High-energy shock-wave therapy may be effective for shoulder pain, function

High-energy extracorporeal shock-wave therapy (ESWT) is effective for improving pain and shoulder function in chronic calcific shoulder tendinitis and can result in complete resolution of calcifications, a meta-analysis found.

Researchers reviewed results from 28 randomized, controlled trials comparing high-energy (energy flux density ≥ 0.28 mJ/mm²) versus low-energy (energy flux density < 0.28 mJ/mm²) ESWT or placebo. Results appeared in the April 15 Annals of Internal Medicine.

The quality of trials varied in several respects and was generally low, with the number of patients ranging from 20 to 144 participants and trial durations ranging from 3 to 12 months. Six trials were double-blinded, 15 were single-blinded, and 7 did not report blinding. Withdrawal rates ranged from 0% to 33%, with 3 trials reporting a withdrawal rate of more than 20%. The trials had numerous sources of heterogeneity and bias, and 14 devices and a variety of regimens were used.

Compared with placebo, high-energy ESWT seemed to improve shoulder pain, function, and calcifications, whereas low-energy ESWT seemed to improve only function. The reduction in calcification was significantly greater after high-energy ESWT than after placebo treatment, while results for low-energy ESWT were inconclusive.

Eight calcific tendinitis trials directly compared high-energy ESWT with low-energy. For pain outcomes, the available studies did not demonstrate superiority of high-energy over low-energy ESWT. However, high-energy ESWT improved shoulder function significantly more than low-energy ESWT. High-energy ESWT seemed to be more efficient than low-energy ESWT in resolving shoulder calcium deposits.

The most commonly reported adverse events related to ESWT were petechiae, small bruises and hematomas, local erythema, and acute pain. Patients who received high- or medium-energy ESWT reported more adverse events than those who received low-energy ESWT or placebo. No serious adverse events occurred in any of the included studies.

The safety and efficacy of ESWT, coupled with its noninvasiveness, may suggest it as an alternative to surgery, the researchers concluded. “Extracorporeal shock-wave therapy is emerging as an innovative treatment for musculoskeletal disorders. As our understanding of its physiologic effects advance and more controlled homogeneous studies are conducted to further define the most effective dosing parameters and administration technique, ESWT may be a promising approach to treating chronic soft-tissue disorders,” they wrote.