We thank M. McAlinden for his interest in our study. He questions the appropriateness of concluding that low-intensity pulsed ultrasound could decrease disability associated with nonunion of fractures, since the 3 studies we pooled did not specifically address this topic. We agree that firm conclusions about this cannot be made. However, in our results section, we made reference to a report that re-analyzed 2 of the pooled trials and found that tibial delayed union was significantly reduced (p = 0.02) in a subgroup of smokers vs. controls.1 We felt it appropriate to draw attention to this admittedly preliminary finding, given the importance that delayed unions (which may lead to non-unions) have in fracture healing. Of interest is a recent study that has added further support for the idea that therapeutic ultrasound has a potential role in the treatment of nonunited fractures.2
Jason W. Busse Mohit Bhandari Abhaya V. Kulkarni Department of Clinical Epidemiology and Biostatistics McMaster University Hamilton, Ont.