US20180235514A1 - System and method for determining patient follow-up subsequent to an orthopaedic procedure - Google Patents

Abstract

A method of determining patient follow-up subsequent to an orthopaedic procedure includes determining the number of cycles of use of an orthopaedic joint of the patient. If a predetermined threshold is exceeded, communication with an orthopaedic care provider is initiated. A patient monitoring system is also disclosed.

Description

CROSS-REFERENCE TO RELATED U.S. PATENT APPLICATION
• This application is a continuation application of U.S. patent application Ser. No. 14/736,802, now U.S. Pat. No. 9,949,669, which is a continuation application of U.S. patent application Ser. No. 14/223,393, now U.S. Pat. No. 9,055,918, filed Mar. 24, 2014, which is a divisional application of U.S. patent application Ser. No. 13/300,535, now U.S. Pat. No. 8,702,799, which was filed on Nov. 18, 2011 and is a continuation application of U.S. application Ser. No. 11/024,888 entitled “SYSTEM AND METHOD FOR DETERMINING PATIENT FOLLOW-UP SUBSEQUENT TO AN ORTHOPAEDIC PROCEDURE” by Mark D. DiSilvestro et al., which was filed on Dec. 29, 2004, the entirety of which is hereby incorporated by reference.
FIELD OF DISCLOSURE
• The present disclosure relates generally to systems and methods for use in conjunction with orthopaedic procedures.
BACKGROUND
• Currently, patient follow-up subsequent to an orthopaedic procedure is a function of the time that has elapsed since the procedure. Indeed, follow-up meetings with the orthopaedic care provider (e.g., the surgeon) are typically scheduled for dates in the future which reflect the passage of a given amount of time since the procedure.
SUMMARY
• According to one aspect, a system for monitoring a patient's use of an orthopaedic joint which includes first and second joint prosthesis components includes an implantable sensor, a processor, and a memory device. The implantable sensor, when implanted in a patient, can be used to monitor the number of cycles of use of the orthopaedic joint. The processor in communication with the sensor. The memory device is electrically coupled to the processor and has stored therein a plurality of instructions which, when executed by the processor, cause the processor to (i) monitor output from the sensor to determine the number of cycles of use of the orthopaedic joint and (ii) to generate a message to the patient indicative of a need to initiate communication with an orthopaedic care provider if the number of cycles of use of the orthopaedic joint exceeds a predetermine threshold value. In some embodiments, the implantable sensor may be embodied as a permanent magnet embedded in the first joint prosthesis component and a Hall effect switch embedded in the second joint prosthesis component. The system may further comprising electronics associated with the permanent magnet and the Hall effect switch that are adapted to determine the number of occasions in which the first and second joint prosthesis component are in a predetermined position relative to one another.
• In some embodiments, the processor and memory device are embedded in one of the first and second joint prostheses. Alternatively, the processor and memory device may be located in a data interpretation device separate from the orthopaedic joint. In such embodiments, the electronics may include a transmitter to transmit data indicative of the number of occasions in which the first and second joint prosthesis component are in the predetermined position relative to one another to the data interpretation device. Additionally or alternatively, the electronics may be configured to determine the number of occasions in which a predetermined angle of flexion is attained by the orthopaedic joint. For example, the predetermined angle of flexion is indicative of a step having been taken by the patient. In some embodiments, the message may be at least one of an audible message and a visual message.
• According to another aspect, a system for determining patient follow-up subsequent to an orthopaedic procedure may include an orthopaedic prosthesis and a computing device. The orthopaedic prosthesis may include a femoral component having a signal source embedded therein and a tibial component having an electrical circuit embedded therein. The electrical circuit may include a sensor to generate a data signal in response to the signal source. Additionally, the electrical circuit may be configured to (i) determine the number of occasions in which the femoral component and the tibial component are in a predetermined position relative to one another as a function of the data signal, (ii) calculate a cycle count indicative of a cumulative number of cycles of use of the orthopaedic prosthesis, and (iii) transmit the cycle count. The computing device may be configured to receive the data signal and generate a message indicating a need to initiate communication with an orthopaedic care provider in response to the cycle count exceeding a reference threshold value.
• In some embodiments, the signal source may be embodied as a permanent magnet and the sensor may be embodied as a Hall effect switch. Additionally or alternatively, the computing device may include a display. In such embodiments, the message comprises a visual message displayed on the display of the computing device. In some embodiments, the computing device may be further configured to initiate a communication with the orthopaedic care provider in response to the cycle count exceeding the reference threshold value. For example, the computing device may be configured to generate an e-mail to the orthopaedic care provider. Additionally or alternatively, the computing device may be configured to initiate a telephone call to an office of the orthopaedic care provider.
• In some embodiments, the computing device may include communication circuitry, a display, a processor, and a memory. The memory may have stored therein a plurality of instructions that, in response to the processor, cause the processor to generate a visual message to the patient on the display that indicates a need to initiate communication with the orthopaedic care provider in response to the cycle count exceeding the reference threshold value and initiate a communication with the orthopaedic care provider in response to the cycle count exceeding the reference threshold value.
