Patent Application
20210346162
The present invention relates to a joint prosthesis component adapted to be fixed to a first bone extremity of a joint of a single patient, in particular a first bone extremity having compromised anatomy.
The invention also relates to a surgical instrumentation for preparing the bone for the implant of the joint prosthesis component and a related method for manufacturing said component.
The invention finds useful application in the field of joint prostheses adapted to be implanted in patients with particularly compromised joint anatomy, for instance in case of prosthetic revision, and in particular in case of coxal anchor of hip prosthesis and ulnar component of elbow prosthesis.
The following description is made with non-limiting reference to the latter prosthetic components, even though this does not prevent from applying the invention to other components of hip or knee prosthesis or of other joint prostheses.
As it is well known in this technical field, under particular pathological conditions of the joints it is recommended to intervene with the implant of a prosthesis. In particular, an arthroplasty surgery is indicated in case of serious damage to the joint surfaces due for instance to degenerative diseases such as rheumatoid arthritis and arthrosis or to fractures.
In order to pursue a successful prosthetic implant, the design of the prosthetic components, the surgical instruments used for the implant and the surgical technique must be aimed at pursuing a suitable primary and secondary stability and, on the one hand, at restoring the best possible biomechanical condition.
In particular, in order to ensure a suitable stability of the implant, it is advisable to maximize the filling of the existing bone defects and the bone-implant contact surface, so as to ensure a stable and long-lasting fastening and a suitable transfer of the loads as uniformly and anatomically as possible, all this by means of a surgical technique that is the least invasive possible.
The technical solutions nowadays adopted substantially provide for the alternative use of two types of joint prostheses: prostheses with standard components and prostheses customized based on the anatomy of the single patient.
Though advantageous under various aspects, and substantially fulfilling the purpose, both the standard prostheses and the customized prostheses do not allow obtaining a suitable stability and/or a correct joint biomechanics in patients with a particularly compromised joint anatomy, namely in the presence of a marked reabsorption of bone tissue, deformation and/or fracturing. This anatomic condition may in particular occur in patients who need a joint prosthesis revision surgery.
In particular, the joint prostheses of the standard type provide a finite number of prosthetic components and surgical instruments having predefined shapes and size. Therefore, the surgeon must choose the components and instruments that best suit the case. However, often the operator does not have the needed instruments and/or components and must find a compromise. As a skilled person is well aware of, in case of particularly altered joint bone anatomies, it is very complicated to find an optimal compromise among the available elements and components. One often finds himself in the condition of having to remove too much or too little bone tissue to try to match and stabilize one of the standard components to the bone, however having to accept a non-optimal positioning in the space of the component or a non-optimal biomechanical recovery, or to pursue the suitable positioning in the space of the component, accepting to lose in implant stability. Therefore, this approach ensures an optimal success of the implant only in patients having a joint anatomy which little differs from the physiological condition.
An alternative solution used in patients having compromised anatomy is described for example in patent application No. WO 2015/187038 A1 which relates to the use of a prosthesis which may be defined of the customized type. In other words, prosthetic components are customized in the design step, so that, once implanted, they perfectly match with the bone anatomy of the single patient. This solution was conceived to avoid the need of removing bone tissue to adapt with the implant in order to obtain an optimal contact area with the bone and restoration of biomechanical parameters, since it is the implant itself that already has a morphology matching with the bone anatomy of the single patient.
However, though advantageous under various aspects and substantially fulfilling the purpose, in case of particularly compromised anatomies this solution has some drawbacks. In particular, not always is it possible to design a prosthetic component such as to fill all defects of the bone tissue, to suitably adhere to the bone and to be positioned so as to ensure an optimal joint biomechanics.
Finally, a customized prosthetic component often needs the use of a surgical technique that is different, potentially more invasive, than those commonly used by surgeons to implant components of the standard type. In some extreme cases the customized prosthetic component would need a so complex and invasive surgical procedure that it cannot be performed, or the component would significantly lose its anatomical filling feature to be inserted into the anatomy.
The object of the present invention is to provide a joint prosthetic component adapted to be fixed to the compromised anatomy of a single patient, having structural and functional features such as to overcome the above drawbacks with respect to the prior art and to maximize the chances of success of the implant, thus ensuring optimal primary and secondary stability and joint biomechanics for each patient.
