Prosthetic femoral stem
US5152799A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 4, 1991 |
| Grant date | Oct 6, 1992 |
| Priority date | — |
| Expiry date | Oct 4, 2011 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F2250/0029
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A femoral stem prosthesis including a stem tapering from a proximal end to a distal end, and having a primary zone of taper and a secondary zone of taper. The secondary zone of taper, located at the distal end of the stem, has a larger angle of taper than that of the primary zone of taper, but substantially less than the taper in prior art stems. In the secondary zone of taper, the stem gradually tapers away from the femoral bone to avoid a sudden change in stress level in the bone at the distal stem tip, thus avoiding the incidence of thigh pain. The stem of the inventive prosthesis preferably includes longitudinal channels to increase its flexibility and preferably has a trapezoidal cross-sectional geometry to resist rotational forces and to provide multi-plane stability within the femur, thereby providing effective stress transfer to the femur.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.