Glenoid component for shoulder arthroplasty

1. A glenoid component, comprising:

a laterally facing bearing surface configured to engage a bearing surface of an element associated with a humerus; and

a stem portion extending medially away from the bearing surface, wherein the stem portion is configured such that when implanted in a scapula the stem portion includes

a first cross-section in an XY-plane perpendicular to an XZ-plane, wherein the XZ-plane is defined by an inferior tip of the scapula, a medial pole of the scapula where a spine intersects the scapula, and the center of the glenoid fossa,

a second cross-section parallel to the first cross-section and inferior to the first cross-section, and

a third cross-section parallel to the first cross-section and superior to the first cross-section, wherein

the first cross-section is shaped based upon a first triangle having a first length in the XY-plane along an X-axis defined by the medial pole of the scapula and the center of the glenoid fossa of the scapula,

the second cross-section is shaped based upon a second triangle having a second length along the X-axis,

the third cross-section is shaped based upon a third triangle having a third length along the X-axis, and

the first length is shorter than the second length and shorter than the third length.

2. The glenoid component of claim 1 , wherein the stem portion further comprises:

a fourth cross-section parallel to the first cross-section, inferior to the first cross-section, and superior to the second cross-section, and

a fifth cross-section parallel to the first cross-section, superior to the first cross-section, and inferior to the third cross-section, wherein

the fourth cross-section is shaped based upon a fourth triangle having a fourth length along the X-axis,

the fifth cross-section is shaped based upon a fifth triangle having a fifth length along the X-axis, and

the first length is shorter than the fourth length and shorter than the fifth length.

3. The glenoid component of claim 2 , wherein the third length is longer than the second length, the fourth length, and the fifth length.

4. The glenoid component of claim 3 , wherein the second length is longer than the fourth length, and the fifth length.

5. The glenoid component of claim 3 , wherein:

the first triangle defines a first area;

the second triangle defines a second area;

the third triangle defines a third area;

the fourth triangle defines a fourth area;

the fifth triangle defines a fifth area; and

the fifth area is larger than the first area, the second area, the third area, and the fourth area.

6. The glenoid component of claim 5 , wherein the second area is smaller than the first area, the third area, and the fourth area.

7. The glenoid component of claim 6 , wherein the fourth area is larger than the first area, and the third area.

8. A glenoid component, comprising:

a laterally facing bearing surface configured to engage a bearing surface of an element associated with a humerus; and

a stem portion extending medially away from the bearing surface, wherein the stem portion is configured such that when implanted in a scapula the stem portion includes

a first cross-section parallel to an XY-plane including an X-axis defined by a medial pole of the scapula and the center of a glenoid fossa of the scapula, the XY-plane perpendicular to an XZ-plane defined by an inferior tip of the scapula, the medial pole of the scapula where a spine intersects the scapula, and the center of the U glenoid fossa,

a second cross-section parallel to the first cross-section and inferior to the first cross-section, and

a third cross-section parallel to the first cross-section and superior to the first cross-section, wherein

the first cross-section is shaped based upon a first triangle having a first area,

the second cross-section is shaped based upon a second triangle having a second area,

the third cross-section is shaped based upon a third triangle having a third area, and

the first area is smaller than the second area and smaller than the third area.

9. The glenoid component of claim 8 , wherein the stem portion further comprises:

a fourth cross-section parallel to the first cross-section, inferior to the first cross-section, and inferior to the second cross-section, and

a fifth cross-section parallel to the first cross-section, superior to the first cross-section, and superior to the third cross-section, wherein

the fourth cross-section is shaped based upon a fourth triangle having a fourth area,

the fifth cross-section is shaped based upon a fifth triangle having a fifth area, and

the fifth area is larger than the fourth area and smaller than the first area.

10. The glenoid component of claim 9 , wherein:

the first triangle defines a first length along the X-axis;

the second triangle defines a second length along the X-axis;

the third triangle defines a third length along the X-axis;

the fourth triangle defines a fourth length along the X-axis;

the fifth triangle defines a fifth length along the X-axis; and

the first length is shorter than the second length, the third length, the fourth length, and the fifth length.

11. The glenoid component of claim 10 , wherein:

the fifth length is larger than the second length, and the third length; and

the fifth area is smaller than the first area, the second area, and the third area.

12. The glenoid component of claim 8 , wherein:

the first triangle defines a first length along the X-axis;

the second triangle defines a second length along the X-axis;

the third triangle defines a third length along the X-axis;

the third area is larger than the second area; and

the second length is longer than the third length.