Prosthesis with resorbable collar

Abstract

An articulating hemiarthroplasty prosthesis (10) for use in arthroplasty is provided. The prosthesis includes a stem (12) for implantation at least partially within the medullary canal (14) of a long bone (16) and a collar (20). The collar (20) is operably associated with the stem (12) and extends outwardly therefrom. At least a portion of the collar (20) includes a resorbable material. The prosthesis includes a head (30) and a cup (46) for engagement with the head (30).

Description

CROSS REFERENCE TO U.S. PROVISIONAL PATENT APPLICATION [0001] This Application is a Utility Application based upon U.S. Provisional Patent Application Ser. No. 60 / 302,113 filed Jun. 30, 2001, entitled PROSTHESIS WITH RESORBABLE COLLAR.TECHNICAL FIELD OF THE INVENTION [0002] The present invention relates generally to the field of orthopaedics, and more particularly, to an implant for use in arthroplasty. BACKGROUND OF THE INVENTION [0003] This invention relates to implantable articles and methods for manufacturing such articles. More particularly, the invention relates to bone prosthesis and process for manufacturing the same. [0004] There are known to exist many designs for and methods for manufacturing implantable articles, such as bone prostheses. Such bone prostheses include components of artificial joints, such as elbows, hips, knees and shoulders. An important consideration in the design and manufacture of virtually any implantable bone prosthesis is that the bone prosthesis ha...

AI Technical Summary

Benefits of technology

[0030] Another technical advantage of the present invention is the ability to provide for an accurate initial and final stem position by utilizing the collar to position the stem against the resected portion of the bone. This is applicable to both cemented and uncemented stems, as well as to coated and uncoated stems, including those coated with a porous coating for bone ingrowth.

[0031] A further technical advantage of the present invention is the ability of the resorbed collar to alleviate stress shielding and resultant bone loss particularly to the medial calcar otherwise caused by a traditional metal collar.

Problems solved by technology

Collars are positioned on the resected end of the long bone and can potentially bear a considerable portion of the patient's weight.

Such load carrying of the collar can lead to stress shielding particularly at the proximal medial calcar portion of the resected long bone.

The stress shielding leads to bone resorption and bone loss.

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