Clinical Efficacy and Safety of Ultrasound-Guided Injection with Low-Molecular-Weight Peptides from Hydrolyzed Collagen in Patients with Partial Supraspinatus Tendon Tears: A Pilot Study

Background: This study evaluates the clinical efficacy and safety of two ultrasound (US)-guided injections of a 5 mg/1 mL low-molecular-weight peptide (LWP) solution derived from hydrolyzed bovine collagen in patients with supraspinatus partial tendon tears. Methods: A total of 21 patients with symptomatic partial tears of the supraspinatus tendon, detected by US, were consecutively enrolled and received one injection at a baseline visit (T0) and one after two weeks (T1). The primary outcome measure was the visual analogue scale (VAS) for pain. Secondary outcomes were the shoulder pain and disability index (SPADI) total score and the safety of LWP injections. Patients were examined at baseline (T0), at a week 2 follow-up visit (T1), and at a week 12 follow-up visit (T2). Results: A statistically significant improvement was found for both VAS pain and SPADI total scores, between T0 and T2 visits. US-guided injections were well tolerated and, apart from one patient with a progression of a tendon tear, no adverse events were recorded. Conclusions: Intratendinous tear US-guided injection therapy with an LWP solution was found to be safe and effective in improving both pain and shoulder function at a 12-week follow-up visit. The present pilot study should be considered the first step justifying a larger confirmatory investigation.