Jeng CL, Baumbach SF, Campbell J, Kalesan B, Myerson MS. Comparison of initial compression of the medial, lateral and posterior screws in an ankle fusion construct. Foot Ankle Int. 2011 Jan; 32(1): 71-76. (PubMed ID: 21288437)

WHY did the authors undertake this study?
Among the several factors that contribute to successful arthrodesis of the ankle joint, the type of fixation and generation of compression are routinely debated. The authors of this study undertook to analyze the standard three-screw configuration, specifically with respect to which of these screws generates the highest compression when inserted first.

HOW did they attempt to answer this question?
The primary outcome measures of the study were measurements of maximum pressure, absolute contact area and percent contact area of the ankle joint as measured with specialized pressure sensitive film. Eighteen cadaveric, unprepared ankle joints were analyzed with variable insertion orders of a 7.0mm partially threaded cannulated screw from standard medial, lateral and posterior approaches.

WHAT were the specific results?
No statistically significant differences were found with respect to pressure, absolute contact area, nor percent contact area between insertion of the three screws. Interestingly, they found an average percent contact area of only 11% with insertion of a single screw, and greater contact area observed anteriorly when compared to posteriorly.

HOW did the authors interpret these results?
From these results, the authors concluded that no formal recommendation could be made with respect to the insertion order of internal fixation when undertaking arthrodesis of the ankle joint with a three-screw configuration.

Shauver MS, Aravind MS, Chung KC. A qualitative study of recovery from type III-B and III-C tibial fractures. Ann Plast Surg. 2011 Jan; 66(1): 73-9. (Pubmed ID#: 20948418)

WHY did the authors undertake this study?
What an interesting analysis and study! Although reconstructive techniques have improved dramatically over the last several decades, Type III-B and III-C tibial fractures are known to result in low long-term physical, psychological and financial patient outcomes. Despite this, patients with these poor objective outcome measures seem to overwhelmingly report high subjective satisfaction with their outcome and care. The authors of this study aimed to examine this phenomenon with a qualitative analysis of patient experience following these injuries.

HOW did they attempt to answer this question?
This study was essentially without a primary outcome measure. The authors initially proposed that our typical objective outcome measures were unsuitable for analysis of patient subjective satisfaction. They instead utilized a technique known as "grounded theory" to guide the research where they began without a hypothesis and allowed a theory to emerge through the process of analyzing interview data.

WHAT were the specific results?
80% of participants were satisfied with their outcomes and treatment. Several "codes" emerged from the interviews, primarily focused on satisfaction, coping, and personal growth.

HOW did the authors interpret these results?
From these results the authors concluded that patients generally develop adaptive coping techniques that result in high levels of subjective satisfaction, regardless of poor functional outcomes. This is a really interesting read if you get tired on being buried by statistics during your journal reviews!

Let's take a closer look at the topic of the problems with evidence-based medicine. One of the most important concepts that I have ever learned came courtesy of an exercise physiology professor at the University of Florida who would always emphasize that a given study or experiment "never proves anything; it simply adds to the body of knowledge". There is no doubt that taking an evidence-based approach to medicine has more positives than negatives, but I think that we (as a profession) often don't do a good enough job recognizing the limitations of this approach.

I think that there are two major flaws with blindly accepting evidence-based principles. The first is the assumption that every question has an answer (and usually we assume that there is a single correct answer). The Jeng et al ankle arthrodesis article provides an excellent example of this. The authors initiated this study with a great clinical question: When considering the standard three-screw approach to ankle arthrodesis, which screw should I insert first to achieve maximal compression? It would easy to assume that the authors failed in their attempt to answer this question because they found equivalent results when individually inserting each screw. It's a little bit tougher to appreciate that finding no answer was just as important as finding a single answer.

There are some questions in which simply there isn't a single right answer, and I think it's important to realize this when treating patients. As physicians it is only natural that we always want to have not only an answer, but always have the single, best answer for our patients. We may be better served to instead recognize our limitations and do a better job of "surveying the field". Keep this in mind next time you're at a CME event listening to a lecture entitled "An Evidence-Based Approach to Topic X".

The second major flaw with evidence-based principles is that it assumes that we (as the medical community) are smart enough to know what that single right answer is. History is riddled with examples of how we are not as smart as we think we are. Thousands of years ago we knew from all available evidence that the Earth was the center of the universe. Hundreds of years ago we knew from all available evidence that illness came from an irregularity of the four humors. And decades ago we knew from all available evidence that the key to fixating ankle fractures was to realign the medial fracture and not worry about laterally. We know more today than we have ever known at any point in history, but it's nothing compared to what we will know tomorrow and the next day and the next day. Like my professor used to emphasize, a study will never prove anything; it simply adds to the ever-expanding body of knowledge from which we draw conclusions.