Blockable bone plate

• US 6,730,091 B1
• Filed: 11/02/2001
• Issued: 05/04/2004
• Est. Priority Date: 05/03/1999
• Status: Expired due to Fees

• Current Assignee: Medartis AG (Medartis Holding AG)
• Original Assignee: Medartis AG (Medartis Holding AG)
• Inventors: Roth, Michael, Scheuble, Peter, Pfefferle, Joachim, Zeuner, Hermann
• Primary Examiner(s): Philogene, Pedro
• Application Number:
  US09/959,653
• Time in Patent Office: 914 Days
• Field of Search: 606/70, 606/69, 606/71, 606/72, 606/73, 606/104, 606/60, 606/62, 606/64
• US Class Current: 606/70
• CPC Class Codes: A61B 17/8057 the interlocking form comprising a thread
• CPC Class Codes: A61B 17/8071 for the jaw
• CPC Class Codes: A61B 17/8085 with pliable or malleable elements or having a mesh-like structure, e.g. small strips A61B17/8071, A61B17/8076 take precedence
• CPC Class Codes: A61B 17/863 with thread interrupted or changing its form along shank, other than constant taper

Abstract

The blockable bone plate consists of a plurality of plate members which are connected to each other via webs. A screw hole is provided in at least some plate members, preferably in each plate member. The screw hole is surrounded by a spherical countersink on the upper surface of the plate. Provided internally in the screw hole there is an engagement contour which consists of contour valleys and contour peaks partially running in a horizontal and radial peripheral direction on the wall of the screw hole. The engagement contour is preferably produced by milling and has for example a pointed, round, trapezoidal or serrated configuration. A blocking thread is provided under the screw head of the screw intended for blocking. As the screw is screwed in, the blocking thread engages in the engagement contour. The particular advantages lie in increased security against the screw coming loose and in the possibility of also inserting the screw through the plate at an inclination. Furthermore, a bone plate is proposed which has the shape of an arc of a circle in the longitudinal axis of the plate and which requires less bending, particularly on the human lower jaw, and adapts to the bone in a more ideal manner.

Claims

1. A blockable bone plate comprising:

a plurality of plate members which are connected to each other via waist-like webs and lie on a plate plane in an unbent state;

a bone screw hole in at least some plate members;

one or more bone screws which can be introduced through the screw holes for securing the bone plate, wherein each bone screw has a screw head which is thickened in diameter, a blocking thread situated below the screw head, the blocking thread having a pitch angle, and a bone thread which extends at least partially over a screw shank, the screw shank having a smaller cross-sectional diameter than the screw head; and

an engagement contour inside the screw hole for blocking of the bone plate by the blocking thread provided on the bone screw, wherein

the engagement contour comprises contour valleys and adjacent contour peaks, which are arranged at least substantially horizontally and partially running peripherally on the wall of the screw hole,

in relation to the plate plane, there is no orientation, as in the thread, between one contour valley and the next contour valley, and between one contour peak and the next contour peak,

the valleys and peaks of the engagement contour do not extend at a pitch angle, and

the blocking thread of the bone screw and the engagement contour of the screw hole are not complementary to each other.

2. The blockable bone plate as claimed in claim 1, wherein the screw hole has a spherical countersink on an upper surface of the plate for partially receiving a lower portion of the screw head for centering the bone screw, and having an oblong-shaped hole at an exit on a lower surface of the plate.

3. The blockable bone plate as claimed in claim 1, wherein the blocking thread of the bone screw includes at least one thread and can have a geometry different than or identical to the bone thread so the bone thread can be self-boring and/or self-tapping.

4. The blockable bone plate as claimed in claim 1 wherein the contour valleys and the contour peaks are oriented along a longitudinal axis of the plate or at an angle to the longitudinal axis.

5. The blockable bone plate as claimed in claim 1 wherein the engagement contour is similar to one of a pointed, a round, a trapezoidal, and a serrated thread.

6. The blockable bone plate as claimed in claim 2 wherein the engagement contour runs out at the horizontally located ends, so that wall areas remain in the screw hole and uncontoured wall areas lie on a theoretical main axis of the oblong-shaped screw hole in the area of the engagement contour.

7. The blockable bone plate as claimed in claim 1 wherein the bone screws are configured to be inserted into the screw holes vertically or with an angular offset in relation to a longitudinal axis of the plate and the plate plane.

8. The blockable bone plate as claimed in claim 1 further comprising bend edges developed by deformation on the blocking thread and on the engagement contour during blocking and providing increased security against the bone screw coming loose.

9. The blockable bone plate as claimed in claim 1 wherein a distance between adjacent contour valleys and contour peaks is in the range between 0.5 mm and 1.0 mm.

10. The blockable bone plate as claimed in claim 1 wherein the screw holes are configured such that bone screws without a blocking thread can be inserted vertically or obliquely into the screw holes.

11. The blockable bone plate as claimed in claim 1 wherein the longitudinal axis of the bone plate extending in the plate plane is at least substantially an arc of a circle.

12. The blockable bone plate as claimed in claim 11 wherein, as a result of the arc-shaped longitudinal axis of the plate, an offset of from about 1°

to about 10°

is obtained between the center axis of the webs and the center axis of the respectively adjacent screw hole.

13. The blockable bone plate as claimed in claim 11 wherein one or more screw holes is one of a cylindrical standard screw hole and an oriented compression screw hole.

