Meta-analysis Comparing Autologous Blood-Derived Products (Including Platelet-Rich Plasma) Injection Versus Placebo in Patients With Achilles Tendinopathy.

PURPOSE: To compare the effectiveness of autologous blood-derived products (ABP) injection with that of placebo (sham injection, no injection, or physiotherapy alone) in patients with Achilles tendinopathy.

METHODS: Electronic databases, including PubMed, Scopus, EMBASE, and Cochrane Library were searched up to June 2017. All published or unpublished randomized controlled trials (RCTs) were included. Two independent raters assessed the risk of bias of RCTs with the Cochrane Risk of Bias Tool. The primary outcome was Victorian Institute of Sports Assessment-Achilles (VISA-A) score. Weighted mean differences (WMDs) were used for random effect meta-analysis.

RESULTS: Seven RCTs were enrolled in meta-analysis. The ABP injection and placebo revealed equal effectiveness in VISA-A score improvement at 4 to 6 weeks (short term, WMD 2.29, 95% confidence interval [CI]: -1.69, 6.27), 12 weeks (medium term, WMD 2.63, 95% CI: -1.72, 6.98), 24 weeks (long term, WMD 4.61, 95% CI: -1.25, 10.47), and 48 weeks (very long term, WMD 4.16, 95% CI: -6.82, 15.14). In meta-regression, there was no association between change in VISA-A score and duration of symptoms at 4 to 6 weeks (short term), 12 weeks (medium term), and 24 weeks (long term).

CONCLUSIONS: This meta-analysis revealed that ABP injection was not more effective than placebo (sham injection, no injection, or physiotherapy alone) in Achilles tendinopathy and that no association was found between therapeutic effects and duration of symptoms.

LEVEL OF EVIDENCE: Level I, meta-analysis of Level I studies.