Platelet-rich plasma intra-articular injections for haemophilic synovitis: Scientific knowledge does not support its use

No Benefit to Platelet-rich Plasma Over Placebo Injections in Terms of Pain or Function in Patients with Hemophilic Knee Arthritis: A Randomized Trial

BACKGROUND

Hemophilic knee arthritis is one of the most common presenting symptoms of hemophilia, and its management continues to be challenging to practitioners. Preliminary research has suggested that platelet-rich plasma (PRP) may have short-term efficacy in the treatment of hemophilic knee arthritis, but evidence for this treatment is limited.

QUESTIONS/PURPOSES

What is the effectiveness of PRP compared with placebo in (1) reducing pain and improving knee joint function (as measured by WOMAC, VAS, and Hemophilia Joint Health Score [HJHS]) and (2) improving quality of life (as measured by SF-36 scores) in patients with hemophilic knee arthritis through 24 months of follow-up?

METHODS

This was a prospective, parallel-group, double-blinded, single-center, placebo-controlled randomized clinical trial that included participants from a tertiary care center starting January 1, 2019, with follow-up completed on November 30, 2021. Participants were older than 18 years and had hemophilic knee arthritis confirmed by MRI, and they were randomly allocated to interventions in a 1:1 ratio. The investigators were not informed of the randomization sequence generated by the computer. Patient groups were comparable with respect to age, gender, BMI, hemophilia type, and disease severity at baseline. Physicians delivered three sessions (one per week) of a standard intraarticular injection of PRP (n = 95) or placebo (n = 95). The rate of successful blinding was balanced across the groups, which was assessed by asking participants which injection they thought they had received. The primary outcome was the WOMAC score (range 0 to 96; higher scores indicate more pain and worse function; minimum clinically important difference, 6.4 points) over 24 months. Among the 190 patients assigned to PRP or saline injections (mean age 31 ± 7 years), 100% (190) of patients were men). There was no between-group difference in the proportion of patients who completed the trial; 97% (92 of 95) of patients in the PRP group and 94% (89 of 95) of patients in the placebo group completed the trial. The most common adverse events were injection site discomfort 8% (8 of 95) in the PRP group and 4% (4 of 95) in the placebo group. An intention-to-treat analysis was planned, but there was no crossover between groups. All patients were included in the analyses. With 95 patients in each group, the study was powered a priori at 90% to detect a difference in WOMAC score of 6.4 points, which was considered a clinically important difference.

RESULTS

There were no clinically important differences in the mean WOMAC, VAS pain, HJHS, SF-36, and MRI scores between groups at any timepoint. Intraarticular PRP did not ameliorate function, symptoms, and quality of life in patients with hemophilic knee arthritis. At 24 months of follow-up, the mean difference between the PRP and placebo groups in the WOMAC score was -1 (95% CI -5 to 2; p = 0.42). The mean difference in the VAS pain score was -0.3 (95% CI -0.8 to 0.2; p = 0.19), in the HJHS was -0.6 (95% CI -1.4 to 0.1; p = 0.10), in the SF-36 physical component summary was 0 (95% CI -2 to 3; p = 0.87), and in the SF-36 mental component summary was -1 (95% CI -3 to 2; p = 0.64). The mean differences in the MRI scores of soft tissue and osteochondral subscore were 0.1 (95% CI -0.3 to 0.5; p = 0.59) and -0.3 (95% CI -0.7 to 0.1; p = 0.19), respectively.

CONCLUSION

Among patients with hemophilic knee arthritis, three intraarticular PRP injections, compared with placebo injections, did not improve hemophilic knee symptoms, function, and quality of life over 24 months. The results of this study do not support the use of PRP injections in patients who have hemophilic knee arthritis.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Inhibition of Fenton reaction is a novel mechanism to explain the therapeutic effect of intra-articular injection of PRP in patients with chronic haemophilic synovitis

INTRODUCTION AND AIM

Haemarthroses cause major morbidity in haemophilia resulting in chronic haemophilic synovitis (CHS) and arthropathy. Oxidation of haemoglobin-coupled iron released in synovium after haemolysis induces chondrocytes death and cartilage damage, allowing postulate using iron-chelating drugs as potential therapeutic tool for haemophilic joint damage. Considering that albumin, the most abundant plasma protein, is a physiologic iron chelator, we aim to demonstrate that impediment of haemoglobin oxidation is exerted by plasma as a mechanism involved in the therapeutic effect of intra-articular injection of platelet-rich plasma in CHS.

METHODS

Oxidation of haemoglobin (Hb) to methaemoglobin (MeHb) through Fenton reaction was induced in vitro by addition of potassium ferricyanide in the presence or absence of peripheral blood-derived platelets-rich or platelets-poor plasma (PRP/PPP) or albumin. The relevance of in vitro findings was analysed in synovial fluid (SF) samples from one patient with CHS obtained before and after 6 months of PRP intra-articular injection.

RESULTS

MeHb formation was completely impaired either by of PPP, PRP or albumin indicating that PRP exerts an anti-oxidative effect, probably due by plasma albumin. Analysis of SF samples revealed the presence of MeHb levels and haemosiderin-laden macrophages in SF obtained before PRP treatment. Reduction of synovial MeHb, normalization of cellular composition and improvement of health joint haemophilic score, pain and bleeding episodes were registered after 6 months of PRP intra-articular injection.

CONCLUSION

Inhibition of Fenton reaction and the consequent normalization of joint cellular composition is a noncanonical mechanism underlying the therapeutic effect of PRP intra-articular injection in CHS.

Haemophilic arthropathy: A narrative review on the use of intra-articular drugs for arthritis

INTRODUCTION

Intra-articular injections of various drugs are commonly used in patients with degenerative osteoarthritis and also in haemophilic patients. Haemophilic arthropathy is a particular type of secondary osteoarthritis (OA), but the degeneration of strong synovial, cartilaginous and subchondral constituents is provoked by the direct action of iron and blood in the joint.

AIM OF THE STUDY

The aim of this study is to review the literature regarding the use of various intra-articular drugs in joints affected by haemophilic arthropathy.

METHODS

We reviewed the data from the literature; the search was performed on three medical electronic databases (PubMed, Cochrane Library and Scopus Web of Science) by three authors (B. E., A. M. and V. N.) from 3 December 2018 till 15 December 2018. The search string was as follows: (hyaluronic acid OR viscosupplementation OR platelet-rich plasma OR corticosteroid OR mesenchymal stem cells) AND (haemophilia OR haemophilic arthropathy OR haemophilic arthritis).

RESULTS

Once the research was performed, a total of 300 articles were identified. 47 selected articles were analysed by the reviewers, and the eligibility of the study inclusion was assessed independently. Twelve papers were included based on clear fulfilment of the inclusion criteria. Thirty-five articles were excluded for the following reasons: no full text or accessible data for 14 of them, 15 involved surgery or rehabilitation therapy as the primary topic and 6 were systematic reviews (the main topics were beyond the haemophilic arthropathy).

CONCLUSION

Although the degree of scientific evidence of the publications on intra-articular injections of various drugs (hyaluronic acid, corticosteriods, PRP and MSCs) in haemophilia is very low, it seems that intra-articular injections of hyaluronic acid can relieve joint pain for months and can be repeated every 6-12 months, which is why they can be recommended. Corticosteroid injections seem to relieve joint pain for a few weeks, but their routine use is not recommended in haemophilia. The efficacy of PRP and MSCs in haemophilic arthropathy is pending confirmation, which is why they are not currently recommended.