Abstract: An implant device (100d) for engagement with a bone of a subject, said the implant device (100d) comprising a distal end (102d), a proximal end (104d), a central shaft (106d), a longitudinal central axis (108d) and a helical thread portion (110d) having a leading edge (114d) and a trailing edge (116d). A portion of the leading edge (114d) extends in a direction towards the distal end (102d) of the implant further than the most distal portion of the root (112d) of the thread portion (110d); and wherein the trailing edge (116d) extends in a direction of from the most proximal portion of the root (112d) in a radial outward direction and towards the distal end (102d); and a crest portion (118d) disposed between the leading edge (114d) and the trailing edge (116d) and wherein said the crest portion (118d) forms a radially outward portion of the thread portion (110d). Hence, the implant device (100d) improved the axial pull-out strength and reduced stress concentration.

Abstract: An implant device (100d) for engagement with a bone of a subject, said the implant device (100d) comprising a distal end (102d), a proximal end (104d), a central shaft (106d), a longitudinal central axis (108d) and a helical thread portion (110d) having a leading edge (114d) and a trailing edge (116d). A portion of the leading edge (114d) extends in a direction towards the distal end (102d) of the implant further than the most distal portion of the root (112d) of the thread portion (110d); and wherein the trailing edge (116d) extends in a direction of from the most proximal portion of the root (112d) in a radial outward direction and towards the distal end (102d); and a crest portion (118d) disposed between the leading edge (114d) and the trailing edge (116d) and wherein said the crest portion (118d) forms a radially outward portion of the thread portion (110d). Hence, the implant device (100d) improved the axial pull-out strength and reduced stress concentration.

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, 401L) that reacts to forces pushing the implant into bone tissue. The tip (12), ring (40) or insert (60, 62, 401L) 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, 401L) 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.

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, 401L) that reacts to forces pushing the implant into bone tissue. The tip (12), ring (40) or insert (60, 62, 401L) 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, 401L) 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.