The solution idea underlying the present invention is to conceive a joint prosthesis component capable of customization with respect to the compromised anatomy of the corresponding joint bone extremity of a single patient, such as to match with the suitably processed bone in order to obtain an optimal fixing and positioning of the prosthetic component.
Based on this solution idea, the previously identified technical problem is solved by a joint prosthesis component according to claim 1.
Specific embodiments of the joint prosthesis component are defined in the dependent claims.
The above joint prosthesis component is designed so as to optimize the morphology of the component itself in connection with a processing of the bone extremity which is predefined to contribute obtaining a successful implant for each patient with compromised joint anatomy.
The above component is customized for each single compromised anatomy of a patient in order to have a morphology defined based on a specific processing of the bone anatomy to maximize the bone-implant contact by filling the bone defects and obtain a suitable stability of the implant, meanwhile positioning the prosthetic component in such a way as to ensure an optimal biomechanics of the prostheses, all this implantable through a surgical technique as less invasive as possible.
In other words, conversely to the known prosthetic components, the positioning of the component and restore of the biomechanical parameters are not conditioned by the availability of finished prosthetic components or by the need of pursuing the anatomy or stability of the implant, the morphology of the component may be advantageously defined along with the optimal bone processing, so as to obtain a suitable positioning and stability of the implant for each patient with compromised anatomy.
The above processing may be advantageously performed with at least one surgical instrument, which may be in turn advantageously customized to make the specific processing aimed at preparing the bone to receive the corresponding component.
Furthermore, advantageously, the prosthesis component may provide for at least one porous trabecular three-dimensional structure and/or at least one suture hole to increase the integration of the implant with the bone and surrounding soft tissues.
Advantageously, the porous trabecular structure may be in turn customized for instance in terms of shape, positioning in the component, thickness, porosity, trabecular structure to adapt to the possibly processed compromised bone anatomy of the single patient. Furthermore, the positioning and size of the suture holes in the joint prosthesis component may also be customized according to the bone anatomy.
For instance, the suture holes may advantageously be formed at the porous three-dimensional structure in order to obtain in a determined area of the implant a synergic effect in promoting the integration with the surrounding tissues.
The joint prosthesis component may be a coxal anchor of a hip prosthesis in which the customized portion is represented by a distal surface of an acetabular support which adapts to the morphology of the acetabular cavity of the patient with a specifically processed compromised anatomy.
The coxal anchor may also comprise additional components to the acetabular support, which may be flanges, stems, wedges, thicknesses or inserts, that can be fixed to one or more of the anatomical portions that delimit the acetabular cavity—ileum, pubis and ischium—by cementing and/or by means of fixing screws.
The additional support provided by the additional components also allows fixing the coxal anchor to anatomical sites of smaller size with respect to the acetabular cavity, thus increasing the implant stability.
As previously mentioned, these additional components may advantageously be customized, so as to be shaped to the corresponding bone portion, also possibly processed by means of at least one surgical instrument, which in turn may advantageously be customized to perform the processing aimed at preparing the bone to receive the corresponding component.
The additional components may be integral with the acetabular support or with the latter in the implant step by cement interposition.
Alternatively, the coxal anchor may provide for a plurality of additional components, for instance flanges, having different size and/or morphological features, among which the surgeon may choose the most suitable ones to be used.
The joint prosthesis component may be an ulnar component of elbow prosthesis.
Said ulnar component may comprise a proximal fastening portion adapted to be fixed to a proximal epiphysis of the ulna of a patient with compromised anatomy and a distal fastening portion adapted to be fixed within a diaphysis of said ulna, wherein at least one of said proximal and distal fastening portions has a specific shape with respect to the morphology of a proximal portion of the ulna specifically processed by means of at least one surgical instrument.
The above identified technical problem is also solved by a surgical instrument for processing a first bone extremity of a patient with compromised anatomy aimed at implanting a joint prosthesis component according to what has been previously discussed, at least partially specifically shaped to process the first bone extremity so as to adapt to the customized surface of the joint prosthesis component.
Said surgical instrumentation may advantageously provide for at least one customized portion specifically shaped to process the bone so as to perfectly adapt to the joint prosthesis component. For instance, said customized processing portion may be specifically shaped to process the acetabular cavity of the coxal bone and/or ileum and/or pubis and/or ischium, so as to match with the distal surface of the acetabular support or with a corresponding additional component, respectively.
