An elongate stem component of a femoral orthopaedic implant of a hip prosthesis, comprising: a metallic foam shell having a first elastic modulus, the metallic foam shell having an outer surface (60, 62) that engages a patient's bony anatomy, and comprising a sheath portion, and a metallic core which includes a neck, a proximal core segment, and a distal core segment which are arranged so that the proximal core segment is between the neck and the distal core segment, in which the proximal core segment can be positioned within the sheath portion of the shell with the neck protruding proximally from the sheath portion and the distal core segment extending from the distal end of the sheath portion, the core having a second elastic modulus which is greater than the first elastic modulus, in which when the orthopaedic prosthesis is viewed in a transverse plane extending through the sheath portion and the core, (i) a first thickness is defined between a medial-most point of the outer surface of the sheath portion and a medial-most point of a medial surface of the core, and (ii) a second thickness is defined between a lateral-most point of the outer surface of the sheath portion and a lateral-most point of a lateral surface of the core, the first thickness being less than the second thickness, characterised in that the foam shell includes a cover layer portion which is attached at its proximal end to the sheath portion and which extends away from the sheath portion towards the distal end of the shell, so as to engage the lateral surface of the distal core segment to the distal end of the core when the proximal core segment is positioned within the sheath portion, leaving the medial surface of the distal core segment exposed so that it can contact the patient's bone. a metallic foam shell having a first elastic modulus, the metallic foam shell having an outer surface (60, 62) that engages a patient's bony anatomy, and comprising a sheath portion, and a metallic core which includes a neck, a proximal core segment, and a distal core segment which are arranged so that the proximal core segment is between the neck and the distal core segment, in which the proximal core segment can be positioned within the sheath portion of the shell with the neck protruding proximally from the sheath portion and the distal core segment extending from the distal end of the sheath portion, the core having a second elastic modulus which is greater than the first elastic modulus, in which when the orthopaedic prosthesis is viewed in a transverse plane extending through the sheath portion and the core, (i) a first thickness is defined between a medial-most point of the outer surface of the sheath portion and a medial-most point of a medial surface of the core, and (ii) a second thickness is defined between a lateral-most point of the outer surface of the sheath portion and a lateral-most point of a lateral surface of the core, the first thickness being less than the second thickness, characterised in that the foam shell includes a cover layer portion which is attached at its proximal end to the sheath portion and which extends away from the sheath portion towards the distal end of the shell, so as to engage the lateral surface of the distal core segment to the distal end of the core when the proximal core segment is positioned within the sheath portion, leaving the medial surface of the distal core segment exposed so that it can contact the patient's bone.