WO2021139915A1

WO2021139915A1 - Orthopedic implant with diaphyseal and/or metaphyseal filling

Info

Publication number: WO2021139915A1
Application number: PCT/EP2020/081640
Authority: WO
Inventors: Giorgio BURASTERO
Original assignee: Adler Ortho S.P.A.
Priority date: 2020-01-09
Filing date: 2020-11-10
Publication date: 2021-07-15
Also published as: IT202000000196A1

Abstract

An orthopedic implant with diaphyseal and/or metaphyseal filling (1, 1', 1", 1"') is disclosed, particularly for the prosthetization of a knee of a patient, which comprises an (i) implant body (2) adapted to be fixed to a knee prosthesis and to the femur or tibia of the patient, (ii) a prosthesis coupling portion (3) configured to be fixed to the knee prosthesis, and (iii) a bone coupling portion (4) configured to be fixed to the femur or tibia; the bone coupling portion (4) is provided with an additive powder technology.

Description

ORTHOPEDIC IMPLANT WITH DIAPHYSEAL AND/OR METAPHYSEAL FILLING

The present invention relates to an orthopedic implant with diaphyseal and/or metaphyseal filling, useful in particular in the field of the prosthetization of the knee of a patient.

As is known, in orthopedics, the expression “implantation of an articular prosthesis” or “prosthetization” is understood to refer to the replacement of a joint with a structure that is similar but artificially originated and known as articular prosthesis.

The present invention is applied specifically in the prosthetization of the knee and in particular in prosthetic revision or revision prosthetization, i.e., in the replacement of one or more prosthetic components. There are many causes that can make this procedure necessary, some linked to the wear of the implant due to time and use, others linked to specific complications. The common goal, regardless of the motivation that has provided an indication for revision, is to restore to the patient a properly functioning joint.

As is known, in revision knee prosthesis replacement surgery there is often a bone loss in the proximal tibia and/or in the distal femur, i.e., in the portions of the tibia and femur that are closest to the knee joint.

In order to obviate this bone loss, prosthetic elements known as filling implants have been developed which have the function of compensating for said bone loss by replacing in practice the missing bone tissue in the proximal tibia and/or in the distal femur.

These filling implants can be diaphyseal (adapted to be arranged at the diaphysis of the bone) and/or metaphyseal (adapted to be arranged at the metaphysis of the bone); in the case of implants that are both diaphyseal and metaphyseal (therefore adapted to be arranged at the metaphysis and at the diaphysis of the bone) one speaks of "metadiaphyseal" implants. Hereinafter, for the sake of simplicity, any implant that can be diaphyseal or metaphyseal or metadiaphyseal will be termed "diaphyseal and/or metaphyseal filling implant" .

These diaphyseal and/or metaphyseal filling implants are made of biocompatible material, such as titanium, and usually have a substantially cylindrical or frustum-like or fork-like shape and comprise a prosthesis coupling portion configured to be fixed to one or more components of the knee prosthesis and a bone coupling portion configured to be fixed to the femur or the tibia.

In greater detail, metaphyseal and/or diaphyseal filling implants known as "sleeves" are known which can be both tibial and femoral and in which the connection to the prosthesis is provided mechanically by means of a Morse taper.

Metaphyseal and/or diaphyseal filling implants known as "tapers" are also known which can also be tibial and femoral and in which the connection to the prosthesis is provided by means of cement.

These orthopedic implants with metaphyseal and/or diaphyseal filling of the known type, while being useful and practical, have some aspects that can be improved which are linked to the capacity for osteointegration in the tibia or in the femur, to strength, to ease of manufacture and of application.

In particular, a better osteointegration would improve the strength and reliability of the entire prosthesis.

The aim of the present invention is to overcome the limitations of the background art described above, providing an orthopedic implant with diaphyseal and/or metaphyseal filling that has a high osteointegration capacity.

Within this aim, an object of the present invention is to provide an orthopedic implant with diaphyseal and/or metaphyseal filling that has high strength and reliability.

A further object of the invention is to provide an orthopedic implant with diaphyseal and/or metaphyseal filling that is easy to provide and economically competitive if compared with the background art.

A further object of the invention is to provide an alternative to the background art.

This aim, these objects and others which will become more apparent hereinafter are achieved by an orthopedic implant with diaphyseal and/or metaphyseal filling, particularly for the prosthetization of a knee of a patient, which comprises an implant body adapted to be fixed to a knee prosthesis and to the femur or tibia of the patient and comprising a prosthesis coupling portion configured to be fixed to said knee prosthesis and a bone coupling portion configured to be fixed to said femur or tibia, characterized in that said bone coupling portion is provided with an additive powder technology.

