IntroductionThe traditional treatment of calcifying tendinitis of the shoulder was based on many therapies: the use of analgesic and anti-inflammatory drugs, local steroid injections, lavage, needling, physiotherapy and surgical or arthroscopic removal have been proposed and applied. In fact, in the medical literature there are still conflicting suggestions about the management of this disease.Extracorporeal shock waves were first used in the 1980s for the treatment of urolithiasis. In the past few years they were introduced in orthopaedics for the treatment of tendon diseases such as enthesopathy, calcanear spur, tennis elbow and calcifying tendinitis of the shoulder. The results of extracorporeal shock wave therapy for chronic calcifying tendinitis of the shoulder are discordant in literature [1][2][3][4][5].Conventional shock waves are acoustic waves generated in water by an electrohydraulic, piezoelectric or electromagnetic sources. These waves are focused on a target point in the tissue by means of an acoustic lens or a reflector system. We used a radially expanded shock waves pneumatically generated with no need of focusing.On the basis of the experience accumulated in literature, we report the results of a prospective study about the effects of extracorporeal shock wave therapy (ESWT) in calcifying tendinitis of the shoulder, using a radial shock wave source. Abstract Over the past few years, extracorporeal shock wave therapy (ESWT) has been introduced for the treatment of some orthopedic diseases. The aim of this study was to assess the efficacy of ESWT on chronic calcifying tendinitis of the shoulder through a prospective study. We studied 30 patients (mean age, 56.6 years) with chronic calcifying tendinitis of the shoulder. The patients were treated for a mean of 6 sessions, with 1400 impulses for each session. We used the new device Electro Medical Systems-Swiss Dolorclast (Electro Medical Systems, Nyon, Switzerland), which emits radial expanded shock waves, pneumatically generated. Patients were evaluated before treatment and after a mean of 10 weeks on a patient-oriented questionnaire (Dawson shoulder questionnaire, validated Italian version) and by radiological and ultrasound examinations. Radiographic disintegration and partial resorption of the calcium deposit were respectively recorded in 50% and 30% of cases, and the ultrasound image showed modification of echogenicity in all cases. Clinically a good response to pain and to joint movement was recorded; the questionnaire also showed a statistically significant improvement. Shock wave therapy for calcifying tendinitis of the shoulder is effective from the patient's perspective and according to imaging outcomes. It could be considered an effective therapy for chronic calcifying tendinitis of the shoulder.