Dynamic Roentgen stereophotogrammetry has proven valuable in the evaluation of fixation for hip and knee arthroplasty, as early RSA evaluations have shown high predictive value for later aseptic component loosening. In contrast, Dynamic RSA makes it possible to accurately assess both micro movements in the fixation interface and kinematics of the prosthetic components in three dimensions, during active motions. Dynamic Roentgen stereophotogrammetry Dynamic Roentgen stereophotogrammetry (also referred to as dynamic RSA) is a modern and sophisticated x-ray recording method, used to measure real-time 3D motions of prostheses and bones during motion with high accuracy. It is mostly used in orthopedic research settings and
Roentgen (unit) directive included the curie, rad, rem and roentgen as permissible units, but required that the use of the rad, rem and roentgen be reviewed before 31 December 1977. This document defined the roentgen as exactly 2.58 × 10 C/kg, as per the ICRU recommendation. Directive 80/181/EEC, published in December 1979, which replaced directive 71/354/EEC, explicitly catalogued the gray, becquerel and sievert for this purpose and required that the curie, rad, rem and roentgen be phased out by 31 December 1985. Today the roentgen is rarely used, and the International Committee for Weights and Measures (CIPM) never accepted the use of