Patent ID: 7789901

Claim:
A bone anchor system for anchoring a support member to a bone having a hole formed therein and a cavity formed at a distal end of the hole, the bone anchor system comprising: a body having: (i) a shank that has a proximal portion and a distal portion adapted for insertion into the hole; (ii) a head formed on the proximal portion of the shank and having a support engagement portion adapted to secure the support member to the body; and (iii) a passage extending from an entry point formed at the proximal portion to an exit point formed in the distal portion; and an expandable member having a flexible wall disposed over the distal portion of the shank and at least partially enclosing an anchoring chamber containing the distal portion of the shank, and having an expanded state configured to conform to the cavity, wherein the anchoring chamber is in fluid communication with the exit point, whereby the expandable member is adapted to expand when a filler material is provided into the entry point, passes through the passage, passes out of the exit point, and into the anchoring chamber, and whereby upon filling the anchoring chamber with the filler material a portion of the expandable member conforms to the cavity and the body and the support member are substantially anchored to the bone, wherein the body is configured such that upon filling the anchoring chamber, at least a portion of the distal portion of the shank is embedded in the filler material.