56 patients with acute displaced diaphyseal fractures of the femur or tibia from a high-energy trauma were randomized to receive either extracorporeal shockwave therapy or no intervention (control) following open or closed reduction and internal or external fixation. The purpose of this study was to assess the efficacy of shockwave therapy as an adjunct treatment to promote bone healing through the evaluation of clinical outcomes and rate of nonunion at 1 year in comparison to a control group. The results demonstrated that pain, weight-bearing status, healing rate, and rate of nonunion were significantly improved in the extracorporeal shockwave therapy group when compared to the control group at 3, 6, and 12 months.