An apparatus for the formation of a wire loop comprises a wire drive for advancing a wire and a loop layer to grip a first end of the wire and to lay a wire loop. When the wire is advanced, the wire loop is formed into a selected size. The apparatus also includes a pull-out gripper and a sensor device, the pull-out gripper being configured to grasp the wire of the wire loop and, after grasping the wire of the wire loop, move relative to the loop layer, thereby tensioning the wire loop in a longitudinal direction. The sensor device can detect a twist in the wire loop.