Process and device for the preoperative determination of the positioning data of endoprosthetic parts

• US 20020095083A1
• Filed: 03/08/2002
• Published: 07/18/2002
• Est. Priority Date: 03/11/1997
• Status: Active Grant

• Current Assignee: Aesculap AG (Lonza Group AG)
• Original Assignee: Aesculap AG (Lonza Group AG)
• Inventors: Picard, Frederic, Cinquin, Philippe, Leitner, Francois, Lavallee, Stephane, Minfelde, Richard, Saragaglia, Dominique, Schulz, Hans-Joachim
• Granted Patent: US 6,915,150 B2
• Time in Patent Office: Days
• US Class Current: 600/407
• CPC Class Codes: A61B 17/15 Guides therefor arrangements for guiding straight saw blades in general B23D51/025
• CPC Class Codes: A61B 17/154 for preparing bone for knee prosthesis
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 17/157 Cutting tibia
• CPC Class Codes: A61B 2017/00115 with audible or visual output
• CPC Class Codes: A61B 2017/00725 Calibration or performance testing
• CPC Class Codes: A61B 2034/107 Visualisation of planned trajectories or target regions
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 2034/2068 using pointers, e.g. pointers having reference marks for determining coordinates of body points
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• CPC Class Codes: A61B 2090/363 Use of fiducial points
• CPC Class Codes: A61B 2090/3929 Active markers
• CPC Class Codes: A61B 2090/3945 Active visible markers, e.g. light emitting diodes
• CPC Class Codes: A61B 2090/3979 infrared
• CPC Class Codes: A61B 2090/3983 Reference marker arrangements for use with image guided surgery
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/107 Measuring physical dimensions, e.g. size of the entire body or parts thereof
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/6878 Bone
• CPC Class Codes: A61B 90/06 : Measuring instruments not otherwise provided for
• CPC Class Codes: A61B 90/10 : for stereotaxic surgery, e.g. frame-based stereotaxis
• CPC Class Codes: A61B 90/36 : Image-producing devices or illumination devices not otherwise provided for
• CPC Class Codes: A61B 90/39 : Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61F 2/38 : for elbows or knees
• CPC Class Codes: A61F 2/4657 : Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• 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: G01S 15/872 : Combination of several systems for attitude determination using inertial means G01C9/00, control of attitude G05D1/49
• CPC Class Codes: G01S 17/87 : Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 5/163 : Determination of attitude using inertial means G01C9/00; control of attitude G05D1/49
• CPC Class Codes: G01S 5/186 : Determination of attitude using inertial means G01C9/00; control of attitude G05D1/49
• CPC Class Codes: Y10S 128/92 : Computer assisted medical diagnostics
• CPC Class Codes: Y10S 623/901 : Method of manufacturing prosthetic device

Abstract

In order to be able to ascertain the position of the bone in the body without complicated procedures in a process for the preoperative determination of the positioning data of endoprosthetic parts of a central joint relative to the bones forming the central joint, a respective outer articular point is determined by way of movement of the bones about a respective outer joint which is located at the end of the two bones facing away from the central joint. An articular point is determined for each of the two bones in the area of the central joint, and a direction characteristic for each of these bones is determined by way of a straight-line connection of the two articular points obtained in this manner for the two bones. The orientation of the endoprosthetic parts relative to this characteristic direction is then determined. Apparatus for carrying out the process is also provided.

Claims

1. A process for the preoperative determination of positioning data of endoprosthetic parts of a knee joint relative to a thigh bone and a lower leg bone forming the knee joint, comprising the steps of:

moving the thigh bone of the knee joint relative to a corresponding hip joint, to determine a first articular point in the area of the hip joint for said thigh bone;

determining a second articular point in the area of the knee joint for said thigh bone;

determining a first characteristic direction for said thigh bone by way of a straight-line connection of the first and second articular points; and

determining an orientation of the endoprosthetic parts relative to the first characteristic direction.

2. A method in accordance with claim 1, wherein:

said first articular point corresponds to a central point of said hip joint; and

said second articular point corresponds to an intersection point of a plurality of curves of maximum invariance generated by movement, relative to one another, of the thigh bone and the lower leg bone at the knee joint.

