There is increasing recognition that major new medical therapies should
be rigorously evaluated before they are put into general clinical use.
Randomized controlled trials provide the most unbiased assessment of the
risks and benefits of such therapies. In this article, the most important
aspects of the design and execution of a randomized clinical trial in
orthopaedics are discussed. These include the reasons for and mechanisms of
randomization, appropriate selection of patients and therapy, reasons for
the blinding of therapy, types of measures of outcome that can be used,
aspects of sample-size calculation and analysis of data, and ethics of
randomized controlled trials.