• According to a further aspect, a method for determining patient follow-up subsequent to an orthopedic procedure may include generating a data signal with a Hall effect switch embedded in a first joint component of an implanted joint prosthesis in response to a permanent magnet embedded in a second joint component of the implanted joint prosthesis. the method may also include generating a cycle count indicative of the number of occasions in which the first and second joint components are in a pre-determined position relative to one another. Additionally, the method may include transmitting the cycle count to a computing device external to the patient, comparing the cycle count to a reference threshold, and initiating communication with an orthopaedic care provider in response the cycle count having a predetermined relationship with the reference threshold.
• In some embodiments, the method may include generating an e-mail to the orthopaedic care provider and/or initiating a telephone call to an office of the orthopaedic care provider. Additionally, in some embodiments, the method may include generating a message on the computing device indicating a need to initiate communication with the orthopaedic care provider in response to the cycle count having the predetermined relationship with the reference threshold value. The method may also include electronically querying the implanted joint prosthesis with the computing device to obtain the cycle count. Additionally or alternatively, the method may include transmitting the cycle count comprises transmitting the cycle count to the computing device in response to a query received from the computing device.
BRIEF DESCRIPTION OF THE DRAWINGS
• The detailed description particularly refers to the accompanying figures in which:
• FIG. 1 is a diagrammatic view showing a joint use measurement device in the form of a pedometer being utilized to determine the cycles of use of a knee endoprosthesis system;
• FIG. 2 is a diagrammatic view showing a joint use measurement device in the form of a electronic body monitor being utilized to determine the cycles of use of a knee endoprosthesis system;
• FIG. 3 is a diagrammatic view showing a joint use measurement device in the form of an implantable joint cycle counter being utilized to determine the cycles of use of a knee endoprosthesis system; and
• FIG. 4 is a diagrammatic view showing a joint use measurement device in communication with a communication device.
DETAILED DESCRIPTION OF THE DRAWINGS
• The present disclosure relates to a method for determining patient follow-up after an orthopaedic procedure, such as a joint replacement procedure, based on the actual use of the patient's joint. As will be described herein in greater detail, the number of cycles of use of the patient's joint may be determined, for example, by (i) determining number of steps taken by the patient, (ii) determining the activity level of the patient, (iii) determining the number of times a predetermined joint flexion angle is achieved, or (iv) determining the number of loading cycles of the joint. Determination of these parameters may be achieved in a number of different manners. When it is determined that the patient has achieved a level of use in which follow-up is desired, a communication with the orthopaedic care provider (e.g., a surgeon, hospital, nurse, primary care provider, or other individual involved in the care of the patient) is initiated by notifying the patient and/or the orthopaedic care provider. As will be described herein in greater detail, such communication may be achieved in a variety of different manners.
• Referring now toFIG. 1, there is shown one implementation of the concepts of the present disclosure. In this case, a jointuse measurement device10 is utilized to determine the number of cycles of use of a prostheticorthopaedic joint12. In the exemplary arrangement ofFIG. 1, theorthopaedic joint12 is exemplary embodied as aknee endoprosthesis system14 for use in a total knee replacement procedure. Theknee endoprosthesis system14 is implanted on the distal end of thefemur16 and the proximal end of thetibia18. Theendoprosthesis system10 includes a tibial bearing20 that is positioned on the proximaltibial component22. The proximaltibial component22 is affixed to the proximal end of thetibia18. Thetibial bearing20 has a contouredproximal surface24, against which thecondyles26 of the distalfemoral component28 bear. The distalfemoral component28 is affixed to the distal end of thefemur16. Articulation of the joint is at the interface of theproximal surface24 of thetibial bearing20 and thecondyles26 of the distalfemoral component28.
• The actual use of theknee endoprosthesis system14 may be characterized as cycles of use of the system. The cycles of use of thesystem14 may be measured in a variety of methods such as, for example, (i) by determining number of steps taken by the patient, (ii) by determining the activity level of the patient, (iii) by determining the number of times a predetermined joint flexion angle is achieved by thesystem14, or (iv) by determining the number of loading cycles of thesystem14.
• In the exemplary embodiment shown inFIG. 1, the jointuse measurement device10 is embodied as apedometer30. Thepedometer30 is worn by the patient subsequent to the patient's orthopaedic procedure to determine the number of steps taken by the patient. When the output from thepedometer30 indicates that the patient has taken a predetermined number of steps since the patient's orthopaedic procedure (or since the patient's previous meeting with the surgeon), a communication with the orthopaedic surgeon may be initiated. For example, the patient may make an appointment with the surgeon's office via telephone, electronic mail or other web-based communication, conventional mail, etcetera.
