This essay examines Lorenz Böhler's modernist system of rationalized fracture care as a particular case of medical rationalization and standardization. Böhler's locally created culture of standardized practices is analyzed in the context of its concrete work environment but also situated in relation to aspects of its wider cultural environment. It will be described as part of a more general trend of body-based rationalization efforts in industry and health care, in which the machine metaphor was used to characterize both the body and the work process. The project's origins in World War I will be discussed, as well as its subsequent migration to a civilian setting and its resonance with postwar Viennese modernism, to which it contributed. The essay aims at contributing to a historically informed discussion of medical rationalization and standardization as a heterogeneous, value-laden, and historically contingent phenomenon.