Bone screw

• US 20020123752A1
• Filed: 01/24/2002
• Published: 09/05/2002
• Est. Priority Date: 08/14/1999
• Status: Active Grant

• Current Assignee: Aesculap AG (B. Braun Holding GmbH & Co. KG)
• Original Assignee: Aesculap AG (B. Braun Holding GmbH & Co. KG)
• Inventors: Schultheiss, Markus, Claes, Lutz, Kinzl, Lothar
• Granted Patent: US 6,755,835 B2
• Time in Patent Office: Days
• US Class Current: 606/73
• CPC Class Codes: A61B 17/7098 wherein the implant is permeable or has openings, e.g. fenestrated screw hollow surgical screws A61B17/864
• CPC Class Codes: A61B 17/864 hollow, e.g. with socket or cannulated
• CPC Class Codes: A61B 17/8685 comprising multiple separate parts

Abstract

In order to produce a bone screw having a screw body which is provided with an external thread and which comprises flow-through means for bone cement that is used for the production of a cement jacket around the bone screw, such that the bone screw will be anchored in a highly stable manner after being implanted in a bone and especially after being implanted in a bone of reduced quality, it is proposed that the flow-through means should comprise at least one longitudinal recess which is formed in the screw body such that it extends transversely relative to the radial direction and transversely relative to the peripheral direction.

Claims

1. A bone screw having a screw body which is provided with an external thread and which comprises flow-through means for bone cement that is used for the production of a cement jacket around the bone screw, wherein the flow-through means comprises at least one longitudinal recess which is formed in the screw body such that it extends transversely relative to a radial direction and transversely relative to a peripheral direction, and the dimensions of said at least one longitudinal recess in the longitudinal direction thereof are such that it extends over a plurality of turns of the external thread.

2. A bone screw in accordance with claim 1, wherein said at least one longitudinal recess is perpendicular to a radial direction.

3. A bone screw in accordance with claim 1, wherein said at least one longitudinal recess is perpendicular to a peripheral direction.

4. A bone screw in accordance with claim 1 wherein the flow-through means comprise a hollow channel formed in the screw body and said at least one longitudinal recess is connected to the hollow channel.

5. A bone screw in accordance with claim 4, wherein said at least one longitudinal recess is connected to the hollow channel in the longitudinal direction of said recess.

6. A bone screw in accordance with claim 1 wherein said at least one longitudinal recess has corresponding recesses associated therewith in the turns of the external thread.

7. A bone screw in accordance with claim 6, wherein a turn of the external thread is broken-through in the vicinity of said at least one longitudinal recess.

8. A bone screw in accordance with claim 1, wherein said at least one longitudinal recess is in the form of a slot.

9. A bone screw in accordance with claim 8, wherein a plane of the slot is substantially perpendicular to a peripheral direction of the screw body.

10. A bone screw in accordance with claim 8, wherein a plane of the slot is substantially radial taken with respect to the screw body.

11. A bone screw in accordance with claim 8, wherein a plane of the slot lies substantially in the longitudinal direction taken with respect to the screw body.

12. A bone screw in accordance with claim 1 wherein a plurality of longitudinal recesses are arranged over the periphery of the screw body.

13. A bone screw in accordance with claim 12, wherein three longitudinal recesses are arranged over the periphery of the screw body.

14. A bone screw in accordance with claim 12, wherein the plurality of longitudinal recesses are substantially symmetrical relative to a longitudinal axis of the screw body.

15. A bone screw in accordance with claim 1 and comprising successive sections in the longitudinal direction of the screw body which sections differ in regard to the construction of the outer surfaces thereof.

16. A bone screw in accordance with claim 15, wherein a frontal section of the screw body is substantially conical or is in the form of a truncated cone.

17. A bone screw in accordance with claim 16, wherein an envelope of the turns of the external thread in the frontal section is substantially conical or is in the form of a truncated cone.

18. A bone screw in accordance with claim 16 wherein an envelope of the screw body in the frontal section is substantially conical or is in the form of a truncated cone.

19. A bone screw in accordance with claim 15 wherein a central section of the screw body is substantially cylindrical.

20. A bone screw in accordance with claim 19, wherein an envelope of the turns in the central section is substantially cylindrical.

21. A bone screw in accordance with claim 19, wherein an envelope of the screw body in the central section is substantially cylindrical.

22. A bone screw in accordance with claim 15 wherein a hollow channel in the screw body is led through the central section.

23. A bone screw in accordance with claim 15 wherein said at least one longitudinal recess is arranged substantially in the central section.

24. A bone screw in accordance with claim 15 wherein a rear section of the screw body is substantially conical or is in the form of a truncated cone.

25. A bone screw in accordance with claim 24, wherein an envelope of the screw body in the rear section is substantially conical or is in the form of a truncated cone.

26. A bone screw in accordance with claim 24, wherein an envelope of the turns of the external thread in the rear section is substantially cylindrical.

27. A bone screw in accordance with claim 26, wherein an envelope of the turns in the rear section and of the turns in the central section coincides.

28. A bone screw in accordance with claim 23, wherein the angle of the cone in the frontal section substantially corresponds to the angle of the cone in the rear section.

29. A bone screw in accordance with claim 15, wherein the turns of the external thread are provided with longitudinal break-throughs in a region in which there are no longitudinal recesses.

30. A bone screw in accordance with claim 1, wherein a surface of the screw body between adjacent turns of the external thread is substantially parallel to the longitudinal direction of the screw body.

31. A bone screw in accordance with claim 15, wherein a surface of the screw body between adjacent turns of the external thread is substantially parallel to the longitudinal direction of the screw body.

32. A bone screw in accordance with claim 4 wherein the hollow channel is in the form of a blind bore.

33. A bone screw in accordance with claim 1, wherein the screw body is provided with an internal thread.

34. A bone screw in accordance with claim 1, wherein a screw head for insertion in the screw body is provided with a channel.

35. A bone screw in accordance with claim 1, wherein the screw body comprises a coupling element for a bone cement applicator.

36. A bone screw in accordance with claim 35, wherein the coupling element comprises a seating arrangement for a nozzle of a bone cement applicator.

37. A bone screw in accordance with claim 1, wherein a diameter of the screw body is greater than a pitch of the external thread.

38. A bore screw in accordance with claim 15, wherein a diameter of the screw body is greater than the pitch of external thread.

39. A bone screw in accordance with claim 1, wherein a bone screw comprises approximately seven to twelve peripheral turn s of the external thread.

40. A bone screw in accordance with claim 1, wherein the external thread is constructed in such a manner that the bone screw is self-tapping.