A method of measuring the relative position of a bone implant within a bone in a patient to detect movement between the implant and bone is provided, wherein one or more radiopaque bone markers have been implanted into the bone through a cannulated implant within the bone and one or more radiopaque implant markers have been implanted into the implant. The method comprises: i) determining a first relative position of the bone marker to the implant marker under a first parameter and ii) determining a second relative position of the bone marker to the implant marker under a second parameter, wherein a change in the position of the bone marker relative to the implant marker from the first relative position to the second relative position is indicative of movement of either the implant or the bone.