This aim and these and other objects are also achieved by a method according to claim 7. Further characteristics and advantages will become more apparent from the description of some preferred but not exclusive embodiments of an orthopedic implant with diaphyseal and/or metaphyseal filling, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1A is a lateral elevation view of a first embodiment of an orthopedic filling implant, according to the invention;

Figure IB is a sectional view, taken along a vertical plane, of the orthopedic filling implant of Figure 1A;

Figure 2 A is a lateral elevation view of a second embodiment of an orthopedic filling implant, according to the invention; Figure 2B is a sectional view, taken along a vertical plane, of the orthopedic filling implant of Figure 2A;

Figure 3 A is a lateral elevation view of a third embodiment of an orthopedic filling implant, according to the invention;

Figure 3B is a sectional view, taken along a vertical plane, of the orthopedic filling implant of Figure 3 A; Figures 4A and 4B are two lateral elevation views, taken from two different viewpoints, of a fourth embodiment of an orthopedic filling implant, according to the invention.

With reference to the figures, the orthopedic implant with diaphyseal and/or metaphyseal filling is generally designated by the reference numeral 1 optionally followed by one or more prime symbols to indicate the various embodiments. The orthopedic filling implant is diaphyseal and/or metaphyseal in that it can be diaphyseal (adapted to be placed at the diaphysis of the bone) or metaphyseal (adapted to be placed at the metaphysis of the bone) or both diaphyseal and metaphyseal (i.e., metadiaphyseal) and therefore, in this last case, adapted to be arranged at the metaphysis and at the diaphysis of the bone. As already mentioned, in the present description and in the accompanying claims, the expression “implant with diaphyseal and/or metaphyseal filling” is understood therefore to indicate an implant which can be diaphyseal or metaphyseal or metadiaphyseal.

The implant is intended in particular for the prosthetization of a knee of a patient and comprises an implant body 2 adapted to be fixed to a knee prosthesis and to the femur or tibia of the patient.

In greater detail, the implant body 2 comprises a portion for coupling to the prosthesis 3 configured to be fixed to the knee prosthesis (i.e., at least to one component thereof) and a bone coupling portion 4 configured to be fixed to the femur or to the tibia (depending on the embodiments), i.e., to be arranged in contact with the bone tissue so as to osteointegrate with it.

In particular, the bone coupling portion 4 comprises at least part of the external surface of the implant body 2 that is inserted in the bone (tibia or femur) so as to facilitate its osteointegration.

In other words, the bone coupling portion 4 comprises at least the interface surface that, in the anatomical condition for use (when the implant is implanted in the patient), is in contact with the bone tissue of the tibia or of the femur.

The prosthesis coupling portion 3 can comprise for example an end of the implant body 2, or a protrusion (such as preferably a Morse taper 31), or a coupling seat or cavity, depending on the constructive requirements and the surgical choices.

In some embodiments, for example the one shown in Figures 1A and IB, the orthopedic filling implant 1 is diaphyseal, femoral and of the “sleeve” type.

In some embodiments (not shown), the orthopedic filling implant is diaphyseal, femoral and of the “taper” type.

In some embodiments (not shown), the orthopedic filling implant is diaphyseal, tibial and of the “sleeve” type.

In some embodiments (not shown), the orthopedic filling implant is diaphyseal, tibial and of the “taper” type.

In some embodiments, for example the one shown in Figures 3 A and 3B, the orthopedic filling implant 1” is metadiaphyseal (i.e., metaphyseal and diaphyseal), femoral and of the “sleeve” type.

In some embodiments, for example the one shown in Figures 2 A and 2B, the orthopedic filling implant is metadiaphyseal (metaphyseal and diaphyseal), femoral and of the “taper” type.

In some embodiments (not shown), the orthopedic filling implant is metaphyseal, tibial and of the “sleeve” type.

In some embodiments, for example the one shown in Figures 4 A and 4B, the orthopedic filling implant ” is metaphyseal, tibial and of the “taper” type.

In some embodiments (not shown), the orthopedic filling implant is metaphyseal, femoral and of the “sleeve” type.

In some embodiments (not shown), the orthopedic filling implant is metaphyseal, femoral and of the “taper” type.

In some embodiments (not shown), the orthopedic filling implant is metadiaphyseal, tibial and of the “sleeve” type.

In some embodiments (not shown), the orthopedic filling implant is metadiaphyseal, tibial and of the “taper” type.

As shown for example in Figures 2 A and 3 A, in the embodiments in which the orthopedic implant is metadiaphyseal (metaphyseal and diaphyseal), the implant body 2 comprises a metaphyseal portion 21 (adapted to be fixed at the metaphysis of the bone) and a diaphyseal portion 22 (adapted to be fixed at the diaphysis of the bone); in this case, the bone coupling portion 4 is formed in practice by the outer wall of the metaphyseal portion 21 and the diaphyseal portion 22 of the implant body 2.

In some of the embodiments in which the orthopedic filling implant 1 , 1” is of the “sleeve” type, the prosthesis coupling portion 3 comprises a Morse taper 31 (i.e., a conical element for coupling by means of the known “Morse taper” conical coupling method, which uses a system for the connection of two metal parts having a male and a female conical shape) and a fixing thread 32.

Preferably, the implant body 2 is extended along a longitudinal axis Y and the bone coupling portion 4 comprises an external surface 41 that at least partly diverges with respect to said longitudinal axis Y.

Even more preferably, the bone coupling portion 4 comprises a fork shaped portion of the implant body 2.

In the preferred embodiments, the orthopedic filling implant 1 comprises a coupling cavity 50 adapted to be engaged by a prosthetic element in a known manner.

