Bone adjuster

• US 6,355,036 B1
• Filed: 05/12/2000
• Issued: 03/12/2002
• Est. Priority Date: 08/02/1999
• Status: Expired due to Fees

• Current Assignee: Bear Medic Corporation
• Original Assignee: Kyowa Precision Instruments Corp.
• Inventors: Nakajima, Hideo
• Primary Examiner(s): Philogene, Pedro
• Application Number:
  US09/570,428
• Time in Patent Office: 669 Days
• Field of Search: 606/57, 606/59, 606/54, 606/55, 606/56, 606/58, 606/60, 606/105, 606/69, 606/71
• US Class Current: 606/57
• CPC Class Codes: A61B 17/6433 specially adapted for use on body parts other than limbs, e.g. trunk or head
• CPC Class Codes: A61B 17/66 Alignment, compression or distraction mechanisms
• CPC Class Codes: A61B 17/663 for jaw bones, e.g. subcutaneous distractors with external access periodontal bone regeneration A61C8/0006

Abstract

A bone adjuster 20 has a first lift plate 22 to be fastened to one of two opposed bone fragments to be adjusted, a second lift plate 24 to be fastened to the other bone fragment and an adjusting shaft 26 which is extended between both the lift plates 22 and 24 to adjust a space between the fragments. The first lift plate 22 comprises a mounting plate 28 and a screw-in connecting portion 34 which is connected with the mounting plate 28 via a hinge 36 and in which the adjusting shaft 26 is screwed to be supported. The second lift plate 24 also comprises a mounting plate 42 and a catching portion 48 which is rotatably fixed to the mounting plate 42 via a hinge 46 to catch the leading end of the adjusting shaft 26. The screw-in connecting portion 34 and the catching portion 48 are supported on the mounting plates 28 and 42 at a desired angle by the hinges 36 and 46, so that the mounting plates 28, 42 can be installed parallel to each other even when the bone fragments are skewed so as to appropriately hold the adjusting shaft 26.

Claims

1. A bone adjuster comprising a first lift plate for fastening to one bone fragment, a second lift plate for fastening to another bone fragment, and an adjusting shaft which is screwed through the first lift plate and has its leading end engaged with the second lift plate, the adjusting shaft being rotated to adjust a distance between both the lift plates so to adjust a space between the opposed bone fragments, wherein:

the first lift plate is provided with a first mounting plate to be fastened to one of the bone fragments and a screw-in connecting portion which is connected to the first mounting plate and in which the adjusting shaft is screwed;

the second lift plate is provided with a second mounting plate to be fastened to the other bone fragment and a catching portion which is connected to the second mounting plate and holds the leading end of the adjusting shaft; and

at least the catching portion is connected to the second mounting plate via a hinge.

2. The bone adjuster according to claim 1, wherein both the screw-in connecting portion and the catching portion are pivotably connected to the first mounting plate and the second mounting plate via a hinge respectively.

3. The bone adjuster according to claim 1, wherein a stopping flange is formed on the end portion of the adjusting shaft so as to externally protrude from its outer periphery, the catching portion comprises a catching plate having a catching surface to engage with the stopping flange, and the catching plate is formed a holding hole in which the end of the adjusting shaft is inserted and held.

4. The bone adjuster according to claim 2, wherein a stopping flange is formed on the end portion of the adjusting shaft so as to externally protrude from its outer periphery, the catching portion comprises a catching plate having a catching surface to engage with the stopping flange, and the catching plate is formed with a holding hole into which one end of the adjusting shaft is inserted and held.

5. The bone adjuster according to claim 1, wherein the catching portion is further provided with a stopper to restrict the catching portion to pivot within a given range.

6. The bone adjuster according to claim 2, wherein the screw-in connecting portion and the catching portion are further provided with a stopper to restrict the screw-in connecting portion and the catching portion to pivot within a given range.

7. The bone adjuster according to claim 3, wherein the catching plate has:

an inside catching surface on the opposite side of the screw-in connecting portion to engage with the stopping flange so to expand the space between the bone fragments; and

an outside catching surface on the other side of the inside catching surface to engage with the stopping flange so to decrease the space between the bone fragments.

8. The bone adjuster according to claim 4, wherein the catching plate has:

an inside catching surface on the opposite side of the screw-in connecting portion to engage with the stopping flange so to expand the space between the bone fragments; and

an outside catching surface on the other side of the inside catching surface to engage with the stopping flange so to decrease the space between the bone fragments.

9. The bone adjuster according to claim 1, further comprising a hinge plate which is used, when at least one of the bone fragments is cut off at an appropriate point, to connect the cut-off ends so to enable at least one of the cut-off ends to pivot.

10. The bone adjuster according to claim 2, further comprising a hinge plate which is used, when at least one of the bone fragments is cut off at an appropriate point, to connect the cut-off ends so to enable at least one of the cut-off ends to pivot.

11. The bone adjuster according to claim 1, wherein at least one of the first lift plate and the second lift plate is provided with a reinforcing plate, the hinge is situated between the reinforcing plate and the respective mounting plate, and the reinforcing plate is provided with a fixing section to be fixed to a bone fragment.

12. The bone adjuster according to claim 2, wherein at least one of the first lift plate and the second lift plate is provided with a reinforcing plate, the hinge is situated between the reinforcing plate and the respective mounting plate, and the reinforcing plate is provided with a fixing section to be fixed to a bone fragment.

13. The bone adjuster according to claim 1, wherein the bone adjuster is formed of a material having little effect on the human body.

14. The bone adjuster according to claim 2, wherein the bone adjuster is formed of a material having little effect on the human body.

15. The bone adjuster according to claim 9, wherein the bone adjuster is formed of a material having little effect on the human body.

16. The bone adjuster according to claim 10, wherein the bone adjuster is formed of a material having little effect on the human body.

17. The bone adjuster according to claim 11, wherein the bone adjuster is formed of a material having little effect on the human body.

18. The bone adjuster according to claim 12, wherein the bone adjuster is formed of a material having little effect on the human body.