Modular lag screw

Patent metadata

Field	Value
Publication number	US-9320555-B2
Application number	US-201313755677-A
Country	US
Kind code	B2
Filing date	Jan 31, 2013
Priority date	Jan 31, 2013
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

An elongated modular implant is provided which has a distal part and a proximal part both having a leading end and a trailing end, respectively. The trailing end of the distal part includes a tool engagement portion and the leading end of the proximal part includes a distal part engagement portion for an engagement with the tool engagement portion of the distal part. The implant further includes an assembly element for firmly coupling the distal part and the proximal part when the first tool engagement portion of the distal part engages the distal part engagement portion of the proximal part. The proximal part trailing end may also have a tool engagement portion identical to the trailing end of the distal part.

First claim

The invention claimed is:

1. A bone screw comprising:
a distal part comprising a first leading end and a first trailing end, wherein the first trailing end includes a first tool engagement portion having at least one slot, and
a proximal part comprising a second leading end and a second trailing end, wherein the second leading end includes a distal part engagement portion having at least one protrusion for an engagement with the at least one slot of the first tool engagement portion of the first trailing end of the distal part, and wherein the second trailing end includes a second tool engagement portion having a plurality of slots forming the second tool engagement portion, wherein the second tool engagement portion corresponds to the first tool engagement portion of the distal part, and
an assembly element for firmly coupling the distal part and the proximal part when the first tool engagement portion of the distal part engages the distal part engagement portion of the proximal part.

2. The bone screw of claim 1 , wherein the first tool engagement portion is crown-shaped.

3. The bone screw of claim 1 , wherein the distal part engagement portion of the proximal part is formed so as to provide a form fit with the tool engagement portion of the distal part.

4. The bone screw of claim 1 , wherein the distal part engagement portion at the second leading end of the proximal part is formed for an engagement with the tool engagement portion at the first trailing end of the distal part, and wherein the second trailing end of the proximal part comprises a second tool engagement portion which corresponds to the first tool engagement portion.

5. The bone screw of claim 1 , wherein the proximal part comprises an end surface at the second trailing end section which corresponds to a shape of an outer bone surface at an intended implantation site so that the end surface of the bone screw is flush with the bone surface surrounding the end surface when the bone screw is inserted into the bone.

6. The bone screw of claim 5 , wherein the end surface at the second trailing end section is inclined with respect to a longitudinal axis of the bone screw.

7. The bone screw of claim 1 , wherein the distal part comprises an axial bore with an inner thread at the first trailing end, and the proximal part comprises an axial through bore with an enlarged section, wherein the assembly screw comprises a screw head being adapted to be received in the enlarged section in the proximal part and an outer screw thread being adapted to engage the inner thread in the distal part so as to firmly couple the distal part and the proximal part.

8. The bone screw of claim 1 , wherein the distal part and the proximal part are configured to move over a guide wire when the first tool engagement portion of the distal part engages the distal part engagement portion of the proximal part.

9. The bone screw as set forth in claim 1 wherein the first engagement portion comprises a recess and the proximal part distal part engagement portion comprises a protrusion for engaging the recess, the proximal part having a bore therethrough.

10. The bone screw as set forth in claim 9 wherein the assembly element extends through the bore in the proximal part.

11. A bone screw comprising:
a distal part comprising a first leading end and a first trailing end, wherein the first trailing end includes a first tool engagement portion with a plurality of slots, and
a proximal part comprising a second leading end and a second trailing end, wherein the second leading end includes a distal part engagement portion with at least one protrusion for an engagement with the a plurality of slots of the first tool engagement portion of the first trailing end of the distal part, and wherein the second trailing end includes a second tool engagement portion with a plurality of slots, wherein the plurality of slots of the first tool engagement portion of the distal part is engagable with the plurality of slots of the second tool engagement portion of the proximal part, and
an assembly element for firmly coupling the distal part and the proximal part when the first tool engagement portion of the distal part engages the distal part engagement portion of the proximal part, wherein the distal part comprises an axial bore with an inner thread at the first trailing end, and the proximal part comprises an axial through bore with an enlarged section, wherein the assembly screw comprises a screw head being adapted to be received in the enlarged section in the proximal part and an outer screw thread being adapted to engage the inner thread in the distal part so as to firmly couple the distal part and the proximal part.

12. The bone screw of claim 11 , wherein the first tool engagement portion is crown-shaped.

13. The bone screw of claim 11 , wherein the distal part engagement portion at the second leading end of the proximal part is formed for an engagement with the tool engagement portion at the first trailing end of the distal part, and wherein the second trailing end of the proximal part comprises a second tool engagement portion which corresponds to the first tool engagement portion.

14. The bone screw of claim 11 , wherein the proximal part comprises an end surface at the second trailing end section which corresponds to a shape of an outer bone surface at an intended implantation site so that the end surface of the bone screw is flush with the bone surface surrounding the end surface when the bone screw is inserted into the bone.

15. The bone screw of claim 14 , wherein the end surface at the second trailing end section is inclined with respect to a longitudinal axis of the bone screw.

16. The bone screw as set forth in claim 11 wherein the first engagement portion comprises a recess and the proximal part distal part engagement portion comprises a protrusion for engaging the recess, the proximal part having a bore therethrough.

17. A bone screw comprising:
a distal part comprising a first leading end and a first trailing end, wherein the first trailing end includes a first tool engagement portion having at least one slot, and
a proximal part comprising a second leading end and a second trailing end, wherein the second leading end includes a distal part engagement portion having at least one protrusion for an engagement with the at least one slot of the first tool engagement portion of the first trailing end of the distal part, and wherein the second trailing end includes a second tool engagement portion having a plurality of slots forming the second tool engagement portion, wherein the plurality of the slots of the second tool engagement portion of the proximal part corresponds to the first tool engagement portion, and
an assembly element for firmly coupling the distal part and the proximal part when the first tool engagement portion of the distal part engages the distal part engagement portion of the proximal part.

18. The bone screw of claim 17 , wherein the first tool engagement portion comprises at least one slot and the proximal portion distal part engagement portion comprises at least one protrusion for an engagement with the at least one slot.

19. The bone screw as set forth in claim 17 wherein the first engagement portion comprises a recess and the proximal part distal part engagement portion comprises a protrusion for engaging the recess, the proximal part having a bore therethrough.

Assignees

• Stryker Trauma Gmbh
• Stryker Europe Holdings I Llc

Inventors

• Probe Robert
• Paulsen Martje
• Simon Bernd

Classifications

• A61B17/744

  the longitudinal elements coupled to an intramedullary nail · CPC title

• A61B17/8685 Primary

  comprising multiple separate parts · CPC title

• A61B17/8605

  Heads, i.e. proximal ends projecting from bone · CPC title