Helical Blade or Lag Screw? It Doesn’t Matter as Much as We Thought

Readers should welcome the robust, well-designed retrospective database study by Dr. Okike et al. on the topic of geriatric intertrochanteric femoral fractures treated with cephalomedullary nailing. The authors sought to determine whether the choice of cephalomedullary nail head element (helical blade or lag screw) affected aseptic revision rates. They found no difference in the overall rate of revision. They did find that the helical blade performed slightly better than the lag screw in healthier patients with a lower American Society of Anesthesiologist (ASA) classification (but more on this later). There have been multiple conflicting results published previously in the literature on this topic, which are well summarized in the discussion section and references of the article. Those prior studies were mostly small retrospective studies and meta-analyses. The study by Okike et al. was able to draw on the data of 22,308 procedures by hundreds of surgeons from 35 hospitals, which is its main strength. The large sample size can answer the question on revision rates definitively, and the large number of surgeons and centers adds a “real-world” component. For these reasons, I believe that this study is now the most definitive of the available studies on this topic. The main weakness of this study is that some important risk factors for revision, such as fracture pattern, reduction quality, and appropriate implant placement, were not considered in the analysis. Although this would be a major flaw in a smaller study, it is somewhat offset in this study by the large sample size. Such a large sample is likely to have a variety of fracture patterns, but I think that we can assume a typical distribution of them, especially since there would not have been a reason to select one implant over the other on the basis of the fracture pattern. And, while there may or may not have been some imperfect reductions, the overall failure rate of <2% tells us that the quality of surgery being performed was high. It is worth addressing the finding that, among patients with an ASA classification of 1 to 2, the helical blade was associated with fewer revisions than the lag screw. I think that this result needs to be interpreted very carefully. While the primary comparison contained >20,000 cases, a review of Table 3 shows us that there were 2,820 and 2,529 cases with ASA 1 to 2 in the helical blade and lag screw groups, respectively. The number of cases is much smaller than that in the overall study and may not be large enough to ensure that this finding was not a false-positive result. Finally, the overall difference identified was small: a <1% difference in revision rate between the groups. It is not clear whether such a difference is clinically meaningful. What should we take away from this study? I agree with the authors’ conclusion that “helical blade and lag screw fixation performed similarly overall.” In other words, the study tells us that the decision to use a lag screw or helical blade is not a particularly critical one and that they both can work fine and are reasonable to use. The authors have given us license to refocus our thoughts away from this topic and back to other areas, such as obtaining a quality reduction, placing the implants correctly, and dealing with problematic reverse-obliquity and comminuted patterns.