Method and apparatus for retaining screws in a plate

US7727266B2 · kind B2 · utility

Assignee

• Warsaw Orthopedic, Inc.

Inventors

• Gary S. Lindemann · Collierville, US
• Larry Gause · Memphis, US
• Robert A. Farris · Cordova, US
• Regis W. Haid, Jr. · Atlanta, US
• Stephen M. Papadopoulos · Paradise Valley, US
• Rick Sasso · Carmel, US
• Volker Sonntag · Phoenix, US
• Vince Traynelis · Iowa City, US
• Iain Kalfas · Beachwood, US

Key dates

• Filing date: Jun 17, 2004
• Grant date: Jun 1, 2010
• Expiry date: Dec 16, 2028

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B17/8047
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A retention system for maintaining a screw to a vertebral plate. One or more screws extend through apertures within the vertebral plate. A cavity is positioned adjacent to and overlaps into the aperture. A ring is positioned within the cavity and held in position by a cap. The cap attaches to the plate to prevent removal of the ring. The ring is deflectable between a first shape to allow the screw to be inserted and removed from the aperture, and a second shape to prevent screw back-out from the aperture. A method of using the system is also included and comprises positioning the ring within a cavity in the plate, maintaining the position of the ring to the plate by attaching a cap, inserting a screw through the aperture and attaching the plate to a vertebral member, and positioning the ring over the screw head and preventing the screw from backing-out.