SPINAL MEASURING DEVICE AND DISTRACTOR

• US 20100010494A1
• Filed: 11/19/2008
• Published: 01/14/2010
• Est. Priority Date: 07/11/2008
• Status: Active Grant

• Current Assignee: Q-Spine LLC
• Original Assignee: Q-Spine LLC
• Inventors: Quirno, Martin
• Granted Patent: US 8,414,592 B2
• Time in Patent Office: Days
• US Class Current: 606/90
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61B 2090/061 for measuring dimensions, e.g. length
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2002/4658 for measuring dimensions, e.g. length
• CPC Class Codes: A61F 2002/4666 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2002/4668 for measuring angles

Abstract

A method and device for determining an optimal size of an intervertebral implant to be inserted within an intervertebral space between two vertebrae in a patient, comprising inserting a distractor into the intervertebral space. The vertebral endplate depth is measured by moving a posterior rod on the distractor longitudinally to a position at the posterior margin of the vertebral endplate and moving an anterior rod on the distractor to a position at the anterior margin of the vertebral endplate. The force applied during distraction is measured using at least one transducer mounted on the distractor and the intervertebral space is distracted by rotating the posterior and anterior rods on the distractor until the measured force reaches a predetermined value. The posterior height of the intervertebral space is measured based on the amount that the posterior rod is rotated and the anterior height of the intervertebral space is measured based on the amount that the anterior rod is rotated. The intervertebral angle is measured based on the angular orientation of two pivotally connected handles on the distractor.

Claims

1. A device for determining an optimal size of an intervertebral implant to be inserted within an intervertebral space between two vertebrae in a patient, comprising:

a movable posterior rod operatively connected to first and second posterior distracting members, the posterior distracting members being movable in opposing radial directions in response to rotation of the posterior rod, the posterior rod having markings corresponding to the distance that the posterior distracting members have moved for measuring posterior disc height;

a movable anterior rod operatively connected to first and second anterior distracting members, the anterior distracting members being movable in opposing radial directions in response to rotation of the anterior rod, the anterior rod having markings corresponding to the distance that the anterior distracting members have moved for measuring anterior disc height;

the posterior and anterior rods being movable in a longitudinal direction, the anterior rod including a linear scale and the posterior rod including a position indicator for measuring the distance between the distal end of the posterior rod and the distal end of the anterior rod;

the first posterior and anterior distracting members each having a terminal end that engages a first load sensor plate, the first load sensor plate being movable in response to movement of either the first posterior distracting member or the first anterior distracting member;

the second posterior and anterior distracting members each having a terminal end that engages a second load sensor plate, the second load sensor plate being movable in response to movement of either the second posterior distracting member or the second anterior distracting member;

a first handle pivotally connected to a proximal end of the first load sensing plate and a second handle pivotally connected to a proximal end of the second load sensing plate, the first and second handles pivotally connected to one another;

a protractor for measuring the angular orientation of the first and second handles; and

a transducer for measuring the force applied during distraction of the intervertebral space.

2. A method for determining an optimal size of an intervertebral implant to be inserted within an intervertebral space between two vertebrae in a patient, comprising:

inserting a distractor into the intervertebral space;

measuring a vertebral endplate depth by moving a posterior rod on the distractor longitudinally to a position at the posterior margin of the vertebral endplate and moving an anterior rod on the distractor to a position at the anterior margin of the vertebral endplate;

measuring a force applied during distraction with at least one transducer mounted on the distractor;

distracting the intervertebral space by rotating the posterior and anterior rods on the distractor until the measured force reaches a predetermined value;

measuring a posterior height of the intervertebral space based on an amount that the posterior rod is rotated;

measuring an anterior height of the intervertebral space based on an amount that the anterior rod is rotated;

measuring an intervertebral angle based on an angular orientation of two pivotally connected handles on the distractor; and

selecting the optimal size of the intervertebral implant corresponding to the measured vertebral endplate depth, posterior height, anterior height, and intervertebral angle.

