The persistent clinical uncertainty that characterizes medical innovation provides important insights beyond the health arena and for the broader framework of evolutionary approaches to technological change. This paper focuses on the intimate connection between uncertainty and the process of hybridization, defined as the embodiment of multiple competing operational principles within a single device. We argue this type of solution and the associated problem solving emerge as a response to persistent clinical uncertainty about the performance of competing operational principles. Stated in conditional programming language, hybridization corresponds to “if you do not know which one is better then choose all”.The history of the intervertebral artificial disc, a surgical prosthesis used in the treatment of spinal pain, offers important insights into the hybridization of technologies under persistent uncertainty. The paper presents the case of the only hybrid artificial disc that has been approved for use in regular clinical practice.