Polyaxial screw for acetabular cup
US7316715B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 18, 2005 |
| Grant date | Jan 8, 2008 |
| Priority date | — |
| Expiry date | Feb 18, 2025 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F2230/0021
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The invention relates to a device which is used for solidly connecting an acetabular cup shell to bone using at least one screw. According to the invention, the screw passes through a hole housing a ring mounted in the shell of the acetabular cup. The ring is mounted within an aperture of the shell and can be rotated therein about the longitudinal axis of the screw. The ring is a split-ring comprising a non-circular outer profile which co-operates with the non-circular profile of the hole which is disposed in the shell. In this way, when the ring is rotated in the hole and wedged in place therein, it is constricted thereby locking the screw to the shell in the desired position. Alternately the screw can have an enlarged thread adjacent it's head end to expand an internally threaded split-ring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.