3. A method for determining an optimal size of an intervertebral implant to be inserted within an intervertebral space between two vertebrae in a patient, comprising:

inserting a distractor into the intervertebral space;

measuring a vertebral endplate depth;

measuring an amount of force applied during distraction with at least one transducer mounted on the distractor;

distracting the intervertebral space;

measuring a posterior height of the intervertebral space;

measuring an anterior height of the intervertebral space;

measuring an intervertebral angle; and

selecting the optimal size of the intervertebral implant corresponding to the measured vertebral endplate depth, posterior height, anterior height, and intervertebral angle.

4. The method according to claim 3, wherein the vertebral endplate depth is measured by moving a posterior rod on the distractor longitudinally to a position at the posterior margin of the vertebral endplate and moving an anterior rod on the distractor to a position at the anterior margin of the vertebral endplate.

5. The method according to claim 4, wherein the vertebral endplate depth corresponds to a particular graduation on a ruler on the anterior rod that is aligned with a position indicator on the posterior rod.

6. The method according to claim 3, wherein the intervertebral space is distracted until the measured force reaches a predetermined value.

7. The method according to claim 6, wherein the intervertebral space is distracted by rotating the posterior and anterior rods on the distractor.

8. The method according to claim 6, further comprising displaying the force measured by the transducer.

9. The method according to claim 3, wherein the posterior height of the intervertebral space is measured based on an amount that the posterior rod is rotated.

10. The method according to claim 9, wherein the amount that the posterior rod is rotated is indicated by a particular graduation on a circumference of the posterior rod.

11. The method according to claim 3, wherein the anterior height of the intervertebral space is measured based on an amount that the anterior rod is rotated.

12. The method according to claim 11, wherein the amount that the anterior rod is rotated is indicated by a particular graduation on a circumference of the anterior rod.

13. The method according to claim 3, wherein the intervertebral angle is measured based on an angular orientation of two pivotally connected handles on the distractor.

14. The method according to claim 13, wherein the angular orientation of the two pivotally connected handles are measured using a particular graduation on a protractor corresponding to the angular orientation of affected vertebral endplates.

15. A device for determining an optimal size of an intervertebral implant to be inserted within an intervertebral space between two vertebrae in a patient, comprising:

a first plate operatively connected to a first handle and movable in response to movement of the first handle, the first plate insertable within the intervertebral space for engagement with a first vertebral endplate;

a second plate operatively connected to a second handle and movable in response to movement of the second handle, the second plate insertable within the intervertebral space for engagement with a second vertebral endplate; and

at least one transducer for measuring the force applied during distraction of the intervertebral space.

16. The device according to claim 15, wherein the first handle is a movable posterior rod and the second handle is a movable anterior rod,

the posterior rod operatively connected to first and second posterior distracting members, the posterior distracting members being movable in opposing radial directions in response to rotation of the posterior rod, and

the anterior rod operatively connected to first and second anterior distracting members, the anterior distracting members being movable in opposing radial directions in response to rotation of the anterior rod.

17. The device according to claim 16, wherein the first posterior and anterior distracting members each have a terminal end that engages the first plate, the first plate being movable in response to movement of either the first posterior distracting member or the first anterior distracting member.

18. The device according to claim 17, wherein the second posterior and anterior distracting members each have a terminal end that engages the second plate, the second plate being movable in response to movement of either the second posterior distracting member or the second anterior distracting member.

19. The device according to claim 18, wherein the posterior rod includes markings corresponding to the distance that the posterior distracting members have moved for measuring posterior disc height.

20. The device according to claim 18, wherein the anterior rod includes markings corresponding to the distance that the anterior distracting members have moved for measuring anterior disc height.

21. The device according to claim 16, wherein the posterior and anterior rods are movable in a longitudinal direction, the anterior rod including a linear scale and the posterior rod including a position indicator for measuring the distance between the distal end of the posterior rod and the distal end of the anterior rod.

22. The device according to claim 15, further comprising:

a first lever pivotally connected to a proximal end of the first plate and a second lever pivotally connected to a proximal end of the second plate, the first and second levers pivotally connected to one another; and

a protractor for measuring the angular orientation of the first and second levers.

