Advanced trial spacers, height measuring tool, and inserter and extractor handle
A trial humeral prosthesis may include a trial stem for implantation into a humerus, and a trial proximal body configured to couple to a trial articulating component. A plurality of trial spacers may be configured to couple the trial stem to the trial proximal body, the plurality of trial spacers including a first trial spacer and a second trial spacer. The first and second trial spacers may each include a proximal post and a tab extending radially outward from the proximal post, and a distal body having a larger outer diameter than an outer diameter of the proximal post, a slot being formed in the distal body. The slot of the distal body of the first trial spacer may be configured to receive the tab of the second trial spacer when the proximal post of the second trial spacer is received within the distal body of the first trial spacer.
1 . A trial humeral prosthesis comprising:
a trial stem configured for implantation into a humerus;
a trial proximal body configured to couple to a trial articulating component of the trial humeral prosthesis; and
a plurality of trial spacers configured to couple the trial stem to the trial proximal body, the plurality of trial spacers including a first trial spacer and a second trial spacer,
wherein the first and second trial spacers each include a proximal post, a divot, a shoulder adjacent to the proximal post, and a distal body having a prong extending distally therefrom, the prong including an interior protrusion, and
wherein the distal body of the first trial spacer is configured to receive the proximal post of the second trial spacer therein, and
wherein the first trial spacer is configured to be axially pushed onto the second trial spacer such that, when the first trial spacer is axially pushed onto the second trial spacer, the shoulder of the second trial spacer forces the prong of the first trial spacer to flex outwardly and, when the interior protrusion of the prong of the first trial spacer clears the shoulder of the second trial spacer, the prong of the first trial spacer snaps back so that the interior protrusion of the prong of the first trial spacer is received within the divot of the second trial spacer and is in abutment with the shoulder of the second trial spacer.
2 . The trial humeral prosthesis of claim 1 , wherein the first trial spacer has a height that is different than a height of the second trial spacer.
3 . The trial humeral prosthesis of claim 1 , wherein the proximal post of the second trial spacer includes two opposing flats, and an interior surface of the distal body of the first trial spacer includes two opposing flats, the two opposing flats of the proximal post of the second trial spacer being in contact with corresponding ones of the two opposing flats of the distal body of the first trial spacer when the proximal post of the second trial spacer is received within the distal body of the first trial spacer.
4 . The trial humeral prosthesis of claim 3 , further comprising a trial stem adaptor configured to be fastened to a proximal end of the trial stem by at least one screw.
5 . The trial humeral prosthesis of claim 4 , wherein the trial stem adaptor includes a distally-extending protrusion configured to mate with a corresponding proximal recess in the trial stem to prevent rotational movement of the trial stem adaptor relative to the trial stem.
6 . The trial humeral prosthesis of claim 4 , wherein the trial stem adaptor includes a proximal post, a divot, and a shoulder adjacent to the proximal post.
7 . The trial humeral prosthesis of claim 6 , wherein the proximal post of the trial stem adaptor includes two opposing flats, and an interior surface of the distal body of the second trial spacer includes two opposing flats, the two opposing flats of the trial stem adaptor being in contact with corresponding ones of the two opposing flats of the distal body of the second trial spacer when the proximal post of the trial stem adaptor is received within the distal body of the second trial spacer.
8 . The trial humeral prosthesis of claim 1 , wherein the distal body of the first trial spacer includes an interior surface defining a cavity that has a shape that corresponds to the proximal post of the second trial spacer.
9 . A humeral prosthesis system, comprising:
the trial humeral prosthesis of any of claims 1-7 ; and
a humeral prosthesis.
10 . The humeral prosthesis system of claim 9 , wherein the humeral prosthesis comprises:
a prosthetic humeral stem,
a prosthetic proximal body configured to couple to a prosthetic articulating component of the humeral prosthesis, and
a plurality of prosthetic spacers configured to couple the prosthetic humeral stem to the prosthetic proximal body, the plurality of prosthetic spacers including a first prosthetic spacer and a second prosthetic spacer.
11 . The humeral prosthesis system of claim 10 , wherein each of the trial spacers has a height that corresponds to a height of a corresponding one of the prosthetic spacers.
12 . The trial humeral prosthesis of claim 1 , wherein the shoulder is positioned distal relative to the proximal post such that the shoulder is positioned between the divot and the proximal post.