The Positive Effects of Different Platelet-Rich Plasma Methods on Human Muscle, Bone, and Tendon Cells
Mazzocca AD, McCarthy MB, Chowaniec DM, Dugdale EM, Hansen D, Cote MP, Bradley JP, Romeo AA, Arciero RA, Beitzel K. Am J Sports Med. 2012 Aug;40(8):1742-9. Epub 2012 Jul 16.
One of the most widely disputed hot topics in sports medicine today is the utilization of PRP. While the theory of how PRP works is solid, there has been a lag in the literature to back it up. At SMR we have covered recent research showing that PRP does and doesn't work. However, one item that hasn't been covered in general is the PRP preparation. While multiple preparation techniques are available commercially, there has not been any independent analysis to delineate which preparation might be better suited in different situations. Therefore, the investigators compared 3 different PRP preparation techniques and the effect on cell proliferation in bone, muscle and tendon tissue harvested post shoulder arthroplasty, latissimus dorsi transfer and biceps tenodesis, respectively. Blood samples were collected from 8 patients, prepared and administered to the tissue types. The 3 preparation techniques were 1) a low platelet concentration technique (PRPLP) achieved through a 5-minute, single-spin at 1500 RPM utilizing the Arthrex double-syringe format. This technique elicited 3mL of PRPLP containing the lowest concentration of platelets (LP). 2) A double spun (PRPDS) preparation was obtained using a previous method as described by de Mos et al. The blood sample was spun for 5 minutes at 1500 RPM then the plasma was drawn up and centrifuged for 20 minutes at 6300 RPM, which separated the plasma/platelets further. 3) A high platelet concentration sample (PRPHP) was obtained through spinning a 27mL blood sample for 15 minutes at 3200 RPM. This separated the sample into 3 distinct layers. The middle layer containing platelets and WBC's was drawn up and utilized for this study. The tissue samples were prepped and isolated through various techniques dependent on the tissue type. Once isolated, 2500cm2 of the tissue samples were placed in petri dishes and exposed to the 3 different PRP samples and monitored microscopically for 96 hours and compared to multiple control samples. After 96 hours, radioactive thymidine was utilized to measure cell proliferation in each sample. Multiple growth factors were also measured for all control and experimental conditions at this time frame. Of the 3 PRP preparation techniques, results indicate that the PRPHP technique elicited the highest concentration of platelets, WBC and growth factors. However, higher concentrations did not necessarily equate to increased cell proliferation in all tissue types. PRPLP and PRPDS both showed significant increase in osteoblast proliferation when compared to controls. PRPLP and PRPDS also showed significantly higher levels of myocyte proliferation when compared to control and PRPHP preparations. Tenocytes exhibited significant proliferation for all PRP conditions when compared to controls, but no significant difference existed when compared to the other preparations.
This study is interesting for a few reasons, due to the fact that we still do not truly understand how PRP works or where its sports medicine utility lies. The results from this study state the case that preparation might be an integral component to the success/failure of the intervention. One item that must be examined is the concentration of growth factors in all preparations. The PRPHP technique elicited the greatest quantity of each growth factor examined across all tissue types, but not the highest levels of cell proliferation. That begs the questions: 1) Are the growth factors as integral to PRP's success as we previously believed, or is there an optimal range? 2) Does PRP have different effects predicated for different tissue types? The authors do state that this study isn't without limitations, most notably that an in-vitro setting might not accurately reflect PRP's in-vivo properties. What are your thoughts on this study? What PRP techniques do you and your physicians utilize? Would you consider different preparations based upon what type of tissue is injured?
Written by: Mark Rice
Reviewed by: Stephen Thomas