3. A method in accordance with claim 1, comprising the further steps of:

moving the lower leg bone of the knee joint relative to a corresponding ankle joint, to determine a third articular point in the area of the ankle joint for said lower leg bone;

determining a fourth articular point in the area of the knee joint for said lower leg bone bone;

determining a second characteristic direction for said lower leg bone by way of a straight-line connection of the third and fourth articular points; and

determining the orientation of the endoprosthetic parts relative to the first and second characteristic directions.

4. A method in accordance with claim 3, wherein:

said third articular point corresponds to an intersection point of pivot axes of the ankle joint about an axis extending transversely in relation to the lower leg bone; and

said fourth articular point corresponds to an intersection point of a plurality of curves of maximum invariance generated by movement, relative to one another, of the lower leg bone and the thigh bone at the knee joint.

5. A method in accordance with claim 1, wherein said second articular point is determined by way of movement, relative to one another, of the thigh bone and the lower leg bone forming the knee joint.

6. A method in accordance with claim 1, wherein the articular points are determined with a set of data reproducing the contour of the joint surface at the knee joint.

7. A method in accordance with claim 6, wherein the set of data of the contour of the joint surface is determined by scanning the joint surface and storing a plurality of positioning data of points on the joint surface.

8. A method in accordance with claim 1, wherein for the orientation of the endoprosthetic parts, sawing planes serving as contact surfaces for the endoprosthetic parts are determined, said planes taking up predetermined orientation relative to the characteristic direction.

9. A method in accordance with claim 8, wherein the sawing planes are at right angles to the characteristic direction.

10. A method in accordance with claim 8, wherein the sawing planes are arranged at a specific distance from the second articular point.

11. A method in accordance with claim 1, wherein movement of the bones for determining the articular points is carried out by means of a drive device.

12. A method in accordance with claim 1, comprising the further steps of:

securely connecting the thigh bone and a pelvis bone of the hip joint to marking elements for determining the first articular point; and

determining the respective positions of the marking elements by a measuring device generating signals corresponding to the respective positions and supplying the signals to a data processing system.

13. A method in accordance with claim 3, comprising the further steps of:

securely connecting the thigh bone and a pelvis bone of the hip joint to marking elements for determining the first articular point;

securely connecting the lower leg bone and an ankle bone to marking elements for determining the third articular point; and

determining the respective positions of the marking elements by a measuring device generating signals corresponding to the respective positions and supplying the signals to a data processing system.

14. A method in accordance with claim 13, wherein:

the marking elements comprise one of radiation emitters and reflecting surfaces; and

the measuring device comprises several radiation receivers.

15. A method in accordance with claim 1, wherein a sawing jig is aligned relative to the first characteristic direction of the bone for marking a sawing plane.

16. A method in accordance with claim 15, wherein the alignment is carried out by means of a robot.

17. A method in accordance with claim 15, wherein the alignment is carried out manually and the orientation of the sawing jig relative to the first characteristic direction is thereby continuously determined as a result of measurement of the orientation of said jig.

18. A method in accordance with claim 17, wherein:

difference signals are generated for observing deviation of the orientation of the sawing jig in relation to the first characteristic direction; and

said difference signals are minimal with a correct orientation and are indicated optically or acoustically.

19. A method in accordance with claim 18, wherein the difference signals are indicated by means of lines inclined relative to one another, said lines extending parallel to one another with a correct orientation.

20. A method in accordance with claim 19, wherein the lines intersect.

21. A method in accordance with claim 18, wherein the difference signals are indicated by means of the distance between two parallel lines, the distance between said lines disappearing with a correct orientation.

22. A method in accordance with claim 18, wherein the difference signals are represented by tones having at least one of varying loudness and varying frequency.

23. A method in accordance with claim 18, wherein two separate difference signals are generated for angular deviations in planes extending at right angles to one another.

24. A method in accordance with claim 1, wherein the positioning data determined on the basis of the first characteristic direction is used to control a machining robot.