The above identified technical problem is also solved by a manufacturing method for manufacturing a joint prosthesis component adapted to be fixed to a first bone extremity of a joint of a single patient having compromised anatomy, comprising the steps of:
The above manufacturing method may also provide for an optimization step of the processing of the first bone extremity and of the customization of the customized contact surface in the joint prosthesis component.
As a skilled person may well understand, the optimization of the bone processing and of the component morphology may advantageously be performed upstream of the surgery in order to identify the best possible combination of the two variables in connection with the compromised anatomy of the single patient.
The above manufacturing method may further include the step of providing at least one surgical instrumentation having at least one customized portion specifically shaped so as to perform the processing of the first bone extremity that adapts to the customized surface of the joint prosthesis component.
The features and advantages of the joint prosthesis component, of the instrumentation and of the manufacturing method according to the present invention will become apparent from the following description, of more than one possible exemplifying embodiment, given by way of non-limiting example with reference to the appended drawings.
The present invention relates to a joint prosthesis component 10, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, adapted to be fixed to a first bone extremity 50, 150, 250, 350, 450, 550, 650, 750, 850, 950, 1050 of a joint of a single patient, in particular a first bone extremity having compromised anatomy. “Single patient” obviously means a single and customized use of the prosthesis component.
The above component comprises at least one joint portion 4, 904 adapted to be directly coupled with a second bone extremity or with a conjugate second joint prosthesis component, in turn fixed to the second bone extremity.
The joint prosthesis component comprises at least one bone fastening portion 12, 102, 202, 302, 402, 502, 602, 702, 802, 902, in which at least one contact surface 13, 103, 203, 303, 403, 503, 603, 703, 803, 903 is defined, which is adapted to be directly in contact with the first bone extremity 50, 150, 250, 350, 450, 550, 650, 750, 850, 950, 1050, 1150.
Said contact surface advantageously has a morphology such as to perfectly match with the first bone extremity 50, 150, 250, 350, 450, 550, 650, 750, 850, 950, 1050, 1150 which has been subjected to a specific processing, for instance a bone tissue removal, by means of at least one surgical instrumentation 2000.
This processing may advantageously be performed by means of at least one surgical instrumentation having at least one customized processing portion to perform the desired specific processing. Obviously, this does not exclude that in some cases the processing may be performed by means of instruments having standard size and shape.
As it will become apparent from the examples which will be hereinafter discussed, a prosthetic component of this type may be designed considering two variables such as component morphology and bone processing, so as to conceive a prosthetic component which may obtain optimal stability and biomechanics of the prosthesis once implanted.
This solution may be an advantageous alternative to the solutions known in the field, namely to the use of standard or completely customized joint prostheses, in particular in case of a particularly compromised joint bone anatomy.
Hereinafter, with reference to the appended figures, examples of components of joint prosthesis according to the invention, namely of coxal anchor of hip prosthesis 10, 100, 200, 300, 400, 500, 600, 700, 800 and ulnar component of elbow prosthesis 900, 1000, 1100, will de deepened without any limiting purpose.
With reference to
With reference to
In
The coxal anchor 10 of
As it can be noticed from
Analogously to the acetabular support 12, the additional supports 15, 16 are customized to adhere to the respective bone element which has been subjected to the previously discussed processing with reference to
As a skilled person may well understand, the coxal anchor 10 of
In the particular case of a coxal anchor, the biomechanics of the prothesis is affected by the positioning of the joint rotation center located at the distal surface of the acromial support and of the orientation in the space of the above distal surface which is defined by the so-called “covering” and “version” of the acetabular support. A suitable position of the rotation center, covering and version, which not necessarily coincide with the anatomic ones, may thus be chosen and optimized in the design step by acting on two variables such as bone processing and prosthesis design.
In other words, unlike the known prosthetic components, the positioning of the component is not conditioned by the need of pursuing implant stability, the morphology of the component may advantageously be defined along with the optimal bone processing, so as to have a suitable positioning and stability of the implant for each patient having compromised anatomy.
The design of the coxal anchor 50 and processing discussed in connection to
As it can be noticed, the coxal anchor 100 as well has an iliac support 106 and a pubic support 105, both customized so as to adapt to the respective specifically processed bone element.
As a skilled person may well understand, the additional supports 15, 16, 105, 106 used in the coxal anchors 50, 100 of
Beside the two above discussed examples, alternative embodiments of the coxal anchor may provide for one or more pubic supports and/or one or more iliac supports and/or one or more ischial supports according to the basic bone anatomy and to the defined processing.
