar prosthesis 1 .

[0082] On the video terminal, it is then possible to highlight any non-conforming identifying parameters between the 3D model and the graphic representation of the selected patellar prosthesis 1 .

[0083] In this way, it is possible to check whether the selection of the relative weights of the various identifying parameters is satisfactory or whether modifications need to be made in order to select a different patellar prosthesis 1 that better approximates different structural conformations of the bone.

[0084] The method can also be used to store a result of the patellar prosthesis 1 selection step by populating a special results database.

[0085] In other words, data from specific patellar prostheses 1 selected in successive iterations of the method are stored in the results database.

[0086] A statistical analysis determining a selection incidence curve of patellar prosthesis 1 according to its identifying parameters can then be applied to this results database.

[0087] Therefore, it is possible to generate a curve representing the statistical use of the patellar prostheses 1 as a function of their structural and dimensional characteristics.

[0088] This information can be used to optimise the management of families of patellar prosthesis 1 by reducing the number or even eliminating the prostheses 1 that, over time, have not been selected or have been selected a statistically insignificant number of times, while increasing the number of patellar prostheses 1 whose use is more frequent.

[0089] This optimises the possibility of always having a specific prosthesis 1 available that fits the patient’s anatomy for a specific need for an arthroplasty operation.

[0090] It is also possible to use this information for the subsequent design of new prostheses 1 by populating the most frequently used families of prostheses 1 with a greater number of different specimens, creating new prostheses 1 with identifying parameters included in the values of the most frequently used specimens.

[0091] If, for example, there is high use of prostheses 1 belonging to adjacent families, i.e. having values of engagement parameters immediately following one another, it is possible to develop a new family with intermediate engagement parameters between those of the two most frequently used families, thus improving the precision with which the prostheses 1 can be selected.

[0092] The method described so far thus makes it possible to identify and select the patellar prosthesis 1 that best meets the patient’s needs thanks to an optimised approach in which the available prostheses 1 are categorised according to objective criteria that can be quickly and efficiently selected, identified and possibly even modified, providing useful feedback for stock management and the design of new femoral prostheses 1 .

[0093] In accordance with a possible implementation scope, one or more steps of the method described herein can be executed / implemented by an artificial intelligence algorithm.

[0094] In particular, this algorithm can be trained in a supervised manner by providing as input a plurality of images of patellas and / or prostheses 1 labelled with one or more identifying parameters and examples of correspondences between certain sets of identifying parameters and respective prostheses 1 or families of prostheses 1 .

[0095] This training enables the algorithm to identify parameters particularly precisely and accurately when it receives the 3D model as input, as well as to query the database more quickly to identify the best prosthesis 1 to select.

[0096] This application also concerns a system for knee arthroplasty comprising a plurality of families of prostheses 1 for the reconstruction of a patella.

[0097] As can be seen in Figure 2, these prostheses 1 essentially comprise a main body 2 and a plurality of feet 3.

[0098] The main body 2 is configured to slidably engage a femoral component of the knee joint.

[0099] In other words, the main body defines the outer surface of the prosthesis 1 and helps to replicate, together with the distal end of the femur, the joint coupling between the patella and femur.

[0100] The feet 3 extend away from the main body 2 and are permanently fixed to respective seats made in the patella.

[0101] In other words, the fees 3 extend from the main body 2 and allow it to be constrained to the patella.

[0102] Advantageously, the feet 3 can be moved in a main extension plane of the main body 2 to be aligned with the above-mentioned seats.

[0103] In other words, the main body 2 comprises (in one of its surfaces opposite the one designed to replicate the structure of the patella) a series of sliding guides within which the feet 3 are inserted.

[0104] These feet 3 can then be moved within the sliding guides by changing their relative positioning.

[0105] This provides greater freedom in the resection operation of the patella and in the definition of the seats to which the feet 3 will be constrained, as it is not necessary to make the seats according to a predetermined fixed position of the feet 3.

[0106] In fact, the prostheses 1 presented here make it possible to adapt to the anatomical needs of the patient by making the seats in the least invasive and damaging point for the patella and aligning the feet 3 downstream according to the position in which the seats were made.

[0107] In general, each family of patellar prostheses 1 comprises a respective plurality of patellar prostheses 1 whose structure is defined by at least one engagement parameter and one bone parameter.

