Asymmetric hip stem

United States Patent im

Noble et al.

US005776204A

[li] Patent Number: [45] Date of Patent:

5,776,204 Jul. 7, 1998

[54] ASYMMETRIC HIP STEM

[75] Inventors: Philip C. NoWe. Houston, Tex.;

Anthony K. Hedley. Paradise Valley,
Ariz.; Michael J. Schulzki. Boonton;
William J. Kelly, Jr.. Clifton, both of
N.J.

[73] Assignee: Howmedica Inc.. New York. N.Y.

[21] Appl. No.: 653,295

[22] Filed: May 24,1996

[51] Int. CI.6 A61F 2/32

[52] U.S. CI 623/23

[58] Field of Search 623/18. 19, 23

[56] References Cited

FOREIGN PATENT DOCUMENTS

An improved asymmetric femoral hip stem component for use in cementless hip replacement procedures is described. The stem comprises a proximal region having a novel three-dimensional configuration to allow for better fit and stability of the stem within (he femoral intramedullary canal with minimal removal of strong bone therefrom. The stem further includes a twist isolated in the mid-stem region to improve lit while minimizing enlargement of the femoral canal. A distal end comprising a rotated internal slot is also described, wherein the slot reduces bending stiffness of the stem in both the coronal and sagittal planes.

14 Claims, 12 Drawing Sheets