Comparison of Conventional Dose Versus Superdose Platelet-Rich Plasma for Knee Osteoarthritis: Letter to the Editor

Dear Editor:

I read the study entitled “Comparison of Conventional Dose Versus Superdose Platelet-Rich Plasma for Knee Osteoarthritis” by Patel et al ² with great excitement. I would like to add a few perspectives to this valuable work, as future studies will advance our knowledge about platelet-rich plasma (PRP), which is today's popular topic.

The purpose of this study was to compare the outcomes for conventional and superdose PRP for knee osteoarthritis. The authors included patients with early knee osteoarthritis. Group A (n = 50 knees) received a 4-mL PRP injection, and group B (n = 49 knees) received an 8-mL PRP injection. Before receiving the injections, the patients were given a trial of nonsteroidal anti-inflammatory drugs and were started on a physical therapy protocol. Outcomes were measured with pain scoring systems and osteoarthritis indexes at baseline, 6 weeks, 3 months, and 6 months.

There was no placebo-controlled group in the study, and the participation of this group is important in determining the success of new treatments. Last year, Chan et al ¹ published a review entitled “Statistical Fragility of Randomized Controlled Trials Evaluating Platelet-Rich Plasma Use for Knee Osteoarthritis.” In their study, 8 randomized clinical trials and 678 patients were included. Their conclusion was there is a lack of statistical stability in the literature evaluating the efficacy of PRP. Another part I would like to point out is that the duration and frequency of the physical therapy program were not specified in the article. Medical treatments, injections, physical therapy protocols, and life modifications for nonsurgical treatment of knee osteoarthritis have been examined frequently in the literature. We as readers have no information regarding whether the physical therapy program applied before the PRP injection continued or not, and we doubt that short-term programs performed only before the injection will have this effect. ² In a study using a combined treatment protocol, researchers will examine the effectiveness and safety of exercise applications combined with PRP injections. ³

In conclusion, the study conducted by Patel et al ² made valuable contributions to the literature in terms of comparing superdose PRP and conventional-dose PRP. It helps us better understand PRP treatment and its types, which is an increasingly popular treatment method today. There are some limitations to this study that should be considered when interpreting the data. When the literature is evaluated, it is understood that there is no definitive evidence regarding the effectiveness of PRP treatment. Including a placebo-controlled group in the study design could have provided information missing in the literature.

Another drawback is that limiting the physical therapy plan to the preinjection period may negatively affect the long-term effectiveness of the treatment. It would be useful to point out whether combined physical therapy application had been continued. After considering these issues, we can better evaluate the effectiveness of PRP injections in future studies. I am eagerly awaiting studies that will demonstrate the effect of the intensity of its content and its use in isolated and combined treatments on success.

Caner Poyraz, MD Izmir, Turkey