[0108] These parameters are the same as those described above, and thus the engagement parameter is representative of a size of a portion of prosthesis 1 adapted to engage the patella depending on one or more cutting lines to be performed on that bone, and the bone parameter is representative of a shape of a portion of patellar prosthesis 1 adapted to engage a femoral component of the knee joint;

[0109] In this context, by analogy with the above, each patellar prosthesis 1 has the same engagement parameter as each other patellar prosthesis 1 in the same family and at least one different bone parameter from a corresponding bone parameter of at least one other patellar prosthesis 1 in the same family.

[0110] In general, the system proposed herein makes it possible to classify patellar prostheses 1 by making them more easily identifiable and providing a wide range of solutions in which the best solution is more easily identified and made immediately available thanks to the presence of a set of different patellar prostheses 1 characterised by different shapes and sizes that are classified according to their respective identifying parameters.

[0111] Advantageously, each prosthesis 1 can be further catalogued, categorised or defined according to a biometric parameter that represents an indication of potential patient phenotypes and / or morphotypes.

[0112] In other words, the biometric parameter identifies the respective prosthesis by defining its adaptability to specific known phenotypes and / or morphotypes.

[0113] Within each family of prostheses 1 there are therefore prostheses 1 specifically adapted to best suit the needs of the patient’s specific morphotype / phenotype.

[0114] This makes it possible to personalise prostheses 1 while avoiding the need to design and produce individual prostheses 1 for each arthroplasty operation.

[0115] The present invention also relates to a database comprising prosthetic data identifying a plurality of patellar prostheses 1 belonging to a system as described in the preceding paragraphs and thus subdivided according to respective identifying parameters.

[0116] In particular, patellar prostheses 1 are divided into a number of distinct families, wherein the prostheses 1 of the same family have the same engagement parameter and at least one different bone parameter.

[0117] This database is also specifically queryable during the execution of the method described above.

[0118] Preferably, the database also comprises a tracking table of the prostheses 1 containing tracking data of a position of the prostheses 1 within a storage warehouse.

[0119] The database may further comprise within it (allocated in an appropriate local or distributed memory unit) a results database suitable for storing each prosthesis 1 selected by performing the selection method presented herein.

[0120] Advantageously, the present invention in all the aspects claimed and described achieves the proposed purposes by overcoming the drawbacks complained of in the prior art by making available to the user a method for selecting femoral prostheses 1 , the system comprising such patellar prostheses 1 and the database enabling the desired patellar prosthesis 1 to be identified within the system by performing the various operations provided by the method.

Claims

CLAIMS1. Computer-executable method for selecting a patellar prosthesis (1 ) comprising the steps of:- acquiring a 3D model of a patient’s knee joint at a pre-operative stage;- measuring in said 3D model a plurality of identifying parameters comprising at least one engagement parameter representative of a size of at least a portion of the patellar prosthesis adapted to engage a patella as a function of one or more cutting lines to be performed on said patella, and at least a bone parameter representative of a size of at least a portion of the prosthesis (1 ) adapted to engage a femoral component of the knee joint;- querying a database comprising prosthetic data identifying a plurality of prostheses (1 ) according to respective identifying parameters, said prostheses (1 ) being subdivided into a plurality of distinct families, wherein each prosthesis (1 ) has the same engagement parameter as each other prosthesis (1 ) of the same family and at least a bone parameter different from a corresponding bone parameter of at least one other prosthesis (1 ) of the same family;- selecting from said database a prosthesis (1 ) with the highest number of matches between the identifying parameters measured on the 3D model and the identifying parameters of said prosthesis (1 ).

2. Method according to claim 1 , wherein the engagement parameter comprises at least one of: a length (L1 ) of the prosthesis (1 ), a width (L2) of the prosthesis (1 ), a height (L3) of the prosthesis (1 ); and wherein said bone parameter comprises at least one of: a position of a dome (D) of said prosthesis (1 ), an orientation of a joint surface defined by said prosthesis (1 ), a type of said prosthesis (1 ).

3. Method according to claim 1 or 2, comprising a step of acquiring at least one biometric parameter of the patient and said step of selecting a prosthesis (1 ) is also performed according to said at least one biometric parameter.

