What’s the best way to treat calcifying tendinitis of the shoulder that doesn’t respond to physical therapy, medications, or steroid injections? The authors of this systematic review report that the use of extracorporeal shockwave therapy (ESWT) has proven successful, though we still don’t know if it is the best treatment approach. That remains to be determined in future studies.
What is calcifying or calcific tendinitis? It’s a degenerative condition affecting the four tendons surrounding the shoulder called the rotator cuff. These include the supraspinatus, infraspinatus, teres minor, and subscapularis muscles. All four muscles can be affected, but usually it’s just one of the four. And the tendons are listed here in declining order of frequency (i.e., supraspinatus is affected most often and subscapularis least often).
Calcium crystals called calcium pyrophosphate are deposited in the tendons. No one knows where these crystals come from exactly. But once the tendons start to degenerate, the crystals are released into the soft tissues as the tendon fibrils break down. Research shows that the calcium crystals help the tendon degenerate. The tendons harden and symptoms of impingement can develop. With impingement, there is shoulder pain when the arm is raised overhead or to the side above shoulder level. The stiff tendon doesn’t move and glide as it should and it gets pinched between the bony structures of the shoulder. Sometimes the person with this problem can move the arm through the pain all the way overhead. But other people have limited motion that leads to decreased function.
By sorting through five years of data from recently published studies, researchers from the Department of Trauma and Orthopaedic Surgery in England were able to confirm that all studies showed improvement after treating calcifying tendinitis of the rotator cuff with extracorporeal shockwave therapy (ESWT). ESWT is the use of sound waves to create enough energy to disintegrate the calcium deposits. It has been used with good results for other problems like gallstones and kidney stones. Once the calcium crystals have been broken up, it appears that the body absorbs them because X-rays show they disappear.
Most of the studies included patients with Types I and II calcification. There are three types of calcifying tendinitis diagnosed by X-rays. Type I has deposits that have clear outlines. A line can be drawn around the dense deposits to show exactly where they are, their size, and their shape. Type II disease has a clear outline but tends to be spread out more through the tissue and harder to see as a distinct shape. Type III lesions look cloudy without a specific form, shape, or outline.
All studies used a scoring system called the Constant-Murley score to measure results before and after treatment. Having one test used by everyone made it possible to compare the outcomes from one study to the next — even when the studies weren’t all conducted exactly the same way. The authors point out that this advantage was also a disadvantage. With only one measure of results was used, it’s impossible to know if other test measures might have shown a different result (better or worse). They suggest that future studies use other scoring systems for a comparison.
But for now, it looks like extracorporeal shockwave therapy is safe and effective for this potentially disabling condition. Significant improvement in motion, pain, strength, and function was consistently reported in all studies included in the review. Improvements were reported using both high-energy and low-energy shockwave therapy but high-energy had the best results. Low-energy therapy was better than no treatment or sham (placebo) groups.