Alignment guide for humeral or femoral stem replacement prostheses
The disclosure herein provides methods, systems, and devices for assisting alignment of humeral or femoral stems during replacement surgery. In one illustrative embodiment, a slotted disk is configured to position a prosthetic stem into a canal in the humerus when the stem is driven through the slot. In another illustrative embodiment, a similar slotted disk structure is configured to position a prosthetic stem into a canal in the femur.
1. An alignment guide for use with a prosthetic long bone replacement assembly, comprising:
a support having a peripheral edge at an outer circumference of the support, a superior face and an inferior face opposite the superior face, wherein the inferior face is configured to contact and fit on a bone cut surface of a long bone, wherein the peripheral edge of the support has a thickness defined by a distance from the superior face to the inferior face; and
an aperture within the support configured to guide a prosthetic stem through the aperture into a canal into an operative site,
wherein the prosthetic stem has an axis extending along a length of the prosthetic stem, wherein the aperture is bounded by sidewalls that define the aperture, the sidewalls having a thickness dimension that extends axially superior or inferior beyond the superior or inferior face of the support in a direction of the prosthetic stem axis,
wherein the thickness of the sidewalls is greater than the thickness of the peripheral edge of the support; and
a movable structure at the peripheral edge at the outer circumference of the support configured to allow the alignment guide to be disassociated from the prosthetic stem.
2. The alignment guide of claim 1 , wherein the aperture is defined by a sidewall configured to extend from the support.
3. The alignment guide of claim 1 , wherein at least one of the sidewalls is partially curved in order to guide the prosthetic stem into a curve of the canal in a long bone.
4. The alignment guide of claim 1 , wherein the support is configured to be stably placed at an angle to the bone cut surface of the long bone such that a prosthetic head of the prosthetic stem is optimally positioned on the long bone surface.
5. The alignment guide of claim 1 , wherein the support is configured to be stably placed flush to the bone cut surface of the long bone such that a prosthetic head of the prosthetic stem is optimally positioned on the long bone surface.
6. The alignment guide of claim 1 , wherein the support comprises a generally arcuate disc.
7. The alignment guide of claim 1 , wherein the support comprises a generally conical configuration.
8. The alignment guide of claim 1 , wherein the support comprises a generally box-like configuration.
9. The alignment guide of claim 1 , wherein the movable structure comprises a hinge.
10. The alignment guide of claim 1 , wherein the dimension of the sidewalls extending axially superior or inferior beyond the length of the peripheral edge of the support is at least 10%, 20%, 30%, 40%, 50%, 75%, or 100% of the length of the peripheral edge of the support.