A stem 100 for use in a joint prosthesis, such as a femoral stem for a hip joint prosthesis, comprises a solid central core 102, a proximal outer layer 127 over a proximal portion 101a of the core 102 and comprises longitudinal ribs 120 defining slots (130 fig. 3a) and a distal outer layer made of a deformable porous material over a distal portion 101b of the core 102. A distal end 106 may comprise a rounded or bullet shaped tip 108. The core 102 may be tapered. The proximal 127 and/or distal outer layers may have cylindrical or trapezoidal cross-sections. The ribs 120 may be disposed radially about the core 102 and may comprise a solid base (224 fig 7a) and an outer face (226 fig 7a) comprising a layer of porous material. There may be bone stimulating material, bone replacement material and/or bioactive bone substitute material within the slots (130 fig. 3a). The distal outer layer may comprise longitudinal ribs defining slots. There may be a fin (221 fig 5) and/or a collar 110. A method of manufacturing a stem 100 is also disclosed using additive manufacturing.
