Primary or revision, cemented or cementless, standard or lateralized The design rationale of the STEMSYS implant is based on the self-blocking concept. The cementless versions are made of titanium alloy and coated with either single hydroxyapatite layer or dual coating of porous titanium and hydroxyapatite. The cemented versions are made of high nitrogen content stainless steel and are fully polished. The cementless self-blocking concept has been validated by over 25 years of clinical use. The main characteristics are an immediate primary stability and a long term biological secondary fixation. STEMSYS is designed and manufactured in France, and includes the complete EVOLUTIS know-how in the industrial fileds of conception and manufacture of cementless femoral implants: more than 30.000 stems implanted since 2001 in France, Europe et in the world, with outstanding clinical results.