Implant pins useful for hip fracture repair are described. The pin (401) has tubular inner and outer elements (403,402) and is used for location and tensioning in combination with a reaction structure such as a metaphysis insert or hip plate (404). A setting compound such as bone cement can be injected through a channel (432) of the pin to form a set mass in the head of the femur. Avoid may be formed preliminarily in the acetabulum for this purpose. The end of the pin has an expandable formation (427) with a mechanism for expanding it in situ to become embedded in the set mass and provide a secure anchor. The application also describes novel types of metaphysis insert, and imaging methods and imaging apparatus useful in such surgery.
