Extract
The most sophisticated practice of evidence-based orthopaedics requires a clear delineation of relevant clinical questions, a thorough search of the literature relating to the questions, a critical appraisal of available evidence and its applicability to the clinical situation, and a balanced application of the conclusions to the clinical problem. The balanced application of the evidence (i.e., clinical decision-making) is the central point of practicing evidence-based medicine and involves an integration of our clinical expertise and judgment with patients' and societal values and with the best available research evidence.
The most sophisticated practice of evidence-based orthopaedics requires a clear delineation of relevant clinical questions, a thorough search of the literature relating to the questions, a critical appraisal of available evidence and its applicability to the clinical situation, and a balanced application of the conclusions to the clinical problem. The balanced application of the evidence (i.e., clinical decision-making) is the central point of practicing evidence-based medicine and involves an integration of our clinical expertise and judgment with patients' and societal values and with the best available research evidence.
While emphasis in orthopaedics is placed on the randomized trial as the optimal research design to evaluate a surgical intervention, randomized controlled trials are not always practical or feasible. At the time of this writing, almost 90% of the orthopaedic literature represents research findings from nonrandomized study designs, ranging from the more popular case series to prospective cohort studies1.
Studies in which randomization is not employed can be referred to as nonrandomized, or observational, study designs. There has been considerable debate about whether the results of nonrandomized studies are consistent with the results of randomized controlled trials2,3. Nonrandomized studies have been reported to both overestimate and underestimate treatment effects2,3. However, these findings have not been supported in two published papers that identified nonsignificant differences in results between randomized controlled trials and observational studies4,5.
Although surgeons may perceive that evidence-based medicine mandates a strict adherence to evidence from randomized trials, it more accurately involves informed and effective use of all types of evidence (from meta-analysis of randomized trials to the results reported in individual case series and case reports). This supplement highlights critical issues in the design, conduct, and interpretation of observational study designs in orthopaedic surgery. Using contributions from experienced surgeons and researchers, we provide both basic and advanced topics, with the primary objective of offering a balanced discussion that is relevant to the spectrum of clinical research experience of The Journal's readership. 
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