Low-Intensity Pulsed Ultrasound Versus Sham in the Treatment of Operatively Managed Scaphoid Nonunions: The SNAPU Randomized Controlled Trial.

Update: This article was updated on September 4, 2024 because of a previous error, which was discovered after the preliminary version of the article was posted online. In the Note listing the members of the Wrist and Elbow Research Group of Canada, the text that had read "Thomas T. Goetz, MD, FRCSC" now reads "Thomas J. Goetz, MD, FRCSC".

Background: The primary goal after open reduction and internal fixation of an established scaphoid nonunion is to achieve union. Low-intensity pulsed ultrasound (LIPUS) has been reported to increase the rate of union and to decrease the time to union for multiple fractures and nonunions in clinical and animal models. The evidence for LIPUS in the treatment of scaphoid nonunion, however, is sparse. The aim of this study was to assess whether active LIPUS (relative to sham LIPUS) accelerates the time to union following surgery for scaphoid nonunion.

Methods: Adults with a scaphoid nonunion indicated for surgery were recruited for a multicenter, prospective, double-blinded randomized controlled trial. After surgery, patients self-administered activated or sham LIPUS units beginning at their first postoperative visit. The primary outcome was the time to union on serial computed tomography (CT) scans starting 6 to 8 weeks postoperatively. Secondary outcomes included patient-reported outcome measures, range of motion, and grip strength.

Results: A total of 142 subjects completed the study (69 in the active LIPUS group and 73 in the sham group). The average age was 27 years, and the cohort was 88% male. There was no difference in time to union (p = 0.854; hazard ratio, 0.965; 95% confidence interval, 0.663 to 1.405). Likewise, there were no differences between the active LIPUS and sham groups with respect to any of the secondary outcomes, except for wrist flexion at baseline (p = 0.008) and at final follow-up (p = 0.043).

Conclusions: Treatment with LIPUS had no effect on reducing time to union in patients who underwent surgical fixation of established scaphoid nonunions.

Level of evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.