Patent ID: 6280442
Filing Date: 2001-08-28
Classification: A61B

Abstract:
A bone anchor assembly for engagement to an elongated member, comprising:a receiver member defining an upper opening portion and a lower opening portion each having respective minimum widths, a channel configured to receive the elongated member and communicating with said upper opening portion and said lower opening portion, and a groove around a portion of said lower opening portion;a crown member movably disposed in said lower opening portion, said crown member including an upper surface and a lower surface;a bone-engaging anchor having a lower portion configured to engage a bone and a head having a width, said width of said head being smaller than said minimum width of said lower opening portion, said head being movably disposed in said lower opening portion adjacent to said lower surface of said crown member; anda retaining member defining an aperture smaller than said width of said head, said retaining member at least partially housed in said groove of said receiver member and positioned around said anchor and below said head,wherein said retaining member prevents removal of said head from said lower opening portion.