Systems for guided reaming of complex shapes

Patent metadata

Field	Value
Publication number	US-12369930-B2
Application number	US-202318207458-A
Country	US
Kind code	B2
Filing date	Jun 8, 2023
Priority date	Jun 20, 2022
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

Systems and methods for reaming an intramedullary canal of a long bone comprise a trial stem configured to extend into the long bone along an insertion axis and a guide device comprising an adapter configured to couple to the trial stem and a reaming guidepost extending from the adapter along a guide axis, wherein the guide axis and the insertion axis are non-aligned. A method of reaming an intramedullary canal of a long bone to form a complex shaped socket can comprise inserting a stem into the intramedullary canal along an insertion axis, connecting a guide device to the stem, the guide device comprising a guidepost extending along a guide axis and guiding a cannulated reamer along the guidepost to remove bone from the intramedullary canal to form the complex shaped socket, wherein the guide axis and the insertion axis are non-aligned.

First claim

The claimed invention is:

1. A system for reaming an intramedullary canal of a long bone, the system comprising:
a trial stem configured to extend into the long bone along an insertion axis;
an angled stem extension comprising:
a shaft; and
a coupler configured to rotatably attach the shaft to the trial stem at an angle to the insertion axis;

a fastener for selectively locking rotation of the angled stem extension relative to the trial stem; and
a template device comprising:
a handle configured to slide over the angled stem extension; and
a template attached to the handle, the template having an outline of an implant to be inserted into the long bone.

2. The system of claim 1 , wherein the fastener axially couples the angled stem extension to the trial stem.

3. The system of claim 2 , wherein the fastener can be threadedly engaged with the trial stem to rotationally immobilize the angled stem extension.

4. The system of claim 1 , wherein the coupler includes a slot shaped to fit around a head of the fastener in a radial direction.

5. The system of claim 4 , wherein the shaft includes a first aperture to allow access to the head of the fastener.

6. The system of claim 1 , wherein the handle comprises:
a cannulated shaft;
a grip located at a proximal end of the shaft; and
a head located at a distal end of the shaft to which the template is attached.

7. The system of claim 6 , wherein the shaft of the handle comprises:
a second aperture configured to allow access to the fastener; and
a window configured to allow viewing of the angled stem extension within the cannulated shaft.

8. The system of claim 6 , wherein:
the grip extends perpendicular to the insertion axis; and
the template is connected to the head so as to extend in a plane perpendicular to the insertion axis when the template device is attached to the angled stem extension.

9. The system of claim 6 , wherein the template includes markers configured to indicate a tolerance band for a portion of the template to be placed at the anterior-most point of the long bone.

10. The system of claim 1 , further comprising a secondary reaming guide comprising:
a broach body configured to inserted into a bone pocket produced by a cannulated reamer sliding over the angled stem extension;
a first angled broach guidepost extending from the broach body; and
a second angled broach guidepost extending form the broach body;
wherein the first and second angled broach guideposts extend in medial-posterior and lateral-posterior directions relative to the insertion axis, respectively.

11. A method of reaming an intramedullary canal of a long bone to form a bone pocket, the method comprising:
providing a system comprising:
a trial stem configured to extend into the long bone along an insertion axis;
an angled stem extension comprising:
a shaft; and
a coupler configured to rotatably attach the shaft to the trial stem at an angle to the insertion axis;

a fastener for selectively locking rotation of the angled stem extension relative to the trial stem; and
a template device comprising:
a handle configured to slide over the angled stem extension; and
a template attached to the handle, the template having an outline of an implant to be inserted into the long bone;

inserting the trial stem into the intramedullary canal along an insertion axis;
orienting the angled stem extension relative to the trial stem;
attaching a template to the angled stem extension;
rotating the template along with the angled stem extension to align the template with anatomic features of the long bone;
locking a rotational position of the angled stem extension relative to the trial stem;
removing the template; and
reaming the intramedullary canal along the angled stem extension.

12. The method of claim 11 , wherein orienting the angled stem extension post relative to the stem comprises roughly aligning the angled stem extension toward a posterior side of the long bone.

13. The method of claim 11 , wherein rotating the template along with the angled stem extension to align the template with anatomic features of the long bone comprises positioning a perimeter of the template within an outer perimeter of the long bone.

14. The method of claim 11 , wherein attaching the template to the angled stem extension post further comprises:
sliding a shaft of a template handle over the angled stem extension, wherein the template is attached to an exterior of the shaft.

15. The method of claim 14 , wherein rotating the template along with the angled stem extension to align the template with anatomic features of the long bone comprises:
rotating a grip attached to the shaft to extend in the medial-lateral direction relative to the long bone.

16. The method of claim 11 , wherein reaming the intramedullary canal along the angled stem extension comprises sliding a cannulated reamer along the angled stem extension to form the bone pocket in the long bone.

17. The method of claim 16 , further comprising:
removing the trial stem along with the angled stem extension from the intramedullary canal;
inserting a secondary ream guide into the bone pocket; and
performing a secondary reaming operation using the secondary ream guide to modify the bone pocket.

18. The method of claim 17 , wherein performing the secondary reaming operation using the secondary ream guide comprises:
sliding a secondary reamer over a first guidepost of the secondary ream guide to widen the bone pocket in a medial direction; and
sliding the secondary reamer over a second guidepost of the secondary ream guide to widen the bone pocket in a lateral direction.

19. The method of claim 17 , wherein the secondary ream guide comprises:
a broach portion configured to broach the bone pocket; and
first and second secondary ream guideposts extending from the broach portion;
wherein the first and second secondary ream guideposts extend in medial-posterior and lateral-posterior directions relative to the insertion axis, respectively.

20. A system for reaming an intramedullary canal of a long bone, the system comprising:
a trial stem configured to extend into the long bone along an insertion axis;
an angled stem extension comprising:
a shaft; and
a coupler configured to rotatably attach the shaft to the trial stem at an angle to the insertion axis;

a fastener for selectively locking rotation of the angled stem extension relative to the trial stem; and
a secondary reaming guide comprising:
a broach body configured to inserted into a bone pocket produced by a cannulated reamer sliding over the angled stem extension;
a first angled broach guidepost extending from the broach body; and
a second angled broach guidepost extending form the broach body;
wherein the first and second angled broach guideposts extend in medial-posterior and lateral-posterior directions relative to the insertion axis, respectively.

Assignees

• Zimmer Inc

Inventors

• Yoko Tim
• Vandiepenbos Jeffery A
• Azbell Joseph Arthur

Classifications

• A61F2/4684

  Trial or dummy prostheses · CPC title

• A61B17/1668

  for the upper femur (A61B17/164 takes precedence) · CPC title

• A61F2002/30332

  Conically- or frustoconically-shaped protrusion and recess · CPC title

• A61F2002/3092

  having an open-celled or open-pored structure · CPC title

• A61F2002/30433

  using additional screws, bolts, dowels, rivets or washers e.g. connecting screws · CPC title