Abstract: A device for moving a first object relative to a second object, which device comprises a first part, which can be fixed to the first object, and a second part, which can be fixed to the second object. The first part comprises an elongated portion, along which the second part can move, which second part is provided with a clamping member, which is capable of clampingly engaging the elongated portion. The clamping member comprises shape memory metal, which gives the clamping member a clamping shape or a releasing (non-clamping) shape, depending on the temperature of the shape memory metal. The device may be suitable for being implanted into a human or animal body, whereby the first object is a first bone portion and the second object is a second bone portion, which bone portions are to be moved relative to each other.