According to the invention, the bone coupling portion 4 is provided by means of an additive powder technology, so that the bone coupling portion 4 is porous, so as to facilitate its osteointegration.

Preferably, the bone coupling portion 4 is made of titanium and/or titanium alloy powder, i.e., by using a titanium powder and/or a titanium alloy powder as additive material. In the preferred embodiments, the additive powder technology comprises one of the following methods:

- sintering of the metal by electron beam melting, also known as “EBM”;

- laser sintering, such as for example selective laser melting, also known as “SLM”, or selective laser sintering, also known as “SLS”

Advantageously, the bone coupling portion 4 thus provided is porous, comprising a plurality of pores which facilitate osteointegration.

Preferably, the bone coupling portion 4 is provided by means of an additive powder technology so as to comprise pores having a size (width) comprised between 300 and 1000 microns. The Applicant has in fact found that this porosity, and in particular this pore size, increases osteointegration significantly.

The functioning method of the orthopedic implant with diaphyseal and/or metaphyseal filling 1 becomes clear and evident from what has been described.

In particular, for example, for the prosthetization of both the femoral part and of the tibial part, it is possible to use one of the described orthopedic filling implants of the sleeve or taper type.

The choice of the type of filling implant is a function of the surgical technique of the orthopedic surgeon.

The “sleeve” solution allows a precise mechanical coupling by means of the Morse taper 31. The "taper" solution requires the use of cement, which is not welcomed by all doctors, but allows degrees of freedom which are sometimes indispensable for correct tissue balancing.

This last solution allows the use of any revision prosthesis that is commercially available.

In practice it has been found that the orthopedic implant with diaphyseal and/or metaphyseal filling according to the present invention achieves the intended aim and objects, since it has a high osteointegration capacity.

Another advantage of the orthopedic implant with diaphyseal and/or metaphyseal filling, according to the invention, resides in the fact that is is very strong and reliable. A further advantage of the orthopedic implant with diaphyseal and/or metaphyseal filling according to the invention resides in the fact that it is easy to provide and economically competitive if compared with the background art.

Another advantage of the orthopedic implant with diaphyseal and/or metaphyseal filling according to the invention resides in the fact that it provides an alternative to the background art.

The orthopedic implant with diaphyseal and/or metaphyseal filling thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the accompanying claims. All the details may furthermore be replaced with other technically equivalent elements.

In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art. The disclosures in Italian Patent Application No. 102020000000196 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. An orthopedic implant with diaphyseal and/or metaphyseal filling (1, V, 1”, G”), particularly for the prosthetization of a knee of a patient, which comprises an implant body (2) adapted to be fixed to a knee prosthesis and to the femur or tibia of the patient and comprising a prosthesis coupling portion (3) configured to be fixed to said knee prosthesis and a bone coupling portion (4) configured to be fixed to said femur or tibia, characterized in that said bone coupling portion (4) is provided with an additive powder technology.

2. The orthopedic implant with diaphyseal and/or metaphyseal filling (1, G, 1”, G”) according to claim 1, characterized in that said bone coupling portion (4) is made of titanium and/or titanium alloy powder.

3. The orthopedic implant with diaphyseal and/or metaphyseal filling (1, L, 1”, G”) according to claim 1 or 2, characterized in that said additive powder technology comprises a method from:

- sintering of the metal by electron beam melting;

- laser sintering.

4. The orthopedic implant with diaphyseal and/or metaphyseal filling

(1, G, 1”, G”) according to one or more of the preceding claims, characterized in that said prosthesis coupling portion (3) comprises a Morse taper (31) and a fixing thread (32).

5. The orthopedic implant with diaphyseal and/or metaphyseal filling

(1, G, 1”, G”) according to one or more of the preceding claims, characterized in that said implant body (2) is extended along a longitudinal axis (Y); said bone coupling portion (4) comprises an external surface (41) that at least partially diverges with respect to said longitudinal axis (Y).

6. The orthopedic implant with diaphyseal and/or metaphyseal filling

(1, G, 1”, G”) according to one or more of the preceding claims, characterized in that said bone coupling portion (4) is porous and comprises pores having a size comprised between 300 and 1000 microns.

7. A method for providing an orthopedic implant with diaphyseal and/or metaphyseal filling (1, G, 1”, G”), particularly for prosthetization of a knee of a patient, comprising an implant body (2) adapted to be fixed to a knee prosthesis and to the femur or tibia of the patient and comprising a prosthesis coupling portion (3) configured to be fixed to said knee prosthesis and a bone coupling portion (4) configured to be fixed to said femur or tibia, characterized in that said bone coupling portion is provided with an additive powder technology.

8. The method according to claim 7, characterized in that said bone coupling portion (4) is made of titanium and/or titanium alloy powder.

9. The method according to claim 7 or 8, characterized in that said additive powder technology comprises a method chosen from: - sintering of the metal by electron beam melting;

- laser sintering.

10. The method according to one or more of claims 7 to 9, characterized in that the bone coupling portion (4) is provided with said additive powder technology so as to comprise pores having a size comprised between 300 and 1000 microns.