A group of researchers from Sweden have conducted a prospective two-year case-control study to examine the outcome of percutaneous osseointegrated (OI) prostheses for patients with unilateral transfemoral amputations. The study cohort comprised 39 patients who were treated with the Integrum OPRA (Osseointegrated Prostheses for the Rehabilitation of Amputees) implant system. The patients had a mean age of 44 years; 23 had undergone a unilateral transfemoral amputation due to trauma, 11 due to a tumor, and five due to other causes. At baseline, 33 used socket-suspended prostheses. The outcome measures used included the Questionnaire for Individuals with Transfemoral Amputation (Q-TFA), SF-36 Physical Function (PF) and Physical Component Scores (PCS), SF-6D health survey, and the Physiological Cost Index (PCI).