Aim. The first osseointegrated transfemoral amputation prosthesis operation was performed in Gothenburg in 1990. The aim is improving quality of life for patients who cannot use conventional socket prosthesis. In 1999 the prospective OPRA-study (Osseointegrated Prosthesis for Rehabiliation of Amputees) was initiated with standardized surgery, equipment and rehabilitation program. Method. The surgery consists of a two-stage procedure. At the primary surgery (S1), a titanium screw (the fixture) is inserted into the remaining diaphyseal bone. The fixture is 80 mm long with a diameter of 16–20 mm (+0.5 mm increments). The patient is hospitalized 5-7 days. At the secondary surgery (S2), six months later, an abutment is inserted into the fixture. The abutment has a hexagonal press-fitting into the fixture and is secured by an abutment screw. The patient remains hospitalized 10–12 days. Gradual increase of load and activity is initiated over a 6 month period. Results. The OPRA study includes 51 patients with 55 implants. Follow-up time has been set to minimum 2 years. The OPRA study will be evaluated in June 2010. 32 of the 51 patients have been followed for 2 years or more. Four implants have been removed due to loosening/infection. No patient has been lost to follow-up. Preliminary data shows that the success rate so far is 93% (51/55). Conclusion. Development of this new concept has to be carefully monitored and controlled. Once a standard technique was developed a drop in the complication rate was noted. Although deep infection and fixture loosening is the most feared complication, so far the most encountered one is late deformation of the abutment due to overload since the patients activity level is significantly increased caused by the good prosthetic function allowing the patient to use the prosthesis 12–15 hours daily, 7 days a week