In addition to the flange shape, these pubic, iliac and ischial supports may take up other appearances; for instance, they may be real projections, extensions or appendices of the distal surface of the acromial support which occupy bone gaps extending within the pubis, ileum or ischium.
The above discussed traditional supports may be made integral with the acetabular support or fixed to the latter in the implantation step by means of cement or other fasteners.
Furthermore, these additional supports may be customized analogously to the acromial supports 12, 102, so as to match with the specifically processed and not processed pubis, ileum or ischium, or be components having standard shape and size adapted to the anatomy.
The stem 406 shown in
Alternative embodiments may further provide for a plurality of iliac stems having for instance a different morphology, like in the case of the coxal anchor 500 of
Furthermore, the use of a stem to fix the coxal anchor to other bone elements different from ileum is not excluded.
Other three examples of coxal anchor 600, 700, 800 are shown in
As a skilled person may notice from the figures relating to the above discussed examples of coxal anchor 10, 100, 200, 300, 400, 500, 600, 700, 800, the coxal anchor may at least partially comprise a three-dimensional structure at least partially trabecular porous adapted to be in contact with the bone, thus favouring the primary fixing and integration with the bone. A structure of this type allows the passage of body fluids and reduces bacterial colonization risks of the implant surfaces. In the figures so far cited said trabecular portions are indicated with reference TS.
As it may be noticed for instance from
As a skilled person may well understand, the use of a trabecular portion and suture holes produce a synergic effect in favouring the integration of the prosthetic implant with the surrounding tissues.
With reference to the example of the previously discussed joint prosthetic component, we hereinafter report a table in which a coxal anchor made according to the invention is compared with the two types of prothesis known nowadays.
The above reported table shows a range 1-10 in which 10 is the best for each evaluation parameter of an implant goodness. From the table a skilled person may immediately appreciate how a coxal anchor made according to the invention allows achieving an excellent result in all the evaluated parameters, namely optimizing for instance both positioning, fitting and stability of the implant.
With reference to
As it will be immediately apparent to a skilled person, the ulnar components hereinafter discussed are usable in a total knee prosthesis of the hinged type. This type of elbow prothesis provides for an ulnar component fixed to the proximal end of the ulna and a humeral component fixed to the distal end of the homer, which are hinged to each other thus allowing the rotation about a pin.
This obviously does not exclude for an ulnar component of other types of knee protheses—for instance not hinged or partial ones—or other components of knee prostheses to be made according to the invention.
In
Said ulnar component 900 comprises in turn a joint portion 904 adapted to be hinged to a corresponding portion of a humeral component of knee prothesis and a bone fastening portion 902 in which a contact surface 903 is defined, which is adapted to be in contact with the bone when the component is implanted as shown in
The above fastening portion 902 has an under-fastening proximal portion 902′ and a distal under-fastening portion 902″. The proximal 902′ and distal 902″ fastening portions are advantageously shaped to adapt to the morphology of the proximal epiphysis 951 and of the diaphysis 952 which are specifically processed by means of at least one surgical instrumentation 2000.
As it may be noticed in
Furthermore, in alternative embodiments just one of the two portions 902′, 902″ may be customized in connection to a particular processing of the bone and the other one may be customized to the not processed or standard bone anatomy.
Analogously to what has been discussed in the previous examples of joint prosthesis component, the ulnar component 900 as well is designed considering two variables such as component morphology and bone processing, so as to conceive a prosthetic component which can produce optimal stability and biomechanics of the prothesis once implanted.
As it will be clearer hereinafter, the discussed ulnar components allow minimizing the bone to be removed, gaining stability and integration of the implant to the bone and to the soft tissues and obtaining a correct joint movement.
The processing of the ulna 950 may advantageously be performed by means of a customized instrumentation, in order to obtain the desired processing.
Obviously this does not exclude for the bone to be processed by means of standard instruments.
As it is clear from
Even in this case the suture holes 3 and the trabecular portion TS perform a synergic action in ensuring a suitable integration and stability of the implant.
Like the morphology of the component, the number and position of the suture holes 3 and trabecular portions TS may also be customized according to the bone anatomy of the patient and to the chosen bone processing.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102018000009413 | Oct 2018 | IT | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/077439 | 10/10/2019 | WO | 00 |
