An interbody cage which comprises a cage body and a mobile rotational element which, when said mobile element is rotated around a longitudinal axis of the body of the cage, may engage one or both adjoining vertebrae and temporally distract the intervertebral space for easier insertion of the cage body. The rotational element may also be designed to durably engage the adjoining vertebrae after its rotation, so as to allow a durable increase of the distraction of the vertebrae. Methods of insertion of the interbody cage are provided wherein the vertebrae are first distracted by the insertion of the cage or of the mobile element, then further distracted by rotation of the mobile element, before the cage is fully inserted into the intervertebral space without the body's superior and inferior surfaces fully engaging the vertebrae in the process.