 Concerning hemi-arthroplasty, two types of humeral prosthesis are usually used: anatomical stems or resurfacing head implants. Both provide good results. Nevertheless with these prostheses, patient can present with post-operative pains due to glenoid erosion, linked to the metallic compounds used in such a prostheses. To face this issue, it was decided to modify the metallic compounds, and in order to mimic the tribological properties of the cartilage, Pyrocarbon PyC was found to be the best material. 