De Vil JJ, Van Seymortier P, Bongaerts W, De Roo PJ, Boone B, Verdonk R.  Scarf osteotomy for hallux valgus deformity:  a prospective study with 8 years of clinical and radiographic follow-up.  J Am Podiatr Med Assoc.  2010 Jan-Feb; 100(1): 35-40. (PubMed ID: 20093543)

WHY did the authors undertake this study?
There are literally hundreds of surgical procedures described for correction of the hallux abductovalgus (HAV) deformity and dozens of articles published on the scarf osteotomy.  This paper is unique in that it presents an 8-year follow-up of prospectively collected data.

HOW did they attempt to answer this question?
The primary outcome measures of the study  were radiographic measurements (hallux valgus angle, first intermetatarsal angle and sesamoid position) and AOFAS hallux scores collected pre-operatively and at 1-year and 8-years post-operatively. 

The authors’ specific surgical technique with single screw fixation is described in detail.  Inclusion criteria of the population cohort were patients >18 years of age who had failed conservative treatment and who presented with a severe HAV deformity (defined as a hallux valgus angle greater than 20˚). 

WHAT were the specific results?
Statistically significant differences were found  between all outcome measurements when comparing pre-operative values to the 1-year follow-up mark.  No significant differences were found between all outcome measurements when comparing 1-year post-operative values to 8-year post-operative values.

HOW did the authors interpret these results?
From these results, the authors concluded  that the scarf osteotomy offers effective, predictable and “sustainable” results for the correction of the HAV deformity.

Lopez-Vidriero E, Goulding KA, Simon DA, Sanchez M, Johnson DH.  The use of platelet-rich plasma in arthroscopy and sports medicine:  optimizing the healing environment.  Arthroscopy.  2010 Feb; 26(2): 269-78.

WHY did the authors undertake this study?
Using their own words, the authors correctly describe sports medicine as a field where “patients desire and require rapid recovery after injuries”.  Given the dramatically increased interest and use of platelet rich plasma (PRP) in the fields of sports medicine and arthroscopy, the authors endeavor to provide an in-depth review of the physiology and practicality of these interventions. 

HOW did they attempt to answer this question?
The authors begin by reviewing the normal physiologic mechanisms and processes of tissue healing following acute injury and chronic inflammation.  PRP preparations are able augment this physiology through the release of specific growth factors associated with concentrated platelets (in addition to other growth factors obtained from the plasma).  Interestingly, these preparations have also been demonstrated to produce anti-inflammatory, antibacterial and analgesic effects.

The specific characteristics of the different commercial protocols for PRP are also reviewed effectively.   The surgeon should consider the required blood volume, the final volume of PRP obtained, the final platelet concentration, the time of preparation and the specific platelet activator when comparing theses systems.

WHAT were the specific results?
Encouraging results within many different facets of arthroscopy and sports medicine have been obtained through systematic research including uses with tendon, ligament, muscle and cartilage.  Specific to the lower extremity, it’s use with Achilles tendon ruptures, Achilles tendinopathies, osteochondral defects, and osteochondritis dissecans have been described among others.

HOW did the authors interpret these results
The authors conclude their review by correctly pointing out that we require much more information with respect to specific indications, correct dosages and quantities, and the ideal time frame, but PRP has certainly “opened another therapeutic door” with respect to some of the pathologies we treat on a regular basis.

We’ve been hitting the statistics pretty hard over the last couple issues, so let’s take a step back and look at a relatively simple evaluation point of a paper about a surgical intervention.  The majority of publications in the foot and ankle literature specifically attempt to examine the “effect” of a single surgical intervention.  You have one group of patients, perform some type of surgery on them, and then hope to compare some variables before and after this intervention.  We talked about this exact situation in the last PJC issue with the article about sesamoid position.  We compared pre- and post-operative radiographic measurements after a single intervention (and found a common statistical mistake often made by authors with this type of study design).  The De Vil et al article from this issue also fits this design.  The authors are comparing radiographic measurements and AOFAS scores before and after a single surgical intervention (scarf osteotomy).

One very simple part of the critical analysis of these types of articles is to get a feel for the experience of the surgeon(s) participating in the study.  This entails looking at over what period of time it took for them to collect the cases.  The De Vil et al authors examined 23 consecutive surgeries over a time period of 3 months (August 1, 1999-October 31, 1999).   This means that the authors were performing this type of surgery approximately twice a week.  I think that most people would consider this to be a reasonable surgical volume.

But what if it had taken the authors 3 years instead of 3 months to collect this amount of patients?   Then they would have been performing this type of surgery at a rate of less than 1 per month.   While this wouldn’t mean that their data is invalidated or wrong, it would be a point of criticism that maybe these authors aren’t as experienced in this type of surgery, and may not be in an authoritative position to speak on it.

Although this is a fairly subjective portion of the critical analysis of the medical literature, I always attempt to get a “feel” for how often the specific surgery is being performed by the authors and compare it to my own practice.