The authors of this study report a definite benefit to shock wave therapy in the conservative (nonoperative) treatment of calcific (calcifying) tendinitis of the shoulder. That’s good news because this condition can affect up to 20 per cent of the adult population. And calcific tendinitis can cause debilitating shoulder pain — even leading to a frozen shoulder.
Calcific tendinitis is a disorder characterized by deposits of hydroxyapatite (a crystalline calcium phosphate) in any tendon of the body. Some people just refer to this as calcium deposits in the shoulder. The calcific deposits can be seen on X-ray as lumps or cloudy areas. That’s how the diagnosis is confirmed.
The tendons of the rotator cuff surrounding the shoulder are affected most often. Pain and inflammation result in loss of motion and function. Sometimes patients report shoulder stiffness or weakness. There may be a snapping or catching sensation during certain shoulder movements.
Treatment begins with antiinflammatories, steroid injections, and/or physical therapy. The condition is often self-limiting meaning it goes away or resolves on its own in time. Most patients are encouraged to stick with the treatment plan for six months. If, after six months, the pain isn’t reduced enough (or at all), then shock wave therapy called extracorporeal shock wave therapy (ECSW) may be considered. ECSW may be a good next step before thinking about surgery.
ECSW uses sound waves directed at the deposit. No one knows for sure how this works but it does seem to bring pain relief and the calcific deposit disappears on X-rays. It appears that the mass is broken up enough by the vibration of the sound waves that the body can then breakdown, liquefy, and absorb or resorb the fragments.
But there are many questions left hanging about this treatment. Who does it help? Is it safe and effective for everyone? What dose (pulses per session or number of sessions) gives the best results? Should high- or low- energy be used? Does it even matter?
By conducting a meta-analysis, the authors were able to answer two questions: 1) is it safe and effective? and 2) does the dose (high-versus-low) make a difference? A meta-analysis is done by reviewing all publications reporting on controlled trials of ECSW for calcific tendinitis of the shoulder.
Some studies compared patients who had ECSW with those who received no therapy, some other type of treatment, or a sham or placebo treatment. Sham or placebo means they thought they were getting the treatment but no sound waves were actually transmitted to the calcium deposits. There were also trials comparing shock wave therapy of different energy levels.
After comparing and analyzing all the data, they found that shock wave therapy was more effective than sham treatments or other therapy such as electrical stimulation. High-energy waves (0.2 mJ/mm2 or higher) worked faster and better in terms of pain reduction and calcium resorption.
Patients experienced a decrease in pain and improved function. And it appears that using high-energy shock waves was more important than the number of sessions. X-rays showed proof that the calcium deposits were disappearing.
It’s still not clear if patient selection is an important factor in the use of ECSW for calcific tendinitis of the shoulder. Future studies are needed to look into this variable as well as define the number of sessions needed for the fastest, most effective treatment of this condition. For now, it’s clear that ECSW is a safe and effective way to treat calcium deposits in the rotator cuff tendons. And it may help patients avoid having surgery.