Effectiveness of sub-acromial injections in rotator cuff injuries: A systematic review and meta-analysis

Sub-acromial injections are a therapeutic option for rotator cuff injuries; however, evidence regarding the most effective drug in this context is unclear, which needs to be investigated. To evaluate the effectiveness of various sub-acromial injections for rotator cuff injuries. We conducted a systematic review and pair-wise and network meta-analyses of randomized clinical trials (RCTs) comparing sub-acromial injections for rotator cuff injuries. The interventions evaluated were hyaluronic acid (HA), platelet-rich plasma (PRP), prolotherapy, and corticosteroids. The outcomes of interest were pain and functional improvement, which were evaluated with standardized scores. The Risk of Bias 2 tool and the Grading of Recommendations, Assessment, Development and Evaluation methodology were used to assess data quality. Twenty RCTs, comprising 1479 participants, were included. In the short term, HA achieved the best outcomes [pain mean difference (MD) = -1.48, 95% confidence interval (CI) -2.37 to -0.59; function MD = 10.18, 95%CI: 4.96-15.41]. In the medium term, HA, PRP, HA + PRP, and corticosteroids were not superior to placebo in improving pain. Based on function, HA + PRP was superior to placebo, corticosteroids, and PRP (MD = 26.72; 95%CI: 8.02-45.41). In the long term, HA, PRP, and corticosteroids were not superior to placebo in reducing pain. However, based on function, HA + PRP, PRP, and HA were superior to placebo, and HA + PRP had the best result (MD = 36.64; 95%CI: 31.66-33.62). HA provides satisfactory short-term results, while HA with PRP demonstrates functional improvement in the medium and long terms. However, no intervention maintained the pain-relief effect on > 3-month follow-up.