Calcific tendonitis is relatively common and often self-limiting. Treatment is usually conservative and involves cortisone injections, anti-inflammatory medications, and physical therapy. For patients with chronic calcification, surgical removal of deposits has been helpful. Gerdesmeyer and colleagues compared extracorporeal shock wave therapy (ESWT) with placebo treatment to determine whether ultrasonography treatment can be offered as an alternative to surgery.

Patients were randomized at seven centers to receive high-energy ESWT, low-energy ESWT, or sham treatment. Eligible patients were 18 years or older with at least six months of pain or tenderness from idiopathic type I or type II calcific tendonitis resistant to conservative treatment. They also had to have radiographic evidence of calcific deposits in the absence of rotator cuff tears and subacromial bursitis. Primary outcomes were a change in function and pain score at six months, with a 30 percent improvement defined as clinically relevant. Secondary end points were changes in mean three- and 12-month scores and in self-rated pain at three, six, and 12 months according to a visual analog scale, as well as interval radiographic assessment of presence and size of calcific deposits.

A total of 144 patients were treated, with 48 patients in each group. After six months, 10 patients were lost to follow-up, with greater numbers lost to follow-up after that. High-and low-energy treatments were superior to sham treatment after six months, with pain and function scores showing similar results. Scores at other intervals did not change this finding. Patients in the high-energy group had significantly less pain by visual analog score than patients in the low-energy group, and both groups had less pain than patients in the sham treatment group at six months.

At other intervals, the low-energy and sham groups were not statistically different in terms of the visual analog score. Radiographically, complete disappearance of the calcific deposit was observed in 60 and 86 percent of the high-energy group at six and 12 months, respectively. Complete disappearance of deposits was observed in 11 and 25 percent of the placebo group at six and 12 months, respectively.

The authors conclude that high- and low-energy ESWT has significant clinical benefit compared with sham treatment, and that high-energy ESWT is associated with significantly better outcomes. Because of high dropout rates, the data are more reliable at six months after treatment than at 12 months. ESWT may be a less expensive treatment for chronic calcific shoulder tendonitis than surgery.