Patent Application
20220273465
The present invention relates to a spacer device added with antibiotics for the control of ailments or infections, for example a spacer device for the knee, hip, elbow, shoulder or ankle.
Many joint spacers have been proposed, which are usually made of bone cement.
As it is known, these spacers are used to treat infections occurring after a prosthesis has been grafted, so they are often added with antibiotics.
However, sometimes the infection, even in the presence of spacers, is not treated or is treated very slowly and it is difficult to verify whether this occurs or not, if not when the spacer is removed or if the patient suffers from ailments or pain.
Moreover, in particular with reference to knee and hip spacers, patients sometimes report pain, which can often be attributed to incorrect positioning of the spacer or incorrect preparation of the implant site of the spacer, problems that can be detected only upon patient reporting.
An object of the present invention is to provide a new spacer device.
Another object of the present invention is to provide a spacer device which allows to detect useful parameters regarding the implant site or the spacer itself as soon as implanted.
Another object of the present invention is to provide a spacer device that makes it possible to detect the permanence or healing of an infection and the possible course of the same.
Another object of the present invention is to provide a spacer device capable of performing a diagnostic activity.
Another object of the present invention is to provide a spacer device that allows to detect an incorrect positioning of the spacer or an incorrect preparation of the implant site thereof.
Another object of the present invention is to provide a spacer device that allows to detect the permanence or healing of an infection, incorrect positioning of the spacer or incorrect preparation of the implant site in a simple, quick and reliable way.
Another object of the present invention is to provide a spacer device as indicated above which does not involve risks for the health of a patient,
Another object of the present invention is to provide a new unit for detecting patient parameters or ailments.
In accordance with an aspect of the invention, a spacer device according to the present application is provided.
The present application refers to preferred and advantageous embodiments of the invention,
Other features and advantages of the invention will be more evident from the description of an embodiment of a spacer device and a unit, illustrated by way of example in the accompanying drawings in which:
In the accompanying drawings, identical parts or components are identified by the same reference numbers.
With reference to the attached figures, a spacer device 1 according to the present invention has been illustrated which is intended to be temporarily implanted at a patient's joint area for the replacement of a joint prosthesis, for example infected or extracted from an infected area, for preservation of the dimensions or spaces of the patient's joint area before the implantation of a new prosthesis, in particular after the treatment of the infected area.
A spacer device according to the present invention can for example be a knee, hip, shoulder, ankle or elbow spacer added with antibiotics.
The spacer device 1 comprises at least a sensor 2, 3 as well as electronic means 4 for obtaining and, if desired, transmitting the data detected by the sensor 2, 3, which electronic means 4 are clearly in electrical/electronic communication with the sensor(s) 2, 3.
The sensors or transducers 2, 3 can be of a mechanical, electromechanical, electronic, electrochemical, biochemical or bioelectronic nature. Thus, for example, a mechanical sensor could be used as a temperature detector, if desired including a thermocouple formed by the junction of two metal wires (R, S, B, J, T, E, K, N, C and A types) or of the type electromechanical as an electronic semiconductor resistance thermometer, a transistor or of the electrochemical type, such as liquid crystals.
The electronic means 4 can perform the functions of patient data detection, processing, storage, transmission and reception.
If desired, the electronic means 4 comprise wireless data transmission components.
The expression electronic means 4 means both an optional board 4a or the like, if desired for wireless transmitting, and the electrical connection wires 4b between the board 4a and the sensors 2, 3.
Moreover, detection means of a possible infection in the spacer device 1 or in the implanting area of the same can be provided in the spacer, which detection means comprise at least one temperature sensor 2.
In this regard, an infection always causes an increase in the local temperature.
As it will be understood, the temperature is a very important parameter in particular at night, when there is no friction due to movement and the temperature detected by the sensor is only a function of the possible inflammation given by the infection.
