BACKGROUND: Patellar tendinopathy (PT) is a major cause of morbidity in both high-level and recreational athletes. Whilst there is good evidence for the effectiveness of eccentric exercise regimens in its treatment, a large proportion of patients have disease which is refractory to such treatments. This has led to the development of novel techniques including platelet-rich plasma (PRP) injection, which aims to stimulate a normal healing response within the abnormal patellar tendon. However, little evidence exists at present to support its use.
PURPOSE:The aim of this systematic review was to determine the safety and effectiveness of PRP in the treatment of PT, and to quantify its effectiveness relative to other therapies for PT.
STUDY DESIGN: Systematic review.
METHODS: A systematic review was conducted in accordance with the PRISMA guidelines. A literature review was
conducted of the Medline, EMBASE and Cochrane databases, as well as trial registries. Both single-arm and
comparative studies were included. The outcomes of interest were pain (as measured by visual-analogue or
other, comparable scoring systems), functional scores and return to sport. Study quality and risk of bias were
assessed using the MINORS score (for non-randomised studies) and the Cochrane risk of bias tool.
RESULTS: Eleven studies fitted the inclusion criteria. Of these, two were randomised, controlled trials (RCTs), and one was a prospective, non-randomised cohort study. The remainder were single-arm case series. All noncomparative
studies demonstrated a significant improvement in pain and function following PRP injection.
Complications and adverse outcomes were rare. The results of the comparative studies were inconsistent and
superiority of PRP over control treatments could not be conclusively demonstrated.
CONCLUSION: PRP is a safe and promising therapy in the treatment of recalcitrant PT. However, its superiority over other
treatments such as physiotherapy remains unproven. Further RCTs are required to determine the relative
effectiveness of the many available treatments for PT, and to determine the subgroups of patients who stand
to gain the most from the use of these therapies
