Calcific tendonitis of the shoulder most commonly affects the supraspinatus tendon and may cause pain and decreased range of motion. Treatment includes anti-inflammatory drugs, percutaneous needle aspiration and surgery. Ultrasound therapy is frequently used for a number of painful musculoskeletal disorders, but clinical efficacy for most applications has not been evaluated. Ebenbichler and colleagues conducted a sham-controlled study to evaluate the efficacy of pulse ultrasound therapy for calcific tendonitis.

The randomized, double-blind study was conducted in Vienna, Austria, and included 54 patients (61 shoulders). The diagnosis of calcific tendonitis was based on radiographic and ultrasonographic evidence of calcific tendonitis. The diameter of the calcification had to exceed 5 mm, and all patients had to have pain or restricted range of motion in the affected shoulder for at least four weeks. Exclusion criteria were a prior history of shoulder surgery, a corticosteroid injection within the past three months or the regular use of analgesics or anti-inflammatory drugs.

Ultrasound therapy was administered five times per week for three weeks, followed by three times weekly for three weeks, for a total of 24 treatments. Each session lasted 15 minutes. The primary outcome of the study was a radiographic change in the calcium deposits at the end of the 24 treatments and at a nine-month follow-up visit. Secondary outcomes included an assessment of pain in the shoulder, active range of motion, strength of the shoulder and the patient's ability to perform activities of daily living. A pain score was also used to evaluate outcome.

The ultrasound therapy group included 32 shoulders, and the sham treatment group included 29 shoulders. The mean age of patients in the ultrasound group was 49 years and the mean age of those in the sham group was 54 years.

Radiologic evaluation of the ultrasound group revealed that the calcium deposits had resolved in six shoulders (19 percent) and had decreased by at least 50 percent in nine shoulders (28 percent). In the sham treatment group, calcium deposits did not resolve in any patient and decreased by at least 50 percent in three (10 percent) of the shoulders. At the nine-month follow-up evaluation, calcium deposits had resolved in 13 (42 percent) of the shoulders in the ultrasound treatment group. An additional seven shoulders (23 percent) were found to demonstrate improvement. In contrast, in the sham treatment group resolution occurred in two shoulders (8 percent) and improvement was noted in three shoulders (12 percent).

Clinical improvement was significantly more common in the ultrasound therapy group than in the sham treatment group. Twenty-nine shoulders (91 percent) in the ultrasound group demonstrated improvement, compared with 15 shoulders (52 percent) in the sham treatment group. The ultrasound group had a greater decrease in pain and more improvement in quality of life.

The authors conclude that ultrasound therapy is of definite benefit in patients with symptomatic calcific tendonitis. It helps eliminate the calcifications and provides at least short-term symptomatic relief. These findings are consistent with several other studies. The authors note that the way in which ultrasound stimulates resorption of calcium deposits is not known. It may increase blood flow and metabolism in the affected area, thus facilitating disintegration of calcium deposits.