• Referring now toFIG. 2, there is shown an arrangement similar toFIG. 1, but showing the jointuse measurement device10 embodied as anelectronic body monitor32. The electronic body monitor32 is configured to be worn externally of the patient's body such as, for example, on an armband. Like thepedometer30 ofFIG. 1, the electronic body monitor32 may be used to determine the number of steps taken by the patient over a given period of time (e.g., since the patient's procedure or since the patient's previous post-surgical meeting with the surgeon). The electronic body monitor32 may also execute algorithms for determining and tracking the activity level of the patient. In this way, follow-up may be initiated as a function of steps taken by the patient, activity level of the patient, or both.
• As shown inFIG. 2, the electronic body monitor32 includes asensor34 that is configured to sense parameters associated with cycles of use of theknee endoprosthesis system14. Thesensor34 may be embodied as a single sensor or as an array of sensors. In one exemplary embodiment, thesensor34 is embodied as a two-axis accelerometer the output from which may be used to determine the number of steps taken by the patient. The electronic body monitor32 also includes aprocessor36 electrically coupled to thesensor34, amemory device38, and adata output port40. Theprocessor36 is electrically coupled to thedata output port40 and thememory device38. The electronic body monitor32 may also include other devices useful in a computing device such as drivers, registers, buffers, digital signal processors, and the like. Illustratively, the electronic body monitor32 may be embodied, with or without modification thereto, as any one of the numerous body monitors commercially available from BodyMedia, Incorporated of Pittsburgh, Pa. One such BodyMedia device is commercially sold under the name SenseWare PRO.
• Theprocessor36 andmemory device38 cooperate to determine when follow-up subsequent to an orthopaedic procedure is warranted based on cycles of use of theknee endoprosthesis system14. In particular, thememory device38 has stored therein a plurality of instructions in the form of a software routine which performs such a function. Thememory device38 may be Random Access Memory (hereinafter sometimes RAM), Read Only Memory (hereinafter sometimes ROM), flash or erasable memory such as Erasable Programmable ROM (hereinafter sometimes EPROM) and Electrically Erasable Programmable ROM (hereinafter sometimes EEPROM), and/or other memory devices. Due to the adaptable nature of programming languages, there are many embodiments of a software routine stored in thememory device38 for performing such a function.
• The electronic body monitor32 also includes amessage generating device42. Themessage generating device42 is operable to generate visual and/or audible messages for presentation to the patient. For example, when the electronic body monitor32 determines that the patient has exceeded a predetermined threshold relating to the number of steps taken by the patient (or activity level) since the patient's procedure (or last meeting with the surgeon), an audible and/or visual alert may be generated by themessage generating device42. Themessage generating device42 may be embodied as any type of such device including, for example, an LCD or LED display and/or a tone/sound generator.
• Referring now toFIG. 3, the jointuse measurement device10 includes an implantedsensor50. Thesensor50 may be embodied as a single sensor or as an array of sensors. In the exemplary embodiment ofFIG. 3, the implantedsensor50 includes asignal source52, such as a permanent magnet, that is embedded in the distalfemoral component28, and asensor54, such as a Hall effect switch, embedded in theproximal tibial component22. The associatedelectronics56 are also secured to theproximal tibial component22. Theelectronics56 include, amongst other things, a processor, memory device, power source, modulator, a transmitter, and antenna to facilitate the maintenance of a running count of the number of times theknee endoprosthesis system14 cycles, along with the ability to transmit such a count from within the patient's body. In other words, the jointuse measurement device10 illustrated inFIG. 3 utilizes an implanted sensor to determine the number of occasions in which the components of theknee endoprosthesis system14 are in a predetermined relative position with one another (e.g., the number of occasions in which a predetermined flexion angle is attained), thereby determining cycles of use of thesystem14.
• The stored count information can be transmitted to a device external to the patient's body by use of the transmitter and antenna of the associatedelectronics56. As shown schematically inFIG. 3, anexternal receiver58 anddata interpretation device60 may be used to retrieve information from the implantedelectronics56. Theexternal receiver58 may be embodied as a radio-frequency antenna that is operable to receive the signal from the internal antenna of the implantedelectronics56. Thedata interpretation device60 is electrically coupled to thereceiver58, and may be embodied as a standard computer (e.g., PC) programmed to demodulate the radio-frequency signal received from the internal transmitter and the internal antenna of the implantedelectronics56. Thedata interpretation device60 may also be embodied as a hand-held personal computer, a personal desk assistant, a laptop computer, or any custom-designed data acquisition device. Thedata interpretation device60 may be programmed to perform calculations necessary to convert the received and demodulated signal into the number of cycles recorded by the counter.
• One such implantable system, along with the associated external components, is disclosed in U.S. patent application Ser. No. 10/887,766, entitled “In Vivo Joint Implant Cycle Counter” which is assigned to the assignee of the present application, and which is hereby incorporated by reference.
• Thedata interpretation device60 may have integrated therein, or be coupled to, amessage generating device62. Themessage generating device62 is operable to generate visual and/or audible messages for presentation to the patient. For example, when it is determined from the output of the implantedelectronics56 that the number of occasions in which theknee endoprosthesis system14 has attained a predetermined flexion angle has exceeded a predetermined threshold, an audible and/or visual alert may be generated by themessage generating device62. Themessage generating device62 may be embodied as any type of such device including, for example, a PC display monitor, an LCD or LED display, and/or a tone/sound generator.
