Hip joint endoprosthesis with a stem to be anchored in the femur
US4645506A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 22, 1984 |
| Grant date | Feb 24, 1987 |
| Priority date | — |
| Expiry date | Jun 22, 2004 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F2/30734
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A hip joint endoprosthesis has a downward tapering stem (1) which is to be anchored in the femur and is composed of a main part (7) connected to the condyle head (4) and of a plurality of wedge pieces (10) which are movably guided longitudinally along the main part by means of cooperating guide surfaces (11,12). The friction on the guide surfaces between the main part (7) and the wedge pieces (10) is smaller than the friction caused by the outer surface (13), formed for promoting adhesion, of wedge pieces (10) on the bone. When the medullary cavity receiving the prosthesis stem widens, the load on the main part (7) causes an expansion of the wedge pieces (10) and hence an adaptation of the shape of the prosthesis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.