14. The blockable bone plate as claimed in claim 11 wherein the bone plate further comprises a main segment with a plate longitudinal axis in an arc of a circle, a straight or curved lateral segment adjoining the main segment at at least one end, the lateral segment extending in the plate plane, and an angled segment extending in the plate plane between the main segment and the lateral segment.

15. The blockable bone plate as claimed in claim 14 wherein the angled segment is strengthened relative to the webs connecting the plate members and has no holes or has at least one of a screw hole including the engagement contour for blocking, a cylindrical standard screw hole, and an oriented compression hole and wherein the lateral segment is provided with at least one of screw holes having the engagement contour for blocking, cylindrical standard screw holes, and oriented compression screw holes.

17. The blockable bone plate as claimed in claim 11 wherein the bone plate is configured for the substantially horizontal, U-shaped engagement of the human jaw bone, in particular the lower jaw, where the ends of the bone plate, which consists only of a main segment or of one or two additional lateral segments, are dimensioned so as to engage over at least one ascending branch of the jaw.

16. The blockable bone plate as claimed claim in 11 wherein the arc of the bone plate is produced without deforming the bone plate.

18. A blockable bone plate comprising:

a plurality of plate members which are connected to each other via waist-like webs and lie on a plate plane in an unbent state;

a bone screw hole in at least some plate members;

at least one bone screw which can be introduced through the screw holes for securing the bone plate, wherein at least one bone screw has a screw head, a blocking thread situated opposite the screw head, the blocking thread having a pitch angle, and a bone thread which extends at least partially over a screw shank, the screw shank having a smaller cross-sectional diameter than the screw head;

an engagement contour inside the screw hole for blocking of the bone plate by the blocking thread, wherein

the engagement contour comprises contour valleys and adjacent contour peaks partially running peripherally on an inner wall of the screw hole, and, in relation to the plate plane, there is no orientation as a thread between one contour valley, and the next contour valley and between one contour peak and the next contour peak so that the valleys and peaks of the engagement contour do not extend at a pitch angle and the blocking thread of the bone screw and the engagement contour of the screw hole are not complementary to each other,

the screw hole has a spherical countersink on an upper surface of the plate for partially receiving a lower portion of the screw head and for centering the bone screw, and is an oblong hole on a lower surface of the plate, and

the engagement contour tapers and is absent at horizontally located ends of the hole, so that uncontoured wall areas of the screw hole lie on a theoretical main axis of the oblong hole.

19. The blockable bone plate as claimed in claim 18, wherein the blocking thread of the bone screw includes at least one thread geometrically different from or identical to the bone thread, so the bone thread can be self-boring and/or self-tapping.

20. The blockable bone plate as claimed in claim 18, wherein the contour valleys and the contour peaks are oriented along a longitudinal axis of the plate or at an angle to the longitudinal axis.

21. The blockable bone plate as claimed in claim 18, wherein the engagement contour is similar to one of a pointed, a round, a trapezoidal, and a serrated thread.

22. The blockable bone plate as claimed in claim 18, wherein the bone screws are configured to be inserted into the screw holes perpendicular to or with an angular offset in relation to a longitudinal axis of the bone plate and the plate plane.

23. The blockable bone plate as claimed in claim 18, further comprising bent edges developed by deformation on the blocking thread and on the engagement contour, during blocking, and providing increased security against the bone screw coming loose.

24. The blockable bone plate as claimed in claim 18, wherein distance between adjacent contour valleys and contour peaks is in the range between 0.5 mm and 1.0 mm.

25. The blockable bone plate as claimed in claim 18, wherein the screw holes are configured such that bone screws without blocking thread can be inserted into the screw holes.

26. The blockable bone plate as claimed in claim 18 wherein a longitudinal axis of the bone plate extending in the plate plane is at least substantially an arc of a circle.

27. The blockable bone plate as claimed in claim 26, wherein as a result of the circular arc-shaped longitudinal axis of the plate, an offset of from about 1°

to about 10°

is obtained between a center axis of the webs and a center axis of the respectively adjacent screw hole.

28. The blockable bone plate as claimed in claim 26, wherein at least one of the screw holes is one of a cylindrical standard screw hole and an oriented compression screw hole.

29. The blockable bone plate as claimed in claim 26 wherein the bone plate further comprises a main segment with a plate longitudinal axis in one of an arc of a circle, and a straight or curved lateral segment adjoining the main segment at at least one end, the lateral segment extending in the plate plane, and an angled segment extending in the plate plane between the main segment and the lateral segment.

30. The blockable bone plate as claimed in claim 29 wherein the angled segment is strengthened relative to the webs connecting the plate members and has no holes or has at least one of a screw hole including the engagement contour for blocking, a cylindrical standard screw hole, and an oriented compression hole, and wherein the lateral segment includes at least one of screw holes having the engagement contour for blocking, cylindrical standard screw holes, and oriented compression screw holes.

32. The blockable bone plate as claimed in claim 26 wherein the bone plate is configured for the substantially horizontal, U-shaped engagement of the human jaw bone, in particular the lower jaw, where ends of the bone plate, which consists only of a main segment or of one or two additional lateral segments, are dimensioned to engage more than at least one ascending branch of the jaw.

31. The blockable bone plate as claimed claim in 26 wherein the arc of the bone plate is produced without deforming the bone plate.