Hugh D. Hestad,Jack A. Dant,Eric J. Lundequam,Eric P. Jerke,Deborah L. Hoch
申请号：
US13044174
公开号：
US08337530B2
申请日:
2011.03.09
申请国别(地区):
US
年份:
2012
代理人:
摘要：
A polyaxial bone anchor including a housing and a bone screw. A bottom surface of the housing includes an aperture that defines an angulation limit of the bone screw for each azimuthal angle around a longitudinal axis of the housing. The aperture is V-shaped, with the V-shape having converging side walls that define a low-angulation direction near their intersection and a high-angulation direction opposite the low-angulation direction. In some cases, the angulation limit of the bone screw is generally constant over a range of azimuthal angles centered around the high-angulation direction. The housing may be modular, including tabs on one component that are plastically deformed to engage a lip on another component. During assembly, a mandrel advances longitudinally along a bore in the housing, and forces the tabs radially outward toward the lip to a radially outward plastically deformed state.