Thanks to this expedient, a forecast of the presence of inflammation is obtained before removing the spacer, so that it is possible to understand whether the inflammation is being treated or not.
Moreover, as a function of this, a spacer device according to the present invention would be able to perform a diagnostic activity, since it can actually help the doctor to diagnose the progress or development of the effectiveness of the spacer in eliminating or reducing an infection.
In essence, the temperature sensor 2 completes and integrates the action of a spacer device 1, since the latter is inserted to maintain the joint spaces and to heal an ongoing infection by releasing locally antibiotics and a temperature sensor as indicated above makes it possible to monitor if the infection is still present.
Furthermore, the status or possible evolution, improvement or worsening of the infection could also be evaluated according to the temperature, since clearly if a temperature decrease is detected over time, it means that the infection is healing, even if the temperature has not fallen yet below a threshold value indicating the absence of infection.
The temperature sensor 2 can be very small in size, for example with a width of about 2-5 mm.
The temperature sensor 2 can comprise a resistance thermometer or a semiconductor or a thermocouple, for example of type K.
If the spacer is a knee spacer device, it can comprise a tibial part 5 (see in particular
Such a spacer could be obtained, for example, as described in European patent EP 1274374B1.
Thus for example the tibial part 5 has a first upper, in use, articulation surface 6a substantially curved or with a ramp delimiting a substantially concave sliding seat, while the femoral part 50 is provided with a first lower, in use, articulation face 60a substantially convex and intended to be positioned in the sliding seat for the sliding engagement of the first upper articulation surface 6a, so as to allow articulation, if desired a mutual angular or roto-translational movement between the tibial part 5 and the femoral part 50, and in turn, once the device is implanted, between the tibia and the femur.
The tibial part 5 can be substantially C-shaped.
The first articulation surface 6a can have, from one side SI to the other S2, a raised intermediate part 5a, as well as two lowered lateral parts 5b, 5c placed one opposite to the other with respect to the intermediate part 5a. For this purpose, the tibial part 5 can be equipped with an intermediate section with a greater thickness, as well as two lateral sections with a lesser thickness placed one opposite the other with respect to the intermediate section.
In this case, a temperature sensor 2 and the electronic means 4 can be provided at any point of the tibial part 5, for example in an intermediate part of the same, if desired in the raised intermediate part 5a. In this regard, as it will be understood, infections develop in the bone interface.
As it is known, the femoral part 50 can instead comprise two condylar sections 50a, 50b, in which case the temperature sensor 2 preferably comprises at least a first temperature sensor 2 in a condylar section 50a and at least a second temperature sensor 2 in the other condylar section 50b.
More specifically, the femoral part 50 can be substantially C-shaped with a base section 50c and two prongs extending from the latter and each defining a respective condylar section 50a, 50b.
The tibial. part 5 and/or the femoral part 50 may or may not be made in one piece.
Moreover, the femoral part 50 can comprise a substantially curved plate shaped body with convexity, in use, facing the tibial part 5.
The first articulation face 60a can have a central hollow band, in use destined to slidingly engage the raised intermediate part 5a of the tibial part, as well as two enlarged lateral bands placed one opposite to the other with respect to the hollow band and each one intended to engage slidingly a respective lowered lateral part 5b, 5c.
In this case, a temperature sensor 2 and the electronic means 4 can be provided at any point of the femoral part 50, for example the electronic means 4 or a respective board 4a in an intermediate part thereof with at least two temperature sensors 2 each in position proximal to a respective side of the spacer device, for example each in a respective condylar section 50a, 50b, at a free end of the base or of an intermediate portion of such condylar section 50a, 50b.
Still with reference to the optional presence of a temperature sensor as a means of detecting an infection, the spacer device can be a hip spacer device (see in particular
Such a femoral component 8 can be, for example, as described in the Italian patent IT1278853.
