ASTM F1223 testing is designed to reveal the device’s characteristics that can influence a physician’s clinical decision making. Within ASTM F1223 guidelines, the testing methodology to be used to quantify total knee replacement constraint in adherence to motion delineation by the prosthetic’s articular design under loading conditions in an in vitro testing environment. ASTM F1223 tests geometrical design factors rather than causing deformation or introducing viscoelastic effects. Since this is not a wear test, the primary aim is to produce data and metrics suited for comparability to other devices.
Constraint describes the inability of a total knee replacement to displace further in a specific direction in a set of loading conditions and is the main focus in ASTM F1223 testing. Constraint determinations apply to mediolateral shear, rotary laxity, valgus-varus rotation, anteroposterior draw, and distraction. ASTM F1223 further specifies geometrical parameter identification of the prosthetic’s contacting surfaces that influence this motion.