| abstract |
A device for engagement with a bone includes a dynamically expandable tip ( 12 ), a dynamically expandable ring ( 40 ), or other dynamically expandable insert ( 60, 62, 401 L) that reacts to forces pushing the implant into bone tissue. The tip ( 12 ), ring ( 40 ) or insert ( 60, 62, 401 L) expands at least normal to the direction of motion, increasing contact area between the surrounding bone tissue and the material and thereby reducing the occurrence of high areas of contact stress in the adjacent bone tissue. The tip ( 12 ), ring ( 40 ) or insert ( 60, 62, 401 L) translates forces along an axis of motion into lateral frictional forces that can resist penetration into the bone tissue without the need for additional operator or patient interaction. A method of reducing migration of the device for engagement includes the steps of providing the device and inserting the device within bone tissue. |