In this regard, this femoral component 8 can have, for example, a head 8a, if desired hemispherically-shaped constrained, connected to or in one piece with a stem 8b, if desired with the interposition of a connecting neck section 8c. Clearly, the head 8a would be arranged to be disposed, in use, within an acetabular cup, while the stem 8b would be inserted into a patient's femur.
The connecting section 8c can end in an enlarged or flanged section 8d from which the stern 8b extends.
The femoral component 8 may or may not be made in one piece.
If desired, the femoral component 8 can also have a core 8e, if desired metallic, for example rod-shaped, which extends internally from the head 8a to the stem 8b.
In this case, a temperature sensor 2 can be provided at the head 8a designed to evaluate the acetabular temperature and/or a temperature sensor 2 at the stem 8b, designed to detect the temperature of the femoral diaphysis.
These sensors 2 as well as the transmission means 4 can be constrained, if desired by means of a specific adhesive or adhesion means, to the core 8e, if provided.
As regards instead the acetabular cup component 80, it can comprise, as is known, a cap element 80a, if desired semi-spherical, defining a concavity, which cap element 8a can have for example an open annular end 80b which is flared. Moreover, the acetabular cup component 80 can also include one or more ribs 80c, if desired lying on lines passing through the vertex of the cap element 8a, which ribs 80c clearly extend from an internal surface or in any case distal from the femoral component 8.
One or more sensors 2 (three in the example in the figures) can be provided at the vertex of the cap element 80a.
The acetabular cup component 80 may or may not be made in one piece.
With reference instead to an elbow spacer device comprising a humeral stem component and an ulnar stem component, a temperature sensor in the humeral stem component and/or a temperature sensor in the ulnar stem component could instead be provided.
Such a spacer could be, for example, as described in the international application public shed under number WO2016063155A1.
If then the spacer device was a shoulder spacer device, then a temperature sensor could be in a stem component designed to be inserted into a patient's humerus and/or a temperature sensor would be in the head component designed to be articulated with the glenoid cavity of the patient's shoulder blade.
Such a spacer can be, for example, as described in the international application published under number WO2016063146A1.
In accordance with the present invention, the sensor can comprise also or only east one force or load sensor 3.
Such sensor can be for example a strain gauge, which if compressed changes resistance or voltage, a load cell, a piezoelectric ceramic or a transducer or a load sensor of another type.
A load sensor can be present in particular in a knee spacer device or in a hip spacer device.
The force sensor can be important for evaluating, for example, the forces applied to the spacer during walking by a patient in which the spacer is installed.
Thanks to a load sensor 3 or better to more load sensors, a spacer device according to the present invention would be able to carry out a diagnostic activity, because it can actually help the doctor to diagnose the effectiveness of the spacer for maintaining the joint space and the articulation, since if the forces applied to the spacer during walking are excessive or unbalanced, it means that the spacer is improperly implanted and thus that its effectiveness cannot be satisfactory.
With reference to the knee spacer device (see in particular
Preferably, at least two load sensors 3 are provided arranged one at one side of the spacer 1 and the other at the other side, so that the sensors 3 make it possible to evaluate any misalignments between the femoral part 50 and the tibial part 5. The two load sensors 3 are in this case advantageously arranged in a symmetric position with respect to each other with reference to a symmetry plane, in use, sagittal.
If desired, a load sensor 3 is provided in a lowered side part 5b and a load sensor 3 in the other lowered side part 5c.
More specifically, the load sensors 3 are provided at an intermediate area of the lowered. side parts 5b, 5c, i.e. an area where, during the use of the spacer, contact or load applied by the femoral part is always guaranteed. In this case, the intermediate zone in which the load sensor is provided in each lowered lateral part 5b, 5c is intermediate both with reference to a front-back or anteroposterior direction, and from one side to the other or side-medial.
In this regard, considering that each lowered lateral part 5b, 5c defines a respective curved portion of the first upper articulation surface 6a with the concavity facing upwards, the positioning area of the sensors 3 is preferably that relating to the apex of the concavity or in any case to the area at the lower level of the concavity.
