Systems for guided reaming of complex shapes
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.
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.