Clinical Benefits and Safety of Polynucleotides Injections for the Treatment of Painful Tendinopathies: A Multicenter, Single-Cohort, Retrospective Study

Background: Tendons, along with joints, are among the most affected structures in musculoskeletal disorders. This multicenter, single-cohort, retrospective clinical study evaluated the clinical benefits of Polynucleotides (PNs) injections in reducing pain and improving functionality in patients with tendinopathies. Methods: This retrospective study included 68 patients with different tendinopathies, all diagnosed with persistent pain lasting at least six weeks, accompanied by functional impairment and swelling. Three periarticular/peritendinous injections of a PNs-based medical device were administered at T0 (baseline), FU-1 (two weeks post-T0), and FU-2 (four weeks post-T0), with efficacy and safety assessments at FU-1, FU-2, FU-3 (eight weeks post-FU-2), and FU-4 (24 weeks post-FU-2) groups. The primary outcome measure was pain reduction, assessed using a numerical rating scale (NRS). Secondary outcomes were the Clinical Global Impression–Improvement scale (CGI-I), and patient satisfaction using a 5-point Likert scale. Results: Longitudinal analysis showed an average NRS score reduction of -1.76±0.08 at each follow-up, with statistically significant reductions observed between each follow-up and the final one (FU-4). Based on the CGI-I scale, 78% of the clinicians rated the clinical condition of tendinopathies at FU-4 as "very much improved" or "much improved." Additionally, 88% of patients reported being "satisfied" or "very satisfied" with treatment at the final follow-up (FU-4). No adverse events were reported. Conclusions: As demonstrated by the positive outcomes reported in this study, PNs injections may offer a promising therapeutic option for the treatment of tendinopathies. This study may open up new frontiers for the implementation of conservative approaches in patients affected by tendinopathies.