The load sensor 3 in the tibial part clearly guarantees a more reliable detection of the force applied on the knee, certainly more reliable than the femoral part, because in the case of the tibial part a contact and thus a load by the femoral part is always.
According to a less preferred variant, the load sensor is in the femoral part 50, for example in the base section 50c or in an intermediate portion.
If, on the other hand, the spacer device is a hip spacer device, then the load sensor 3 is preferably provided at the resting point on the diaphyseal bone, thus substantially at the point of unloading on the femur. With reference to the non limiting embodiment shown in the figures, the load sensor is applied or provided at the connecting section 8c or better of the enlarged or flanged section 8d.
In this regard, if one put the sensor in the head of this device, contact or anyway correct detection of the load may not always be guaranteed, because when the spacer head is rotated a precise point of transferring the forces cannot would not be present. The presence of the sensor at the point of resting on the diaphyseal bone instead always guarantees the detection of the force applied on the hip.
The sensor in a device according to the present invention could also be a biochemical type sensor, for example for pH or for other parameters.
The sensor could then also include another type of sensor, if desired a sensor sensitive to biohumoral parameters such as monoclonal antibodies suitable for the supersensitive identification of bacterial presence and a bioosmotic sensor confined in the spacer device and, for example separated from the biological environment by means of a semipermeable membrane, if desired sensitive to specific ions released from any pathological process.
Moreover, the sensor could also include at least an accelerometer, designed to measure and/or detect the acceleration or movements of the spacer device and therefore of a patient in which it is implanted, for example during walking or physiotherapy sessions.
Thus, the accelerometer would collect a patient's displacement data and then allow the transmission or acquisition of the same when necessary or expected.
As it will be understood, the data collected by the accelerometer, in particular in combination with those collected by another sensor, in particular a temperature sensor, would make it possible to understand whether in the event of a parameter change, for example in the case of an increase in temperature of the spacer device, this is due to the movement of the patient and therefore of the spacer device itself or, in the absence of movement, to the onset or persistence of an infection.
A device according to the present invention comprises a main body, for example made of polymethylmethacrylate, in which case the sensor 2, 3 and the electronic means 4 are embedded in the main body, so that the sensor 2, 3 and the electronic means 4 are in a position impermeable to biological fluids of a patient.
In essence, the sensor 2, 3 as well as the electronic means 4 can be in a hermetic zone, so that these components do not come into contact with a patient's biological fluids.
A sensor 2, 3 and more particularly a load or force sensor could be encapsulated or protected in whole or in part by a sort of button component or housing 7.
This button component or housing 7, in particular in the case of a knee spacer device, moves by a very small or infinitesimal entity as a result of the force or load applied to it.
Such a button component or housing 7 could be made of any suitable material, such as for example polyethylene, ceramic or other.
According to this variant, in particular in the case of a knee spacer device, the latter delimits one or more through holes TH or in any case opening in the area of detection by means of the sensor 3, for example at the first upper articulation surface 6a, in which, in use, the push-button component or housing 7 is housed or emerges and is engageable from the outside of the spacer.
In accordance with the non-limiting embodiment shown in the figures, the spacer device 1 delimits two through holes TH one opening into a lowered side part 5b and one into another lowered part 5c, and two pressure sensors are then provided and two respective push-button components or housings 7 arranged or in any case emerging each at a respective through hole TH.
Alternatively, no button component or housing 7 could be provided, in which case the sensor 3 would be embedded in the material of the spacer device, under a layer of the same, in which case the deformation of the material, for example polymethylmethacrylate, of the device spacer would press the underlying sensor 3. In this case, the layer of the material of the spacer device above or covering the sensor could be between 0.1 and 5 mm, or between 0.1 and 3 mm.
A small gap can be delimited between the material layer of the device and the sensor.
