A femoral instrument for use in the intramedullary canal is described and includes an intramedullary rod having a tip at a free end. A body is attached to the intramedullary rod and has a face with a bone abutting portion. A centralizer mechanism is located within the rod and is operable to deploy and retract a plurality of members to engage and disengage an inner surface of the intramedullary canal. The length of the intramedullary rod from the tip to the face of the body is less than 30 cm. The instrument can also include an angular adjustment mechanism. The angular adjustment mechanism can have a plurality of formations and can be rotated about the longitudinal axis of the intramedullary rod to present at least a one of the formations to abut a portion of the body to define the relative angle between the body and the intramedullary rod.