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) In radiation protection the absorbed dose is the energy absorption which is an indication of likely acute tissue effects occurring at high dose rates, and from low levels of absorbed dose the equivalent dose, representing the stochastic health risk, can be calculated; for which the current SI units used are the gray (Gy) and the sievert (Sv) respectively. The roengten has been redefined over the years. It was last defined by the US National Institute of Standards and Technology (NIST) in 1998 as , with a recommendation that the definition be given in every document where the roentgen is used.