Bone attachment device for use with tissue grafts and membranes

An attachment device for retaining tissue and synthetic membranes to a bone graft site comprising:

• an elongated cylindrical body member extending along a longitudinal axis from a first end to a second, opposite end with reference to a selected direction taken along the longitudinal axis, the first end formed with a pin point tapering up to a first diameter forming a first axial length portion, a second axial length portion extending from the first axial length portion and increasing in diameter at a given angle with respect to the selected direction to a second diameter, a third axial length portion forming a tapered locking flange increasing diameter at a greater angle with respect to the selected direction then the given angle, the locking flange extending from the second diameter to a third diameter having a third axial length and having a locking surface extending around the periphery generally perpendicular to the longitudinal axis at the third diameter extending radially inwardly to a fourth axial length portion having a fourth diameter extending from the third axial length portion and an additional axial length portion having a self-tapping thread and a relatively enlarged tissue and membrane retaining head formed at the second end, the head having a step portion having a selected diameter greater than the fourth diameter and less than the diameter of the head and having a selected axial length to inhibit bone growth over the head.