Patent attributes
Various exemplary methods and devices are provided for fixing bone anchors to bone. In general, the methods and devices can allow for a bone anchor to be fixed to a bone at a desired angle to a receiver member. In an exemplary embodiment, a bone anchor assembly is provided that includes a bone anchor configured to engage bone, a receiver member that polyaxially seats a spherical head of the bone anchor, and a compression member seated within the receiver member, proximally of the head of the bone anchor. The compression member can have a distal end with gripping features thereon configured to create at least one line contact and/or one band contact with the head of the bone anchor, thus providing a firm grip on the head of the bone anchor and reducing a risk of slippage of the bone anchor with respect to the receiver member.