• In lieu of the arrangement ofFIG. 3 which includes a magnet and Hall effect switch, other implanted sensor arrangements are also contemplated. For example, a load sensor may be implanted into theknee endoprosthesis system14. In such a system, the cycles of use of thesystem14 could be determined by counting loading cycles of the system. Such a count could be stored, transmitted, and received in a similar manner to as described above in regard to the arrangement ofFIG. 3.
• In another example, the cycles of use of the patient's joint may be determined by measuring the wear of certain components of theknee endoprosthesis system14. For instance, a sensor arrangement may be utilized in which the joint space between thefemoral component28 and thetibial component22 is measured/monitored. It should be appreciated that such a distance may shorten (i.e., reduce) over cycles of the knee endoprosthesis system as a result of wear of thetibial bearing20. As such, the cycles of use of thesystem14 could be determined by measuring and tracking the joint space between thefemoral component28 and thetibial component22. Such data could be stored, transmitted, and received in a similar manner to as described above in regard to the arrangement ofFIG. 3. One such implantable system, along with the associated external components, is disclosed in U.S. patent application Ser. No. 10/888,243, entitled “System and Method for Determining Patient Follow-Up Subsequent to an Orthopaedic Procedure” which is assigned to the assignee of the present application, and which is hereby incorporated by reference.
• Referring now toFIG. 4, there is shown the jointuse measurement device10 being used in conjunction with acommunications device70. Thecommunications device70 may be embodied as hardware and software that is integrated into a personal computer, wireless (e.g., cellular) telephone, PDA, or home automation system. Alternatively, thecommunications device70 may be a discreet hardware/software assembly electrically coupled to a personal computer, wireless (e.g., cellular) telephone, PDA, or home automation system. In either case, thecommunications device70 includes devices useful in a computing device such as microprocessor(s), memory devices, drivers, registers, buffers, digital signal processors, and the like
• Thecommunications device70 may be operated to query the jointuse measurement device10 and then commence an automated, device-initiated communication with the orthopaedic care provider (e.g., the surgeon's office) if a follow-up visit is warranted based on the number of cycles of use of theknee endoprosthesis system14. For example, thecommunications device70 may initiate a telephone call, electronic mail communication, or other web-based communication with an electronic device orsystem72 operated by the surgeon's office.
• It should be appreciated that thecommunications device70 may be configured to accommodate any one or more of the different exemplary embodiments of the jointuse measurement device10. For example, in the case of the electronic body monitor32 ofFIG. 2, thecommunications device70 may be configured to communicate with the body monitor32 via itsdata output port40. Such a communication may be wired or wireless depending on the configuration of theport40. It is contemplated to integrate thecommunications device70 into theelectronic body monitor32.
• Similarly, thecommunications device70 may be configured to communicate withdata interpretation device60 of the arrangement ofFIG. 3 via either a wired or wireless communication link. It should be appreciated that thecommunications device70 may be integrated into the data interpretation device60 (i.e., a single device, such as a PC, may be equipped with the necessary hardware and software to perform both the functions of thedata interpretation device60 and the functions of the communications device70).
• In the case of when the jointuse measurement device10 is embodied as a mechanical device (i.e., non-electrical) such as, for example, certain types of pedometers, data from the mechanical device may be input into thecommunications device70. In such a case, thecommunications device70 may be configured to process such manually entered data, and then, if appropriate, initiate communication with the surgeon in any one or more of the manners described above.
• Although the concepts of the present disclosure have herein been described in regard to a knee prosthesis, it should be appreciated that the concepts described herein could also be applied to other joint endoprosthesis such as endoprosthesis systems for use in the hip, shoulder, wrist, elbow, ankle, along with endoprosthesis systems for use with the digits of the extremities. It should be understood that other configurations of a joint use measurement device (including its sensors) may be utilized to accommodate a given application in a desired joint location.
• Moreover, although the concepts of the present disclosure have herein been exemplary described in regard to an endoprosthesis for use in a total joint replacement, it should be appreciated that the concepts described herein could also be applied to other arrangements. For example, the concepts of the present disclosure could be applied subsequent to a procedure in which the resultant joint includes one or more natural components. Moreover, the concepts of the present disclosure could be applied subsequent to an orthopaedic procedure at anatomical locations other than a joint.
• While the disclosure is susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and has herein be described in detail. It should be understood, however, that there is no intent to limit the disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.
• There are a plurality of advantages of the present disclosure arising from the various features of the apparatus and methods described herein. It will be noted that alternative embodiments of the apparatus and methods of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of an apparatus and method that incorporate one or more of the features of the present disclosure and fall within the spirit and scope of the present disclosure.