4. Method according to claim 3, wherein the at least one biometric parameter comprises at least one of: a morphotype and a phenotype of the patient.

5. Method according to any one of the preceding claims, comprising a step of associating with each identifying parameter a relative weight representative of a level of relevance of said identifying parameter and said step of selecting a patellar prosthesis (1 ) is also performed as a function of said relative weight.

6. Method according to any one of the preceding claims, comprising a step of editing or updating the database by storing or modifying the prosthetic data.

7. Method according to any one of the preceding claims, further comprising a step of querying a tracking table containing tracking data of a position of the prosthesis (1 ) to verify a presence and preferably a position of the selected prosthesis (1 ) within a storage warehouse.

8. Method according to any one of the preceding claims, further comprising a step of generating an alert signal when the database does not include any prosthetic data identifying a prosthesis (1 ) presenting at least one identifying parameter corresponding to the identifying parameters measured on the 3D model.

9. Method according to any one of the preceding claims, comprising thesteps of:- displaying the 3D model on a video terminal;- superimposing a graphic representation of the selected prosthesis (1 ) on said 3D model;- highlighting on said video terminal any non-conforming identifying parameters between the 3D model and said graphic representation of the selected prosthesis (1 ).

10. Method according to any one of the preceding claims, further comprising the steps of:- storing a result of said prosthesis (1 ) selection step by populating a database of results;- applying a statistical analysis to said database of results by determining a selection incidence curve for said prostheses (1 ) as a function of the respective identifying parameters.

11. A knee arthroplasty system comprising a plurality of families of prostheses (1 ) for the reconstruction of at least one component of a knee joint, wherein each family of prostheses (1 ) comprises a respective plurality of patellar prostheses (1 ), and wherein a structure of each prosthesis (1 ) is defined by at least one engagement parameter representative of a size of a portion of the patellar prosthesis adapted to engage a patella as a function of one or more cutting lines to be performed on said patella, and at least a bone parameter representative of a shape of a portion of the prosthesis (1 ) adapted to engage a femoral component of the knee joint; each prosthesis (1 ) having the same engagement parameter as each other prosthesis (1 ) of the same family and at least a bone parameter different from a corresponding bone parameter of at least one other prosthesis (1 ) of the same family.

12. System according to claim 11 , wherein the engagement parameter comprises at least one of: a length (L1 ) of the prosthesis (1 ), a width (L2) of the prosthesis (1 ), a height (L3) of the prosthesis (1 ); and wherein said bone parameter comprises at least one of: a position of a dome (D) of said prosthesis (1 ), an orientation of a joint surface defined by the prosthesis (1 ), a type of the prosthesis (1 ).

13. System according to claim 11 or 12, wherein each prosthesis (1 ) comprises:- a main body (2) configured to slidably engage a femoral component of the knee joint;- a plurality of feet (3) extending away from the main body (2) and stably constrainable to respective seats made in the patella, said feet (3) being movable in a main extension plane of the main body (2) to be aligned to said seats.

14. System according to any one of claims 11 or 13, wherein each prosthesis (1 ) is also categorised according to a biometric parameter identifying potential patient morphotypes and / or phenotypes.

15. Database comprising prosthetic data identifying a plurality of patellar prostheses (1 ) according to respective identifying parameters comprising at least one engagement parameter representative of a size of a portion of the prosthesis (1 ) adapted to engage a patella according to one or more cutting lines to be performed on said patella and at least one bone parameter representative of a shape of a portion of the prosthesis (1 ) adapted to engage a femoral component of the knee joint; said prostheses (1 ) being divided into a number of distinct families, wherein the prostheses (1 ) of the same family have the same engagement parameter and at least one different bone parameter.

16. Database according to claim 15, comprising a tracking table of said prostheses (1 ) containing tracking data of a position of the prostheses (1 ) within a storage warehouse.

17. Database according to claim 15 or 16, comprising a results database adapted to store each prosthesis (1 ) selected by performing said selection method.

18. Database according to any one of claims 15 to 17, wherein said database is queryable during execution of a method for selecting prostheses (1 ) according to any one of claims 1 to 10 and / or said database is configured to store prosthetic data identifying a plurality of prostheses (1 ) belonging to a system according to any one of claims 11 to

Images