Bone anchor with locking cap and method of spinal fixation

US8221472B2 · kind B2 · utility

Assignee

• Synthes USA, LLC · US

Inventors

• Joseph Peterson · South Dartmouth, US
• Dennis Chien · West Chester, US
• Thomas Keyer · Irwin, US
• Edward J. McShane, III · Collegeville, US
• Joseph Capozzoli · West Chester, US
• Pascal Hauri · Sion, CH
• Scott Kramer · West Chester, US
• David Schindler · Lecanto, US

Key dates

• Filing date: Apr 25, 2006
• Grant date: Jul 17, 2012
• Expiry date: Apr 21, 2029

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B2017/681
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A bone anchor (100) for attaching a rod (108) to a bone has an anchor member (106) for attachment to the bone and an anchor head (104) having a U-shaped opening for receiving the rod. The bone anchor also includes a locking cap (102) that has a main body (900) and a set screw (1000). Advantageously, in one embodiment the locking cap preferably is designed such that a single tool can be used to lock the locking cap in place on the anchor body preferably with a 90° turn and preferably then drive the set screw to clamp the rod. The locking cap also preferably non-threadingly engages the anchor body. The anchor body preferably has an inclined surface on its top surface which elastically deflects extending tabs on the main body to secure the locking cap to the anchor body. A method of implantation and assembly of the bone anchor are also described.