23. The device according to claim 15, wherein the transducer is mounted on the first plate.

24. The device according to claim 23, further comprising a second transducer mounted on the second plate.

25. The device according to claim 16, wherein the posterior rod includes a plurality of teeth defining a gear and the posterior distracting members each include a plurality of teeth on at least one surface thereof for meshing engagement with the teeth on the posterior rod such that rotation of the posterior rod causes the posterior distracting members to move in opposing radial directions.

26. The device according to claim 25, wherein the anterior rod includes a plurality of teeth defining a gear and the anterior distracting members each include a plurality of teeth on at least one surface thereof for meshing engagement with the teeth on the anterior rod such that rotation of the anterior rod causes the anterior distracting members to move in opposing radial directions.

27. A device for determining an optimal size of an intervertebral implant to be inserted within an intervertebral space between two vertebrae in a patient, comprising:

a movable posterior rod operatively connected to at least one posterior distracting member, the posterior distracting member being movable in a radial direction in response to rotation of the posterior rod;

a movable anterior rod operatively connected to at least one anterior distracting member, the anterior distracting member being movable in a radial direction in response to rotation of the anterior rod; and

at least one transducer for measuring the force applied during distraction of the intervertebral space.

28. The device according to claim 27, further comprising first and second posterior distracting members operatively connected to the posterior rod, the posterior distracting members being movable in opposing radial directions in response to rotation of the posterior rod.

29. The device according to claim 28, wherein the posterior rod includes a plurality of teeth defining a gear and the posterior distracting members include a plurality of teeth on at least one surface thereof for meshing engagement with the teeth on the posterior rod such that rotation of the posterior rod causes the posterior distracting members to move in opposing radial directions.

30. The device according to claim 28, further comprising first and second anterior distracting members operatively connected to the anterior rod, the anterior distracting members being movable in opposing radial directions in response to rotation of the posterior rod.

31. The device according to claim 30, wherein the anterior rod includes a plurality of teeth defining a gear and the anterior distracting members include a plurality of teeth on at least one surface thereof for meshing engagement with the teeth on the anterior rod such that rotation of the anterior rod causes the anterior distracting members to move in opposing radial directions.

32. The device according to claim 27, wherein the posterior rod includes markings corresponding to the distance that the posterior distracting member has moved for measuring posterior disc height.

33. The device according to claim 27, wherein the anterior rod includes markings corresponding to the distance that the anterior distracting member has moved for measuring anterior disc height.

34. The device according to claim 27, wherein the posterior and anterior rods are movable in a longitudinal direction, the anterior rod including a linear scale and the posterior rod including a position indicator for measuring the distance between the distal end of the posterior rod and the distal end of the anterior rod.

35. The device according to claim 27, wherein the posterior distracting member includes a terminal end that engages a first load sensor plate, the first load sensor plate being movable in response to movement of the posterior distracting member.

36. The device according to claim 35, wherein the anterior distracting member includes a terminal end that engages a second load sensor plate, the second load sensor plate being movable in response to movement of the anterior distracting member.

37. The device according to claim 36, further comprising a first handle pivotally connected to a proximal end of the first load sensing plate and a second handle pivotally connected to a proximal end of the second load sensing plate, the first and second handles pivotally connected to one another.

38. The device according to claim 37, further comprising a protractor for measuring the angular orientation of the first and second handles.

39. The device according to claim 35, wherein the transducer is mounted on the first load sensing plate.

40. The device according to claim 36, wherein the transducer is mounted on the first load sensing plate.

41. The device according to claim 39, further comprising a second transducer mounted a second load sensing plate.

42. A device for determining an optimal size of an intervertebral implant to be inserted within an intervertebral space between two vertebrae in a patient, comprising:

means for measuring a vertebral endplate depth;

means for measuring a force applied during distraction;

means for measuring a posterior height of the intervertebral space;

means for measuring an anterior height of the intervertebral space; and

means for measuring an intervertebral angle.