Intraoperative joint force measuring device, system and method

• US 7,458,989 B2
• Filed: 06/30/2005
• Issued: 12/02/2008
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Original Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Inventors: Banks, Scott A., Tanino, Hiromasa
• Primary Examiner(s): Snow; Bruce E.
• Assistant Examiner(s): WOLF, MEGAN YARNALL
• Application Number:
  US11/172,556
• Publication Number:
  US 20070005145A1
• Time in Patent Office: 1,251 Days
• Field of Search: 623/22.41, 623/22.45, 623/20.15, 623 2242- 2311, 623/23.39, 623/18.12, 623/22.4, 623/22.11, 623/22.12, 623/23.4, 623/23.42, 606/102
• US Class Current: 623/22.45
• CPC Class Codes: A61B 2050/3008 having multiple compartments
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive
• CPC Class Codes: A61B 50/33 Trays
• CPC Class Codes: A61B 90/06 Measuring instruments not otherwise provided for
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/3609 Femoral heads or necks; Connections of endoprosthetic heads or necks to endoprosthetic femoral shafts A61F2/3601 takes precedence
• CPC Class Codes: A61F 2/3662 Femoral shafts
• CPC Class Codes: A61F 2/4637 for connecting or disconnecting two parts of a prosthesis
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2/468 Testing instruments for artificial joints for testing non-implantable prostheses A61F2/76
• CPC Class Codes: A61F 2/4684 Trial or dummy prostheses
• CPC Class Codes: A61F 2002/3021 frustoconical
• CPC Class Codes: A61F 2002/30299 umbrella-shaped or mushroom-shaped
• CPC Class Codes: A61F 2002/30332 Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30339 Double cones, i.e. connecting element having two conical connections, one at each of its opposite ends
• CPC Class Codes: A61F 2002/30354 Cylindrically-shaped protrusion and recess, e.g. cylinder of circular basis
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30604 : modular
• CPC Class Codes: A61F 2002/30616 : Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/3067 : for data transfer
• CPC Class Codes: A61F 2002/30716 : for single use, e.g. having means for preventing re-use
• CPC Class Codes: A61F 2002/3611 : Heads or epiphyseal parts of femur
• CPC Class Codes: A61F 2002/3625 : Necks
• CPC Class Codes: A61F 2002/365 : Connections of heads to necks
• CPC Class Codes: A61F 2002/4018 : Heads or epiphyseal parts of humerus
• CPC Class Codes: A61F 2002/4632 : using computer-controlled surgery, e.g. robotic surgery
• CPC Class Codes: A61F 2002/4633 : for selection of endoprosthetic joints or for pre-operative planning
• CPC Class Codes: A61F 2002/4641 : for disconnecting
• CPC Class Codes: A61F 2002/4666 : for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2002/4681 : by applying mechanical shocks, e.g. by hammering
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2220/005 : using adhesives
• CPC Class Codes: A61F 2230/0067 : conical
• CPC Class Codes: A61F 2230/0093 : Umbrella-shaped, e.g. mushroom-shaped
• CPC Class Codes: A61F 2250/0002 : for data transfer
• CPC Class Codes: A61F 2250/0064 : Sets comprising a plurality of prosthetic parts of different sizes
• CPC Class Codes: A61F 2250/009 : for single use, e.g. having means for preventing re-use
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures

Abstract

A surgical device for joint replacement surgery includes an intraoperative joint head having a stem attachment structure where the stem attachment structure may be removably attachable to a stem and a force sensor housed by the joint head for measuring in vivo forces during surgery. The in vivo forces may be generated by one or more of tension provided by soft tissue, load application during surgery, limb movement during surgery, and a combination thereof. Also, the joint head may provide a cavity where the stem attachment structure houses the force sensor and may be removably insertable in the joint head cavity. A method of performing joint replacement surgery includes installing an intraoperative joint head having a force sensor housed by the joint head and a stem attachment structure, the stem attachment structure being removably attachable to a stem, measuring joint forces, and adjusting an implant parameter based on the measured joint forces.

Claims

1. A surgical device for joint replacement surgery, comprising:

an intraoperative joint head having a cavity for accepting the insertion of a stem attachment structure;

a stem attachment structure being removably attachable to a stem and removably insertable in the joint head cavity;

a plurality of force sensors disposed within the joint head for measuring in vivo forces during surgery;

wherein the force sensors are placed at the periphery of the joint head cavity and the distance between adjacent force sensors is uniform, and at least one force sensors is located coaxial with a longitudinal axis of the stem such that the plurality of force sensors measure joint component forces to determine the resultant joint vector; and

wherein the in vivo forces are generated from the group consisting of tension provided by soft tissue, load application during surgery, limb movement during surgery, and a combination thereof.