26. A device in accordance with claim 25, wherein:

said first articular point corresponds to a central point of the hip joint; and

said second articular point corresponds to an intersection point of a plurality of curves of maximum invariance generated by movement, relative to one another, of the thigh bone and the lower leg bone at the knee joint.

27. A device in accordance with claim 25, further comprising:

at least one marking element securable to each of the lower leg bone and an ankle bone forming an ankle joint; and

said data processing system is responsive to the signals during the movement of the lower leg bone relative to the ankle joint to determine the point of greatest invariance at the ankle joint as a third articular point;

wherein;

a fourth articular point is determined in the area of the central joint for said lower leg bone; and

a second characteristic direction is determined for the lower leg bone from the position of the third articular point and the fourth articular point.

28. A device in accordance with claim 27, wherein:

said third articular point corresponds to an intersection point of pivot axes of the ankle joint about an axis extending transversely in relation to the lower leg bone; and

said fourth articular point corresponds to an intersection point of a plurality of curves of maximum invariance generated by movement, relative to one another, of the lower leg bone and the thigh bone at the knee joint.

29. A device in accordance with claim 25, wherein a scanning instrument is associated with the data processing system for supplying signals corresponding to its positioning to the data processing system.

30. A device in accordance with claim 29, wherein the data processing system generates a set of data describing the course of the joint surface from a plurality of signals generated by application of the scanning instrument to a joint surface of at least one of the bones adjoining the knee joint.

31. A device in accordance with claim 25, wherein the data processing system determines sawing planes for the orientation of the endoprosthetic parts, said sawing planes serving as contact surfaces for endoprosthetic parts and taking up a predetermined orientation relative to the characteristic direction.

32. A device in accordance with claim 31, wherein the sawing planes are at right angles to the characteristic direction.

33. A device in accordance with claim 31, wherein the sawing planes are arranged at a specific distance from the second articular point.

34. A device in accordance with claim 25, further comprising a drive device for moving bones relative to respective joints.

35. A device in accordance with claim 25, wherein:

the marking elements comprise one of radiation emitters and reflecting surfaces; and

the measuring device comprises several radiation receivers.

36. A device in accordance with claim 25, further comprising a robot, said robot aligning at least one of a tool jig and a tool relative to the characteristic direction.

37. A device in accordance with claim 25, wherein a marking element with an orientation determined by the measuring device is associated with at least one of a tool and a tool jig, so that signals corresponding to the orientation are transferred to the data processing system.

38. A device in accordance with claim 37, wherein the data processing system determines the orientation of the tool or the tool jig relative to the characteristic direction.

39. A device in accordance with claim 37, wherein:

the data processing system generates difference signals for observing deviation in the orientation of the sawing jig in relation to the characteristic direction;

the data processing system indicating the difference signals optically or acoustically; and

said signals are minimal with a correct orientation.

40. A device in accordance with claim 39, wherein the difference signals are indicated by way of lines inclined relative to one another, said lines extending parallel to one another with a correct orientation.

41. A device in accordance with claim 40, wherein said lines intersect.

42. A device in accordance with claim 39, wherein the difference signals are indicated by means of the distance between two parallel lines, the distance between said lines disappearing with a correct orientation.

43. A device in accordance with claim 39, wherein the difference signals are represented by tones having at least one of varying loudness and varying frequency.

44. A device in accordance with claim 39, wherein two separate difference signals are generated for angular deviations in planes extending at right angles to one another.

25. A device for the preoperative determination of positioning data of endoprosthetic parts of a knee joint relative to a thigh bone and a lower leg bone forming the knee joint, comprising:

at least one marking element securable to each of the thigh bone and a pelvis bone forming a hip joint;

a measuring device for determining the position of the marking elements in space;

a data processing system adapted to receive signals corresponding to positioning data of the marking elements from the measuring device; and

said data processing system is responsive to the signals during movement of the thigh bone relative to the hip joint to determine the point of greatest invariance at the hip joint as a first articular point;

wherein;

a second articular point is determined in the area of the knee joint for said thigh bone; and

a first characteristic direction is determined for the thigh bone from the position of the first articular point and the second articular point.