Claims (14)

1-14. (canceled)

15. An orthopaedic system, comprising:

a femoral component configured to be coupled to a patient's femur,

a tibial component configured to be coupled to a patient's tibia,

a load sensor coupled to the tibial component operable to generate an electrical output signal,

a first electrical circuit coupled to the load sensor, the first electrical circuit being operable to (i) detect electrical output signals generated by the load sensor, (ii) determine a parameter associated with movement of the femoral component relative to the tibial component based on the signals generated by the load sensor, and (iii) wirelessly transmit a signal indicative of the parameter, and

a second electrical circuit operable to (i) wirelessly receive the signal indicative of the parameter, and (ii) provide an assessment of the femoral component and the tibial component based on the parameter.

16. The orthopaedic system ofclaim 15, wherein the parameter associated with movement of the femoral component relative to the tibial component is a number of cycles.

17. The orthopaedic system ofclaim 16, wherein the number of cycles includes a number of loading cycles.

18. The orthopaedic system ofclaim 15, wherein the first electrical circuit and the load sensor are embedded in a single housing.

19. The orthopaedic system ofclaim 18, wherein the first electrical circuit and the load sensor are embedded in the tibial component.

20. The orthopaedic system ofclaim 15, wherein the second electrical circuit includes a visual display configured to provide a visual assessment of the femoral component and the tibial component based on the parameter.

21. An orthopaedic system, comprising:

a tibial component,

a load sensor coupled to the tibial component operable to generate an electrical output signal,

a first electrical circuit coupled to the load sensor, the first electrical circuit being operable to (i) detect electrical output signals generated by the load sensor, (ii) determine a parameter associated with movement of a femoral component relative to the tibial component based on the signals generated by the load sensor, and (iii) wirelessly transmit a signal indicative of the parameter, and

a second electrical circuit operable to (i) wirelessly receive the signal indicative of the parameter, and (ii) provide an assessment of the femoral component and the tibial component based on the parameter.

22. The orthopaedic system ofclaim 21, wherein the parameter associated with movement of the femoral component relative to the tibial component is a number of cycles.

23. The orthopaedic system ofclaim 22, wherein the number of cycles includes a number of loading cycles.

24. The orthopaedic prosthesis system ofclaim 23, wherein the first electrical circuit and the load sensor are embedded in a single housing.

25. The orthopaedic system ofclaim 24, wherein the first electrical circuit and the load sensor are embedded in the tibial component.

26. The orthopaedic prosthesis system ofclaim 21, wherein the second electrical circuit includes a visual display configured to provide a visual assessment of the femoral component and the tibial component based on the parameter.

27. A method comprising:

coupling a tibial component and a load sensor to a proximal end of a patient's tibia,

moving a femoral component coupled to a distal end of a patient's femur relative to the tibial component through a number of degrees of flexion, and

monitoring a visual display for an assessment of the femoral component and the tibial component based on a parameter associated with movement of the femoral component relative to the tibial component based on signals generated by the load sensor,

wherein the load sensor is coupled to a first electrical circuit operable to (i) detect signals generated by the load sensor, (ii) determine the parameter associated with movement of the femoral component relative to the tibial component based on the signals generated by the load sensor, and (iii) wirelessly transmit a signal indicative of the parameter to the visual display.

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