Regular readers of this section in Clinical Orthopaedics and Related Research® know that our editors use it to engage, often on controversial and complicated topics. This month, we offer a breather. No controversy. Just a solution to a common problem seen by all call-taking orthopaedic surgeons: Authors in this month's CORR® validate an easier and more practical way to classify a fracture that everyone sees when taking general orthopaedic surgery call 5. For as long as I’ve been practicing, surgeons have classified fractures of the 5th metatarsal using a well-known three-part system 4. But I’ve never been able to use it in a way that gives me confidence, and when others use it, I’m never quite sure whether to believe what I hear. More formal assessments have substantiated these concerns 2, 6, 8. This shouldn’t be very surprising. Two decades ago, a review 3 suggested that the number of unreliable classification schemes in our specialty far outnumbered the number of reliable ones, and with the proliferation of low-bar venues for publishing orthopaedic junk that has happened since then, this problem has only grown worse. CORR’s “Classifications in Brief” section has flagged unhelpful classification systems as such when appropriate, which seems like most of the time. Authors of a recent review in that section covering the familiar, widely used three-part classification system for these fractures 4 concluded that “none (of the validation studies) documented a level of interrater reliability that was sufficiently high for us to recommend the widespread use of this classification schema” 1. For this reason, the new two-part classification system published in this month’s CORR 5 is a breath of fresh air. It maps nicely onto generally agreed upon surgical decision-making and boasts an interobserver reliability kappa value over 0.9. This system arose from anatomic and biomechanical research one of the authors performed earlier 7, which identified a destabilizing impact of the peroneus brevis tendon insertion on the more distal fractures. The new classification is easy to use in practice, as making the call on these injuries involves answering but one simple question: Is the fracture within 15 mm of the tip of the metatarsal base? (If this sounds overly simplistic to you because feet come in different sizes, the authors have reassured us through Fig. 1 of their article 5 that these proximal fractures, which happen through an avulsion mechanism, always occur proximally to the medial inflection of the curve of the base of the fifth metatarsal, regardless of foot size.) The formal validation of this two-part classification system was robust 5, as it included a dozen participating surgeons of different experience levels and subspecialties from two institutions, none of whom had seen the images used in the earlier biomechanical study 7. The authors contend—sensibly, in my opinion—that the classification system is clinically useful, since proximal avulsion fractures would be expected to heal readily while those further away are more likely to have problems 5. Using this classification rubric should mitigate both worry and overtreatment, whether in the form of unnecessarily restricting patients’ activities, or worse—recommending unnecessary surgery. A good classification system facilitates communication, supports surgeons’ efforts to offer patients accurate prognoses, enables helpful research, and guides treatment. The system by Marcus and colleagues 5 seems like an across-the-board improvement in our ability to do all of those things for our patients with this very common injury. I look forward to future studies using it, which should be a great deal easier to have confidence in than those published up to this point. A thoughtful CORR Insights® commentary 9 that accompanies the article and makes some practical suggestions for implementation and future research directions is worth reading, as well.
Seth S. Leopold (Mon,) studied this question.