Abstract
There has been growing interest in recent years in the application of the principles of evidence-based medicine (EBM), although implementation is complex. Scientific, organisational, and behavioural factors all combine to shape clinical behaviour change. Case study based qualitative data are presented which illuminate such processes within one clinical setting (elective orthopaedics), drawn from a larger study. It is suggested that (1) there are alternative models of what constitutes "evidence" in use; (2) scientific knowledge is in part socially constructed; and (3) clinical professionals retain a monopoly of technical knowledge. The implication is that there may be severe obstacles to the rapid or broad implementation of EBM.