During this morning live broadcast on Facebook of PodChatLive (and its on YouTube) we were discussing paediatric flatfoot and paediatric foot orthoses with Helen Banwell, a question from came in from Marc Barton that got me thinking.
I have to be honest and admit that the use of platelet rich plasma (PRP) for plantar fasciitis is something that I have had no more than a superficial interest in. I pretty much scanned the abstracts of the studies and systematic reviews as they are published of it in this thread and the one comparing it to other interventions on Podiatry Arena. I also note comments in social media on it from those whose views I respect. From my superficial understanding, it works, it does not work, it works, it does not work … a lot of the studies that compare it to other treatments do not do the “other” treatment very well (ie wrong dosing), which can easily bias the study to PRP being better. Some of the comments in social media from people who I consider real experts, especially in the context of tendinopathy are that it does not work, yet a lot of people claim it does. Yes, I know that the “plantar fasica” is not a “tendon” and it may or may not be appropriate to translate “tendinopathy” research to “plantar fasciitis” (not that this stops people doing so or not doing so if the research on it matches their pre-conceived biases!).
The concept of foot orthotic dosing is something that has been bubbling away under the surface for a long time now, but for some reason, not a lot of noise gets made about it, or when noise is made about it, tends to get dismissed by those who want to protect the way they did things.
To introduce the concept, consider this hypothetical analogy: what if a really well conducted clinical trial was done on a very low dose of an anti-hypertensive drug and it shows that the drug does not work at that dose. Should that be used as evidence that the drug is not effective? Of course it shouldn’t, but that is exactly what is done with clinical trials of foot orthoses at low doses. As the methodology and analysis of that hypothetical drug trial was sound, should it be included in the systematic reviews and meta-analyses? It will meet all the textbook criteria to be included in a systematic review and meta-analysis, but, of course, it should not be included as the dose was low. To include it would probably be unethical as it would unreasonably bias the systematic review and meta-analysis in the direction of the drug not working (unless the review stratified the study results into different doses). It makes sense to exclude that study because of the low dose. So, why then is it acceptable to do exactly that in systematic reviews and meta-analyses of foot orthoses?
I am having a bad weekend commenting on bad research. There were these two dumb studies on Homeopathy for Heel Spurs and this one on the non-existent anterior metatarsal arch. In the Clinical Biomechanics Boot Camp I really try to focus on the practical application of research, so really look for research that is translatable to clinical practice. If it’s not translatable, then what was the point of doing it? There is way too much foot orthotic research being done lately that is not translatable, wasting resources and not providing clinicians the sort of information that they need to do it better.
What brought this up for me today was this study in quite a prestigious online journal (PLoS ONE) that really tells us nothing. The only thing I get from this study is I can add it to the list of studies I use when trying to illustrate how not to do foot orthotic research.
Just put together a video for the Clinical Biomechanics Boot Camp on ‘Clinical Practice Can be Deceptive’ wrestling with an issue I can’t quite get my head around. Sometimes writing about it helps me think clearer, so here goes: