Reduced stiffness femoral hip implant
US5336265A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1992 |
| Grant date | Aug 9, 1994 |
| Priority date | — |
| Expiry date | Nov 13, 2012 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F2310/00395
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A femoral component of an artificial hip joint includes an elongated stem with a single longitudinally extending, medially facing, groove in its outer surface intermediate its proximal and distal ends. The dimensions of the groove are chosen so as to obtain constant stiffness or, alternatively, a predetermined stiffness of the stem between the proximal and distal ends. In either event, the stem has a magnitude of stiffness no greater than that at which stress shielding of the first bone would occur. The groove and the outer surface of the stem intersect at an outer rim. The groove has a central concave surface and proximal and distal radiused end surfaces in communication with and blending smoothly with the central cylindrical concave surface. The groove is disposed at an angle within a range of 0.degree. to approximately 45.degree. relative to the coronal plane, extending in a lateral posterior to medial anterior direction. The component is preferably composed of titanium, titanium alloy, or cobalt-chromium alloy. The outer surface of the stem may be provided with a porous medium for encouraging bone ingrowth fixation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.