2. The device according to claim 1, wherein the plurality of force sensors that are placed at the periphery of the joint head cavity comprise three force sensors, each force sensor being located approximately 90°

from an adjacent force sensor.

3. The device according to claim 1, wherein the joint head is at least partially spherically shaped.

4. The device according to claim 3, wherein the joint head is shaped as an anatomical structure from the group consisting of a femoral head, a humeral head, and a combination thereof.

5. The device according to claim 1, wherein the stem is the implant and the joint head is a trial joint head dimensioned as an implant for measuring in vivo forces during surgery.

6. The device according to claim 2, wherein the stem attachment structure includes a recess for receiving insertion of the stem.

7. The device according to claim 1, wherein the force sensor is a strain sensor.

8. A kit for assisting joint replacement procedures, the kit comprising:

an intraoperative joint head having a cavity for accepting the insertion of a stem attachment structure;

a stem attachment structure being removably attachable to a stem and removably insertable in the joint head cavity;

a plurality of force sensors disposed within the joint head for measuring in vivo forces during surgery;

wherein the force sensors are placed at the periphery of the joint head cavity and the distance between adjacent force sensors is uniform, and at least one force sensors is located coaxial with a longitudinal axis of the stem such that the plurality of force sensors measure joint component forces to determine the resultant joint vector;

wherein the in vivo forces are generated from the group consisting of tension provided by soft tissue, load application during surgery, limb movement during surgery, and a combination thereof; and

an intraoperative joint head tool.

9. The kit according to claim 8, wherein the joint head includes at least one series of joint heads, each joint head providing at least one unique dimension relative to the joint heads in the series, the dimension selected from the group consisting of joint head radius, joint head cavity depth, cavity taper, trunion dimension and a combination thereof.

10. The kit according to claim 8, wherein the stem attachment structure is removably insertable in the joint head and includes at least one series of stem attachment structures, each stem attachment structure providing at least one unique dimension relative to the stem attachment structures in the series, the dimension selected from the group consisting of stem attachment length, stem attachment taper and a combination thereof.

11. The kit according to claim 8, wherein the intraoperative joint head tool includes a tool selected from the group consisting of an assembly tool and a disassembly tool.

12. A method of performing joint replacement surgery, comprising the steps of:

installing an intraoperative joint head having a cavity for accepting the insertion of a stem attachment structure;

a stem attachment structure being removably attachable to a stem and removably insertable in the joint head cavity;

a plurality of force sensors disposed within the joint head for measuring in vivo forces during surgery;

wherein the force sensors are placed at the periphery of the joint head cavity and the distance between adjacent force sensors is uniform, and at least one force sensor is located coaxial with a longitudinal axis of the stem such that the plurality of force sensors measure joint component forces to determine the resultant joint vector; and

wherein the in vivo forces are generated from the group consisting of tension provided by soft tissue, load application during surgery, limb movement during surgery, and a combination thereof;

measuring joint forces;

determining the resultant joint force vector; and

adjusting an implant parameter based on the measured joint forces.

13. The method according to claim 12, further comprising the step of applying a force to the joint.

14. The method according to claim 12, further comprising the step of applying a motion to the joint.

15. The method according to claim 12, wherein the implant parameter is selected from the group consisting of a stem dimension, a joint head dimension, stem attachment structure dimension, cavity taper, trunion dimension and a combination thereof.

16. The method according to claim 12, further comprising the step of implanting an implant based on the measured joint forces.

17. The method according to claim 12, further comprising the steps of obtaining anatomical measurements;

and

selecting a stem dimension, a joint head dimension, stem attachment structure dimension, and a combination thereof based on the measured joint forces, the anatomical measurements and a combination thereof.

18. The method according to claim 12, further comprising the steps of obtaining anatomical measurements;

and

implanting an implant based on the measured joint forces, the anatomical measurements and a combination thereof.

19. A surgical system for measuring joint forces during surgery, comprising:

an intraoperative joint head having a cavity for accepting the insertion of a stem attachment structure;

a stem attachment structure being removably attachable to a stem and removably insertable in the joint head cavity;

a plurality of force sensors disposed within the joint head for measuring in vivo forces during surgery;

wherein the force sensors are placed at the periphery of the joint head cavity and the distance between adjacent force sensors is uniform, and at least one force sensor is located coaxial with a longitudinal axis of the stem such that the plurality of force sensors measure joint component forces to determine the resultant joint vector; and

wherein the in vivo forces are generated from the group consisting of tension provided by soft tissue, load application during surgery, limb movement during surgery, and a combination thereof;

an anatomical tracking system for tracking movements of body parts, the system in communication with the force sensor; and

a processor in communication with the anatomical tracking system and the force sensor, the processor programmed to provide calculations selected from the group consisting of in vivo joint reaction forces and in vivo joint vectors.