With particular reference to a knee spacer 1, if desired to a tibial part 5 of the same, it could comprise two half-shells 5d, 5e designed to define between them a positioning zone of the sensor(s) 2, 3 and of the electronic means 4.
More specifically, a first half-shell 5d could delimit, on the one hand, the first upper articulation surface 6a and, on the other, a recessed area IZ defining inside it one or more recesses R,
The second half-shell 5e could instead define on one side a constraint or resting surface 6b on a tibia or on a component to be constrained to a tibia and on the other of the projecting parts 9 for the engagement with the recesses R.
Clearly, there could be recesses in the second half-shell 5b and protruding parts in the first half-shell 5d or an intermediate solution among those now described.
In this case, the button component(s) or housing(s) 7 and the components of the electronic means 4 and possibly the sensors 2, 3 could be housed in the recesses R of the first 5d and/or of the second 5b half shell.
The two half-shells 5d, 5b could then be constrained to each other with any suitable means, such as bone cement, glues, adhesives or interlocking means or mechanical engagement.
Similar considerations can be made for the femoral part 50.
Clearly, only recesses could be provided in one of t half-shells in which the sensors 2, 3 and the electronic means 4 would be housed.
Advantageously, the device does not include energy sources for activating sensor 2, 3 and electronic means 4, therefore there would be a passive electronic circuit. In this case, there would be no electrical risk due to the breakdown of any battery, or short circuits or possible leakage of chemical components from the latter.
A spacer device 1 according to the present invention can be made of biologically compatible material.
This biologically compatible material can be chosen among metals, metal alloys, organo-metal compounds.
Alternatively, the biologically compatible material can be chosen from the ceramics, the high porosity resins, the plastic materials and/or a combination thereof.
Specifically, the aforementioned plastic materials can be selected from thermoplastic polymers, such as acrylic resins, polyethylene, polypropylene, polyester, thermoformable polymers and the like.
In a preferred version of the present invention, the biologically compatible material is a bone cement, for example polymethylmethacrylate (PMMA).
The presence of an internal core, for example metal, is particularly useful especially when the spacer device 1 is made of plastic or ceramic material.
In this way, it is possible to confer a better stability to the system, a high resistance to loads, etc.
In a version of the invention, the spacer device 1 is made of PMMA or internal core is metallic and covered with PMMA.
The aforementioned biologically compatible material, thanks to its porosity, can be impregnated with pharmaceutical and/or therapeutic products, such as for example antibiotics, before its use, by the manufacturer and/or doctor before implantation.
In accordance with the present invention, a unit 10 for detecting parameters or ailments of a patient is also provided comprising a device 1 as well as a group or component for receiving and processing 11 of the data received from the sensor(s) 2, 3, which is or can be placed in electronic communication with electronic means 4.
The group for receiving and processing 11 can include an electrical power supply component of the sensor(s) 2, 3 and/or of the electronic means 4, which power supply component is separate or not integrated in the spacer device 1.
The power supply component can be integrated into a garment 12 wearable by a user, such as an elastic band or an underwear.
The group for receiving and processing 11 further comprises receiving means, such as a scanner or reader, of the data transmitted by the electronic means 4, if desired also the receiving means being integrated into the garment 12.
This group for receiving and processing 11 can then be equipped with an activation means or switch.
In essence, according to this variant, when the group for receiving and processing 11 is approached to the spacer device 1 and this group is activated, if activation is provided, the data(s) is obtained from the sensor(s), but when the group for receiving and processing 11 is moved away or switched off, then the aforementioned data(s) are no longer obtained
The elastic band or the underwear 12 can for example comprise, as a power supply component, a built-in coil designed to induce an electric current for supplying sensor 2, 3 and electronic means 4, through the skin and tissues.
The group for receiving and processing 11 can then be provided with a control component 13 designed to receive and process the data obtained from the sensors 2, 3.
The elastic hand or the underwear 12 can then comprise a data transmission system, WIFI or by cable, of the data obtained from the sensor 2, 3 to the control component 13 of the group for receiving and processing 11 for their processing.
