The use of platelet-rich plasma in studies with early knee
osteoarthritis versus advanced stages of the disease: a systematic
review and meta-analysis of 31 randomized clinical trials
Abstract
Purpose. Reports have concluded that platelet-rich plasma (PRP) is an
effective and safe biological approach to treating knee osteoarthritis
(OA). However, the efficacy of PRP in advanced stages of the disease is
not entirely clear. The purpose of this study was to evaluate whether
the use of PRP would be as effective in studies with early-moderate knee
OA patients compared to studies including patients with end-stage OA
based on the Kellgren-Lawrence classification. Methods. A comprehensive
search in MEDLINE, EMBASE, Scopus, and Web of Science was conducted to
identify randomized controlled trials (RCTs) comparing the effect of PRP
injections versus other intra-articular treatments on pain and
functionality. A meta-analysis was conducted using a random-effects
model and the generic inverse variance method. Results. We included 31
clinical trials that reported data of 2705 subjects. Meta-analysis
revealed an overall significant improvement of both pain (MD, -1.05
[95% CI -1.41 to -0.68]; I2 = 86%; P = < 0.00001) and
function (SMD, -0.99 [95% CI -1.34, to -0.65]; I2 = 94%; P =
< 0.00001), favoring PRP. Subanalysis for pain and functional
improvement showed significant pain relief in studies with 1-3 and 1-4
Kellgren-Lawrence OA stages, and a significant functional improvement in
studies with 1-2, 1-3, and 1-4 knee OA stages, favoring PRP. Conclusion.
Our results indicate that including patients with advanced knee OA does
not seem to affect the outcomes of clinical trials in which the efficacy
of PRP in knee OA is assessed.