Patent · US Expired

Intervertebral spacer device

US5989291A · kind A · utility

453Cited by
6References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 26, 1998
Grant dateNov 23, 1999
Priority date
Expiry dateFeb 26, 2018

Classification

  • Technology area (CPC A)Human Necessities
  • CPC primaryA61F2310/00365
  • WIPO fieldMedical technology
  • WIPO sectorInstruments

Abstract

An intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated by at least one spring mechanism. The preferred spring mechanism is a belleville washer. In a first embodiment there are two belleville washers which are oriented in opposite directions such that the narrow ends thereof are in contact with each other and the wider ends are in contact with the respective end plates. In a second embodiment there is a single belleville washer which is modified to mount onto a ball-shaped head. The lower plate of this embodiment includes a post extending upwardly from the inner surface of the plate, the post including a ball-shaped head. The modified belleville washer is lockably mounted to the head such that the wider portion of the washer seats against the upper plate.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.