Is there a role for low intensity pulsed ultrasound (LIPUS) in delayed or nonunion following arthrodesis in foot and ankle surgery?

•Foot and ankle arthrodesis will increase and nonunion will also increase.•LIPUS is a non invasive, cheap intervention to promote bony union.•The series describes 18 patients with confirmed non union treated with LIPUS.•12 patients (67%) were treated successfully with full union.•9/10 (90%) of small foot and ankle joints demonstrated a high incidence of union. Delayed union and nonunion following foot and ankle arthrodesis is a disabling complication for patients. There are no clinical studies looking at whether there is a role for use of low-intensity pulsed ultrasound (LIPUS) following this. The aim of this study is to investigate the efficacy of LIPUS in this cohort of patients in our centre. This was a retrospective observational study reviewing the use of LIPUS in patients who had arthrodesis of a number of different foot and ankle joints diagnosed with delayed or non-union. Over a 5year period, 18 patients (71st MTPJ fusion, 2 subtalar joints, 2 triple fusion, 4 ankle fusions and 3 isolated midfoot joint) with radiologically confirmed delayed union, were treated with a standardised LIPUS therapy. Twelve patients (67%) were treated successfully with full radiological union confirmed. 4 patients required further surgical revision surgery while 2 were treated conservatively. Isolated small foot joints demonstrated a higher incidence of fusion (9/10; 90%) after LIPUS in comparison to larger or multiple joint arthrodesis (3/8; 38%). There may be a role for the use of LIPUS as a treatment option in delayed union of isolated, small foot joint arthrodesis. However, we would not recommend its use in large or multiple F&A joint arthrodesis. Large multicentre series are required to confirm our findings.