Intramedullary nail and implant system comprising the nail

Patent metadata

Field	Value
Publication number	US-9358049-B2
Application number	US-201514682457-A
Country	US
Kind code	B2
Filing date	Apr 9, 2015
Priority date	Oct 1, 2012
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

An intramedullary nail has a posterior side, an anterior side, a proximal portion and a distal portion is described. A transverse bore is arranged in the proximal portion and is configured to receive a bone engagement member. The transverse bore includes at least two recesses formed at an inner wall of the transverse bore, wherein one recess is arranged on the posterior side and the other recess is arranged on the anterior side of the transverse bore of the intramedullary nail.

First claim

The invention claimed is:

1. A femoral fracture fixation system comprising:
a femoral intramedullary nail having a posterior side, an anterior side, a proximal portion, a distal portion;
a transverse bore arranged in the proximal portion, the transverse bore including a first and a second recess formed at an inner wall of the transverse bore, wherein the transverse bore has an inlet opening and wherein each of the first and second recess opens out into the inlet opening of the transverse bore, wherein the first recess is arranged on the posterior side and the second recess is arranged on the anterior side of the transverse bore of the intramedullary nail, and wherein the transverse bore has a bore axis and a length along the bore axis, wherein each of the first and second recesses have a conical shape in the direction of the bore axis that defines a length along the inner wall in a direction of the bore axis of the transverse bore and wherein the length of each recess is less than the length of the transverse bore;
a femoral screw slidably received within the transverse bore, the femoral screw having a threaded portion for engaging a head of a femur; and
an anti-rotation element moveable along a longitudinal axis of the proximal portion of the nail, and selectively contacting an outer surface of the femoral screw to prevent rotation of the screw.

2. The femoral fracture fixation system according to claim 1 , wherein each of the first and second recesses substantially extends in a direction of the bore axis of the transverse bore.

3. The femoral fracture fixation system according to claim 1 , wherein the first and second recesses substantially extend from a lateral side to a medial side of the intramedullary nail.

4. The femoral fracture fixation system according to claim 1 , wherein the first and second recesses have an oblique extension relative to an extension of the bore axis of the transverse bore.

5. The femoral fracture fixation system according to claim 1 , wherein the first and second recesses are concave in cross-section.

6. The femoral fracture fixation system according to claim 1 , wherein the first and second recesses define an arc segment in cross-section which extends over an angle (γ) with respect to the bore axis of the transverse bore and wherein the angle (γ) lies between 5° and 175°.

7. The femoral fracture fixation system according to claim 1 , wherein the first and second recesses define an arc segment in cross-section and wherein each recess has a width (wr) along the arc segment which lies between 1 mm and 10 mm.

8. The femoral fracture fixation system according to claim 1 , wherein the transverse bore defines a first diameter (d 1 ) which is oriented substantially parallel to a longitudinal axis of the proximal portion and a second diameter (d 2 ) which is oriented substantially perpendicular to a longitudinal axis of the proximal portion, wherein the second diameter (d 2 ) is greater than the first diameter (d 1 ) in at least a portion of the transverse bore.

9. The femoral fracture fixation system according to claim 1 , wherein the first and second recesses of the transverse bore are arranged adjacent to each other on opposite sides of the bore axis of the transverse bore.

10. The femoral fracture fixation system according to claim 1 , wherein the transverse bore has one of flattened and rounded edge portions in a region of at least one of the inlet opening and an outlet opening.

11. The femoral fracture fixation system according to claim 1 , wherein the transverse bore of the intramedullary nail bore axis is parallel to or coaxial with a longitudinal axis of the femoral screw.

12. The femoral fracture fixation system according to claim 1 , wherein the conical shape defines a taper with a cone angle with respect to the inner wall, wherein the cone angle lies within a plane including the bore axis.

13. A femoral fracture fixation system comprising:
a femoral intramedullary nail having a proximal portion, the proximal portion having a longitudinal axis and an outer surface extending generally parallel to the longitudinal axis;
a circular bore through the proximal portion outer surface extending at an angle to the longitudinal axis of the proximal portion, the proximal portion outer surface having recessed edge surface portions located on at least one side of the bore, the recessed edge surface portions comprising a flattened recessed edge surface portion and a rounded recessed edge surface portion at a screw or pin inlet end, the flattened recessed edge surface portion being flattened along a plane perpendicular to a plane containing both the longitudinal axis of the nail and a central axis of the bore and parallel to the longitudinal axis of the intramedullary nail proximal portion, and the rounded recessed edge surface portion being rounded around an axis transverse to the longitudinal axis and lying in a plane parallel to the plane of the flattened recessed edge surface portion, the circular bore further comprising an anterior and a posterior arc segment which extend into the bore from an opening on a lateral side of the intramedullary nail and tapers inwardly towards a bore axis of the circular bore;
a femoral screw slidably received within the circular bore, the femoral screw having a threaded portion for engaging a head of a femur; and
an anti-rotation element moveable along the longitudinal axis of the proximal portion of the nail, and selectively contacting an outer surface of the femoral screw to prevent rotation of the screw.

14. The femoral fracture fixation system as set forth in claim 13 wherein the anterior and posterior arc segments form surfaces of a cone.

15. A femoral fracture fixation system comprising:
a femoral intramedullary nail having a proximal portion, the proximal portion having a longitudinal axis and an outer surface extending generally parallel to the longitudinal axis;
a circular bore through the outer surface extending at an angle to the longitudinal axis of the proximal portion, the proximal portion outer surface having recessed edge surface portions located on at least one side of the bore, the recessed edge surface portions comprising a flattened recessed edge surface portion and a rounded recessed edge surface portion at a screw or pin inlet end, the flattened recessed edge surface portion being flattened along a plane perpendicular to a plane containing both the longitudinal axis of the nail and a central axis of the bore and parallel to the longitudinal axis of the intramedullary nail proximal portion, and the rounded recessed edge surface portion being rounded around an axis transverse to the longitudinal axis and lying in a plane parallel to the plane of the flattened recessed edge surface portion, the circular bore further comprising an anterior and a posterior arc segment which extend into the bore from an opening on a lateral side of the intramedullary nail and tapers inwardly towards a bore axis of the circular bore, wherein the arc segments taper towards the bore axis at an angle of between 1 and 10°;
a femoral screw slidably received within the circular bore, the femoral screw having a threaded portion for engaging a head of a femur; and
an anti-rotation element moveable along the longitudinal axis of the proximal portion of the nail, and selectively contacting an outer surface of the femoral screw to prevent rotation of the screw.

16. The femoral fracture fixation system as set forth in claim 15 wherein the anterior and posterior arc segments form surfaces of a cone.

17. The femoral fracture fixation system as

Assignees

• Stryker Europe Holdings I Llc

Inventors

• Simon Bernd
• Klüver Hendrik
• Paulsen Martje

Classifications

• A61B17/744

  the longitudinal elements coupled to an intramedullary nail · CPC title

• A61B17/88

  Osteosynthesis instruments;} Methods or means for implanting or extracting internal {or external} fixation devices {(A61B17/7074 takes precedence) · CPC title

• A61B17/7241

  the nail having separate elements through which screws pass · CPC title

• A61B2017/564

  Methods for bone or joint treatment · CPC title

• A61B17/72 Primary

  Intramedullary devices, e.g. pins or nails · CPC title