Current state of systematic reviews for platelet-rich plasma use in knee osteoarthritis

Knee osteoarthritis (KOA) is a highly prevalent musculoskeletal disorder affecting millions of people. To date, there is no curative treatment for KOA other than joint arthroplasty. However, treatments such as platelet-rich plasma (PRP) have been proposed as a possible therapy, with increasing interest over the last decade. To date, there are no evidence-based guidelines in the use of PRP therapy for KOA, but there are numerous studies and systematic reviews (SRs) evaluating the usage of PRP in KOA. Since SRs are of great importance for clinical decision-making, it is necessary to access their methodological quality before any valid conclusions can be made. This study will evaluate the methodological quality of SRs on PRP therapy for KOA using a validated assessment tool known as AMSTAR 2, "A MeaSurement Tool to Assess systematic Reviews".

It is hypothesized that the methodological quality of SRs will be moderate, whereby most of the SRs will provide an accurate summary of the results but will include more than one critical weakness as defined by the AMSTAR 2 checklist.

The MEDLINE, EMBASE, PubMed and Cochrane databases were searched from inception to May 2023. Two independent reviewers selected SRs that investigated the use of injection therapies for KOA. Descriptive statistical analysis was performed. AMSTAR 2 assessment was completed independently by the same reviewers. Cohen's kappa was calculated to measure interrater reliability. The quality of the studies was rated as "high", "moderate", "low", and "critically low". The overall confidence assessment was tabulated.

Forty-one SRs were included in the analysis. The Cohen kappa was 0.88, indicating high interrater reliability. There were no "high" quality SRs identified. Seven SRs (17%) were of "low" quality, while the remainder (34 SRs, 83%) were rated as "critically low".

The methodological quality of the selected SRs was suboptimal. Clinicians should critically appraise the SRs and interpret their conclusions with caution before making clinical decisions. This study supports future work of high-quality SRs regarding the use of PRP injections for KOA.

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