Combined ultrasound guided peritendinous hyaluronic acid (500-730 Kda) injection with extracorporeal shock waves therapy vs. extracorporeal shock waves therapy-only in the treatment of shoulder pain due to rotator cuff tendinopathy. A randomized clinical trial.

Background: Rotator cuff tendinopathy (RCTe) is the most common cause of pain and shoulder dysfunction. Numerous clinical studies have demonstrated the therapeutic capacity of exogenous peritendinous hyaluronic acid (HA), and the effectiveness of extracorporeal shockwaves therapy (ESWT) in reducing pain. The aim of this study was to evaluate the added effects of HA treatment plus ESWT (E-g) or ESWT alone (SC-g), focusing on reduction of self-reported pain and disability of patients with RCTe.

Methods: Monocentric, randomized open-label clinical trial. Patients' selection, enrollment and interventions were conducted at the Chiparo Physical Medicine and Rehabilitation outpatient facility (Lecce, Italy). Patients with a diagnosis of RCTe, were randomly allocated to the E-g or to the SC-g. Participants were assessed for self-perceived pain, and for disability, at baseline, after 30 and 60 days.

Results: Forty adults (mean age 50.8±6.3; 23 woman, 17 men) were enrolled in the study, twenty for each group. During the study, both groups improved their perceived level of disability of the arm (-25.01±2.79; P<0.001), and for pain (-3.13±0.50; P<0.001). A multiplicative effect was demonstrated in the time × treatment interaction for disability (beta±SE beta: 7.40±1.77; P<0.001), and pain (beta±SE beta: 0.95±0.32; P<0.001). Moreover, more patients in the E-g reached the MCID in the outcomes-score compared to SC-g. Lastly, number needed to treat were calculated, for disability: NNT=2 (95% CI: 1-3), and for pain-score: NNT=1 (95% CI: 1-2).

Conclusions: This study provides preliminary evidence that, compared to ESWT alone, the combining ESWT and peritendinous HA-injections, revert disability and reduces shoulder pain faster in patients with RCTe.