PROBLEM TO BE SOLVED: To provide a dynamic bone anchor that is particularly suitable for a weak and/or osteoporotic bone or vertebrae.SOLUTION: A dynamic bone anchor comprises an anchor member which has a tubular body defining an anchor axis, and which has a plurality of barb elements. Each of the barb elements is moveable between a first position adjacent to a surface of the tubular body and a second position farther from the surface of the tubular body than the first position. At least a portion of a free cutting edge of the barb elements is inclined at an angle corresponding to a helical angle that extends for at least one full turn around the anchor axis. The anchor member is made at least partially of a first material that comprises a Ni--Ti based shape memory alloy. A longitudinal core member being at least partially provided in the tubular body and has a first portion that is not connected to the anchor member such that the anchor member is movable relative to the first portion, and a second portion that is connected to the anchor member.【課題】弱いおよび／または骨粗鬆症の骨または椎骨に特に好適な動的骨アンカーを提供する。【解決手段】アンカー軸を規定するチューブ体を有し、かつ複数のアゴ状素子を備えるアンカー部材を備え、各アゴ状素子は、チューブ体の表面に隣接する第１の位置と第１の位置よりもチューブ体の表面から離れた第２の位置との間で可動であり、アゴ状素子の自由刃先の少なくとも一部は、アンカー軸の周りを少なくとも完全に一回転分延びる螺旋角度に相当する角度で傾斜しており、アンカー部材は、Ｎｉ－Ｔｉ系形状記憶合金を含む第１の材料から少なくとも部分的になる。長手方向のコア部材は、チューブ体に少なくとも部分的に設けられ、アンカー部材がそれに相対的に可動であるようにアンカー部材に接続されていない第１の部分と、アンカー部材に接続される第２の部分とを有する。【選択図】図１
