Dual taper stem extension for knee prosthesis

United States Patent m

Roberson, Jr.

[54] DUAL TAPER STEM EXTENSION FOR KNEE PROSTHESIS

[75] Inventor: Raymond H. Roberson, Jr., Bartlett, Term.

[73] Assignee: Smith & Nephew Richards Inc.,

Memphis, Term.

[21] Appl. No.: 206,515
[22] Filed: Mar. 4,1994

[51] Int. CI.6 A61F 2/38

[52] U.S. CI 623/20; 623/18; 623/22;

606/60

[58] Field of Search 623/18, 19, 20,

623/21, 22; 606/60, 62

[56] References Cited

U.S. PATENT DOCUMENTS

4,714,471 12/1987 Grundei 623/20

4,822,366 4/1989 Bolesky 623/20

4,936,853 6/1990 Fabian et al 623/20

4,985,037 1/1991 Petersen 623/20

5,002,581 3/1991 Paxson et al 623/23

5,061,271 10/1991 Van Zile 623/20

5,133,760 7/1992 Petersen et al 623/20

5,152,796 10/1992 Slamin 623/20

5,194,066 3/1993 Van Zile 623/20

5,282,865 2/1994 Dong 623/19

mi iti ii urn11 Iiiii in Iiiiiiii it i Iiiiimi

US005593449A [ii] Patent Number: 5,593,449 [45] Date of Patent: Jan. 14, 1997

5,286,260 2/1994 Bolesky et al 623/18

5,290,313 3/1994 Heldreth 623/20

5,358,526 10/1994 Tornier 623/18

FOREIGN PATENT DOCUMENTS 545833A1 11/1992 European Pat. Off. .

Primary Examiner—Paul B. Prebilic

Attorney, Agent, or Firm—Pravel, Hewitt, Kimball &

Krieger

[57] ABSTRACT

A knee prosthesis for surgical implantation to a patient's leg bone at the knee joint area includes a prothesis body portion that extends transversely relative to the patient's intramedullary canal for carrying a bearing surface that articulates with the patient's adjacent leg bone or with another prosthesis component. A conical connector extends from the prosthesis portion and along an axis that generally tracks the patient's intramedullary canal. A stem member includes first and second end portions and has a central longitudinal stem axis. The stem member includes a socket at each end portion for forming connections to the conical connector at the respective end portions as selected by the surgeon. One of the sockets has a central longitudinal axis that generally coincides with the central longitudinal axis of the stem. The other socket has a central longitudinal axis that forms an acute angle with the axis of the stem.

19 Claims, 3 Drawing Sheets