A fixing device for holding a screw in a hole in a structure, said device having an axial passage to receive said screw, the device comprising: - an actuating part configured to engage with said screw when said screw is rotated in use; and - a plurality of arms extending from and hingedly connected to the actuating part, each arm comprising a distal portion, a connecting portion and an anchor portion, the connecting portion extending between the actuating part and the anchor portion and being hingedly connected to the anchor portion, and the anchor portion extending between the distal portion and the connecting portion and being hingedly connected to the distal portion, and wherein, in use, the screw extends through the axial passage and is rotated about its axis to engage with the actuating part, and after engagement of the screw with the actuating part, further rotation of the screw causes movement of the actuating part in a direction towards the distal portions to cause a part of each of the anchor portions to move in a radially outward direction with respect to the axial passage into an expanded configuration to anchor the fixing device in said hole, and in the expanded configuration at least a part of the actuating part is disposed between the anchor portions of the arms to resist or prevent radially inward movement of the anchor portions, wherein the actuating part comprises a contact surface and the anchor portion of each arm includes a prominence shaped to provide a bearing surface, said contact surface contacting the bearing surface to apply a force to the bearing surface, when the actuating part is moved in an axial direction towards the distal portions; characterised by the arms being in an insertion configuration formed or formable by moving the arms from an initial configuration in which the arms are splayed to the insertion configuration in which the arms are substantially aligned so that the distal portions define the axial passage; and said force has both an axial and a radial component and causes a proximal end of each of the anchor portions to start to move in a radially outwards direction as the actuating part is moved towards the distal portions by said further rotation of the screw. - an actuating part configured to engage with said screw when said screw is rotated in use; and - a plurality of arms extending from and hingedly connected to the actuating part, each arm comprising a distal portion, a connecting portion and an anchor portion, the connecting portion extending between the actuating part and the anchor portion and being hingedly connected to the anchor portion, and the anchor portion extending between the distal portion and the connecting portion and being hingedly connected to the distal portion, and wherein, in use, the screw extends through the axial passage and is rotated about its axis to engage with the actuating part, and after engagement of the screw with the actuating part, further rotation of the screw causes movement of the actuating part in a direction towards the distal portions to cause a part of each of the anchor portions to move in a radially outward direction with respect to the axial passage into an expanded configuration to anchor the fixing device in said hole, and in the expanded configuration at least a part of the actuating part is disposed between the anchor portions of the arms to resist or prevent radially inward movement of the anchor portions, wherein the actuating part comprises a contact surface and the anchor portion of each arm includes a prominence shaped to provide a bearing surface, said contact surface contacting the bearing surface to apply a force to the bearing surface, when the actuating part is moved in an axial direction towards the distal portions; characterised by the arms being in an insertion configuration formed or formable by moving the arms from an initial configuration in which the arms are splayed to the insertion configuration in which the arms are substantially aligned so that the distal portions define the axial passage; and said force has both an axial and a radial component and causes a proximal end of each of the anchor portions to start to move in a radially outwards direction as the actuating part is moved towards the distal portions by said further rotation of the screw.