Outcomes of Treatment with Low-Intensity Pulsed Ultrasound After Opening Wedge High Tibial Osteotomy

Objective: We have retrospectively reviewed the outcomes of treatment with low-intensity pulsed ultrasound (LIPUS) in patients who underwent opening wedge high tibial osteotomy (OWHTO). Materials and Methods: Twenty-two knees of 20 patients, mean age of 64 years, were treated with LIPUS after OWHTO using artificial bone substitute. LIPUS treatment was performed in 7 knees with lateral cortical fracture, 11 knees with delayed union around artificial bone substitute, 3 knees with removal of plate and bone graft due to infection, and 1 knee with revision surgery due to breakage of plate. Duration of LIPUS treatment, standing femorotibial angle (FTA), and bone union were assessed. Results: Duration of LIPUS treatment was 131 ± 50 days in fracture group, 293 ± 88 days in delayed union group (P < 0.05). Standing FTA at pre- and post-treatment was 168.3 ± 3.1 and 168.4 ± 2.8 degrees in fracture group, and 168.3 ± 3.0 and 169.0 ± 3.0 degrees in delayed union group. There was no case with over 3 degrees of correction loss. Bone union was confirmed in all cases and plate was removed. Discussion: The findings suggested that LIPUS treatment was effective in patients after OWHTO. It should be elucidated whether LIPUS shortens the time to bone union around artificial bone substitute after OWHTO.