Pulsed low-intensity ultrasound therapy for chronic lateral epicondylitis: a randomized controlled trial

Pulsed low-intensity ultrasound therapy (LIUS) has been found to be beneficial in accelerating fracture healing and has produced positive results in animal tendon repair. In the light of this we undertook a randomized, double-blind, placebo controlled trial to assess the effectiveness of LIUS vs placebo therapy daily for 12 weeks in patients with chronic lateral epicondylitis (LE).

Patients with LE of at least 6 weeks' duration were recruited from general practice, physiotherapy and rheumatology clinics, and had to have failed at least one first-line treatment including non steroidal anti-inflammatory drugs (NSAIDs) and corticosteroid injection. Participants were assigned either active LIUS or placebo. Treatment was self-administered daily for 20 min over a 12-week period. The primary end-point was a 50% improvement from baseline in elbow pain measured at 12 weeks using a patient-completed visual analogue scale.

Fifty-five subjects aged 18-80 were recruited over a 9-month period. In the active group 64% (16/25) achieved at least 50% improvement from baseline in elbow pain at 12 weeks compared with 57% (13/23) in the placebo group (difference of 7%; 95% confidence interval -20 to 35%). However, this was not statistically significant (chi(2) = 0.28, P = 0.60).

In this study LIUS was no more effective for a large treatment effect than placebo for recalcitrant LE. This is in keeping with other interventional studies for the condition.