Polyaxial bone anchor with non-pivotable retainer and pop-on shank, some with friction fit
US8556938B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Oct 5, 2010 |
| Grant date | Oct 15, 2013 |
| Priority date | — |
| Expiry date | Sep 19, 2031 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2090/037
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A polyaxial bone screw assembly includes a threaded shank body having an integral upper portion receivable in a receiver, the receiver having an upper channel for receiving a longitudinal connecting member and a lower cavity cooperating with a lower opening. The upper portion expands a retaining member in the receiver cavity to capture the shank upper portion in the receiver. In some embodiment either the retaining member or an insert provide for a friction fit of the shank upper portion in the receiver resulting in non-floppy placement of the shank with respect to the receiver. Some retainers and inserts have a lock-and-release feature. Final locking of the polyaxial mechanism is provided by frictional engagement between the shank upper portion and the retaining member. A pre-assembled receiver, retaining member and optional insert may be popped-on or snapped-on to the shank upper portion prior to or after implantation of the shank into a vertebra.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.