Injuries are by no means enjoyable, and desperate times can cause patients to go to desperate measures. When consulting with patients who fit this description it isn’t uncommon to be be asked, “You know those blood injections, person x said it would work, would one help me?”
Having stumbled across people suggesting “PRP” on all kinds of platforms, we thought we would take the time to explain PRP, what it is supposed to do and whether or not it works.
PRP stands for Platelet Rich Plasma. PRP is made by extracting blood from a person, spinning it to separate plasma from red blood cells, then using or administered by injection back into the affected area.
The theory behind the PRP injection was that it could assist with or accelerate tissue repair, as it contains multiple “growth factors”. Because of the associated healing properties the PRP injections were considered and used for acute muscle or tendon injuries. However, when looking at this protocol under the microscope, level 1 medical evidence suggests otherwise.
A Cochrane review 2014 looked at a review of 19 trials of PRP (with a control group of placebo injection, blood injection (non PRP), dry needling or no injection). Most injuries treated were tendon related: elbow, patella, and achilles.
In summary there was no differences between groups in the short, medium and long term follow up. There was a slight difference in pain in the short term only, but when examined in the medium or long term follow up there was no difference.
Acute muscle strain
Again there is no evidence what-so-ever that PRP works. A meta-analysis for acute hamstring strains showed superior efficacy for physiotherapy and rehabilitation exercises. PRP injection had no effect on acute hamstring injury, return to play or re-injury rates (Pas, 2015).
This result is now widely supported. Another research example is a randomised, three-arm (double-blind for the injection arms), parallel-group trial, in which 90 professional athletes with MRI positive hamstring injuries were randomised to injection with PRP-intervention, platelet-poor plasma (PPP-control) or no injection. All received an intensive standardised rehabilitation programme. The primary outcome measure was time to return to play, with secondary measures including reinjury rate after 2 and 6 months.
Again the findings/evidence (Hamilton, 2015) indicate that there is no benefit of PRP, that an injection program or treatment offers no benefit compared to intensive rehabilitation in athletes who have sustained acute, MRI positive hamstring injuries.
Yes I have seen several patients who have reported ‘great results’ using this intervention, and sometimes they argue against the best conducted medical trials. In consideration of this;
- PRP may work for a specific subgroup, or type of tendon injury or joint injury. However, to date there is no published study discussing exactly what type of specific problem it may benefit.
- If used on tendon or muscle they may have just naturally progressed back to the “norm”. If symptoms were present for a short period of time, they may have got better anyway! Particularly with a couple of weeks of enforced rest (“unload/modify load”, and “optimised” / gradual reloading (which is often encouraged after PRP injections)
- Placebo/the associated belief behind the treatment intervention is powerful! (Especially with expensive placebo treatments)
- PRP injections are often used in conjunction with proven physiotherapy strengthening interventions addressing the underlying deficiencies.
In conclusion we feel that patients need to remember that there are proven treatments for musculoskeletal conditions. If reading the proposed benefits whilst googling, reading blog articles or testimonials surrounding PRP, we encourage you always look at the quality of the evidence supporting certain claims.
Now with an abundance of high quality medical trials and research showing the PRP is sketchy at best, does it really like up to the hype?