Orgel M, Liodakis E, Jaratjitwilai P, et al. - This research was sought to ascertain variations of cortical thickness in relation to the time after implantation of the Endo-Fix-Stem. Between 2007 and 2013, all transfemoral amputees treated by Endo-Exo-Prothesis were operated by the last author of this study. Researchers retrospectively examined x-ray images of 4 follow-up intervals (postoperative, 3 months, 12 months, 3 years). They classified femoral residuum into 3 sections (proximal, middle, distal) with 2 measuring points in each section: medial and lateral. Cortical thickness was assessed at these 6 points and correlated at regular intervals applying the Friedman test for non-parametric dependent variables. A total of 37 patients with 40 implants were enrolled in the study. Even whether the outcomes did not exhibit any significant difference, It can be deduced that the osseointegration process leads to a remodeling of the bone structure, both in terms of elevated bone formation and bone resorption. Nevertheless, it has not yet been conclusively clarified which processes lead to hyper- or atrophy. The outcomes suggest that force transmission between prosthesis and bone and the facultative bacterial colonization of the stoma are still the main factors which may be responsible for the bone remodeling processes.