As an alternative to what now indicated, the group for receiving and processing 11 could include a scanner or reader designed to read or receive data from the transmission means, but not a power supply component. In such a case, clearly, the spacer device 1 could include a small battery or even two or more batteries.
The control component 13 can include a computer, such as a PC, a tablet, a smartphone or other, in electronic communication with the other members of the group or component for receiving and processing 11 and responsible for processing the data received and carrying out the appropriate evaluations, for example regarding the presence or absence of the infection or the status of the infection (thanks to the temperature sensor), an excessive or unbalanced load (thanks to the load sensor) or other.
The control component 13 can be integrated in a housing of the group 11 or can be remote from it and in electronic communication, for example by cable or even wireless, with the other elements of the group.
The data collected and processed by group 11 could then be transmitted, for example, to a doctor, if desired also to the doctor's mobile phone for the appropriate evaluations.
If the device is also equipped with at least an accelerometer, then the reader would also read the data detected by the accelerometer and the control component 13, which is arranged to receive and process the data obtained from the sensors 2, 3 of the device, thanks to the data obtained from the accelerometer, could evaluate the movements of the spacer device and therefore of the patient according to the data detected by the other sensors of the device.
With regard to this, as indicated above, the data detected by the accelerometer, for example in combination with those detected by a temperature sensor, would make it possible to understand if in the event of an increase in the temperature of the spacer device, this is attributable to the patient's movement and in turn of the spacer device itself or, in the absence of movement, at the onset or persistence of an infection.
If a plurality of sensors are provided in the spacer device, in particular a plurality of load sensors, the same would be identified, i.e. they would have an individual number and the control component 13 would know the position of the sensors so as to be able to perform the appropriate assessments in a targeted or weighted manner on the actual position of any excessive temperature, or above all excessive or too low load or pressure. The group or component for receiving and processing 11 or the respective control component 13 therefore has means for identifying and recognizing the sensors 2, 3.
The computer can be equipped with specific software for data processing.
Thus, for example, the software could be designed to perform a statistical evaluation, if desired on surveys carried out several times a day, or every one, two, three or more days.
In this case, with reference in particular to the temperature sensor, on the basis of the finding now proposed, it would be possible, for example, to assess whether the temperature remains high or decreases over time, so as to establish in substance whether or not the infection is healing. This could be done by storing in the control component 13 or it could be associated with a data storage component where suitable values or specifications or diagrams are stored.
Therefore, the control component 13 could have a data storage space for saving the results of the processing carried out.
It is reiterated that the position of the sensor(s) is also important for assessing where an excessive load, an extremely low a load and/or an infection occurs.
As it will be ascertained, thanks to a spacer device according to the present invention it is possible to detect, useful parameters regarding the implant site or the spacer itself when implanted.
Moreover, if a temperature sensor operating as indicated above is provided, it is possible to detect the permanence or healing of an infection and the possible course of the same.
A load sensor would instead allow to ascertain an incorrect positioning of the spacer or an incorrect preparation of the implant site of the same, even in the absence of symptoms detected by the patient.
In essence, thanks to the presence of one or more sensors, in particular a temperature or load sensor 3, a spacer device according to the present invention is capable of performing a diagnostic activity, since it actually can help a doctor to diagnose the progress or development of the spacer's effectiveness for reducing or eliminating an infection or for maintaining joint space.
Moreover, in particular if the spacer device does not include energy sources for the activation of the sensor(s) 2, 3 and of the electronic means 4 there would be no electrical risk due to the breaking of a possible battery, or short circuits o possible leakage of chemical components from the latter, and thus no risk of compromising the health of a patient where the spacer device is implanted would occur.
Modifications and variations of the invention are possible within the scope of protection defined by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102019000012372 | Jul 2019 | IT | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2020/056752 | 7/17/2020 | WO |
