Comparison of low- versus high-intensity focused ultrasound in treating pain due to chronic soft tissue injury

Abstract

Objective To compare the low-intensity focused ultrasound (LIFU) and high-intensity focused ultrasound (HIFU) in treating pain due to chronic soft tissue injury. Methods Ninety-three patients with pain due to chronic soft tissue injury, aged 18-80 yr, with body mass index of 18-31 kg/m2, course of the disease 3 months-10 yr, and pain intensity of 4-8 in a numeric rating scale, were randomly divided into 2 groups using a random number table: low intensity group (group LI, n=49) and high intensity group (group HI, n=44). In group LI, the patients received LIFU with the minimum ultrasonic intensity causing senses (acid, hemp, swelling, pain), and the treatment was continued for 10 min.In group HI, the patients received HIFU with the focused ultrasound intensity that could not be tolerated by the patients, the treatment was continued for 1 min each time and then suspended for 1 min, and the total time for treatment was 10 min.The patients received the treatment once a day, and the course of treatment was 5 days in both groups.When numeric rating scale score > 4 during the treatment, parecoxib sodium 40 mg was injected intramuscularly as rescue analgesic.Both the therapeutic index and improvement in movement were used to evaluate the therapeutic effect, and the quality of life and depression were assessed and scored.The treatment-related adverse events were also recorded. Results The total effective rate was 98% and 84% in LI and HI groups, respectively.Compared with group HI, the total effective rate was significantly increased, the quality of life score was increased, and no significant change was found in depression score in group LI.No patients used parecoxib sodium or developed treatment-related adverse events in group LI.One patient (2%) required parecoxib sodium, the incidence of skin burns, nerve damage and abnormal pain was 4%, 2% and 2%, respectively, and no patients developed tissue swelling in group HI. Conclusion LIFU has higher therapeutic effect than HIFU in treating pain due to soft tissue injury, and the safety is good. Key words: Ultrasonic therapy; Soft tissue injuries; Pain