In my previous blog I reviewed the excellent RESTORE study1, which concluded no benefit for platelet-rich plasma (PRP) over saline injection for knee osteoarthritis (OA) (according to the authors) and which no doubt will be used to justify exclusion of funding for PRP injections, despite previous reviews showing likely benefit2-6. Even though knee OA has very few evidence-based treatments, mainstream medicine groups don’t want to consider PRP as a treatment and RESTORE will be used (justifiably, to an extent, as the results were disappointing) to continue freezing out PRP from funding within medical systems7.
Don’t @ me, but PRP is better than cortisone
If you want any further evidence that there is a cultural war going on, look no further than the response of mainstream medicine to the McAlindon 2017 JAMA study8. This study showed far more dismal results for corticosteroid injections than the RESTORE study showed for PRP. There was no clinical benefit to corticosteroid (in fact unlike PRP it did worse than saline) and you also got significantly more cartilage degeneration to go with the lack of any clinical benefit. In response to McAlindon, we’ve heard “crickets” from medicine’s ruling class. Corticosteroid injections are still recommended by guidelines published subsequent to McAlindon9 10, still funded almost everywhere, and still by far the most common injection type. If you can’t afford to privately pay for exercise treatment, or PRP injections (both of which are not generously funded by health systems), you will get offered “free” corticosteroid injections under most medical systems. Even though the results for corticosteroid injections are clearly worse than PRP and exercise.
There are some 8 RCTs directly comparing PRP to corticosteroid and – surprise surprise – they favour PRP individually (e.g. 11 12) and when entered into a meta-analysis13. But culture war will ensure that – for a while yet – the darling treatments of mainstream medicine – knee arthroscopy, NSAIDs, opiates and corticosteroid injections (my “four horsemen of the knee apocalypse”, Table 1), will continue to get funded by most medical systems around the world.
The four horsemen of the knee apocalypse
The harmful four of knee arthroscopy, NSAIDs, opiates and corticosteroid injections all are harmful in slightly different ways, as I outline in Table 1. And I accept that individually there can be circumstances for each of the four where they are justified, but don’t accept that they are so commonly used in situations where risks outweigh the benefits. Yes Table 1 is not peer reviewed – but my response is that Table 1 is based on published studies. It might not pass peer review because of “culture wars”. Also, I don’t include all knee OA treatments in Table 1 – hyaluronan gel is another similar treatment to PRP with somewhat borderline status; almost certainly preferable to corticosteroid but not as good as load management.
So how can we rise above the culture war? Of course the best management of knee OA is exercise therapy or more specifically load management. It is very hard to adequately randomise exercise (over a long time period) in a randomised trial, but observations of populations show that those who exercise in the Goldilocks zone (not too much, not too little) get fewer knee osteoarthritis symptoms14 and also the general health benefits of exercise15.
Exercise therapy is the “solar panels” of musculoskeletal treatment
Adding exercise is the correct treatment for somebody who is not loading enough, but adding exercise is incorrect treatment for somebody who is loading too much (hence load management > exercise therapy). Load management is the electric vehicle or solar panel equivalent in the knee OA treatment armory and is inadequately funded so, sadly, entire populations don’t get great access to this treatment. Knee arthroscopy, NSAIDs, opiates and corticosteroid injections are the fossil fuel equivalents, all (net) harmful and all still funded heavily by the strong arm of vested interests, who promote mainstream medicine “always knows best” as part of a culture war. I see knee replacement as a potentially-valuable but highly-invasive treatment for end stage knee OA that you preferably don’t want to have (i.e. you don’t want your knee OA to get so bad that you need a replacement). I see PRP injections as being like a hybrid fossil fuel/electric vehicle. If you can get pain relief from PRP injections, it has very few of negatives of the nastier treatments and hence is better than them. But it is not as good as load management. Furthermore on the analogy with climate change mitigations, we need to try to reduce the carbon footprint of medical treatments themselves, particularly poor medical treatments.
Mainstream medicine has many, many great treatments, and we’d like the ruling views of mainstream medicine to be always in alignment with the scientific evidence. It has been very frustrating to have lived through a pandemic where a highly beneficial intervention (COVID vaccination) which is promoted appropriately by mainstream medicine is part of a culture war against an anti-vaxxer mob that has decided it doesn’t trust mainstream medicine. But it is equally frustrating to practice in musculoskeletal medicine where mainstream medicine is promoting/funding so many dubious knee OA treatments7 and is frankly refusing to switch to (the very few) better options. Table 1 is a sorry tale of inappropriate treatments getting promoted and funded which is the reason why our outcomes (on knee OA) in the Western World keep getting worse16.
Author and Affiliations:
John Orchard @DrJohnOrchard AM MD PhD FACSEP FFSEM (UK) FACSM
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- Forogh B, Mianehsaz E, Shoaee S, et al. Effect of single injection of platelet-rich plasma in comparison with corticosteroid on knee osteoarthritis: a double-blind randomized clinical trial. J Sports Med Phys Fitness 2016;56(7-8):901-8.
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- Inge P, Perera N, Orchard J, et al. Exercise as Medicine—Evidence for Prescribing Exercise for the National Health Priority Areas: An Umbrella Review. J Postgrad Med Edu Res 2020;54(4):178-205, https://www.jpmer.com/abstractArticleContentBrowse/JPMER/22/54/4/22555/abstractArticle/Article.
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- Pelletier JP, Raynauld JP, Abram F, et al. Intra-articular corticosteroid knee injection induces a reduction in meniscal thickness with no treatment effect on cartilage volume: a case-control study. Sci Rep 2020;10(1):13789.
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- Wijn SRW, Rovers MM, van Tienen TG, et al. Intra-articular corticosteroid injections increase the risk of requiring knee arthroplasty. The bone & joint journal 2020;102-b(5):586-92.
- Perry TA, Wang X, Nevitt M, et al. Association between current medication use and progression of radiographic knee osteoarthritis: data from the osteoarthritis initiative. Rheumatology (Oxford, England) 2021;60(10):4624-32.
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