This laboratory study compared three PRP preparation systems — two single-spin (Arthrex ACP and Biomet GPS III) and one double-spin — in eight healthy subjects. It measured platelet count, red and white blood cell concentrations, and seven growth factors. It also tested whether repeated blood draws from the same individual produce consistent PRP over time.
The PRP literature is plagued by contradictory results, and this paper explains a major reason why: two studies using 'PRP' may be comparing completely different biological products depending on which device was used.
When choosing a PRP system, recognize that device selection determines leukocyte content as much as platelet count. If leukocyte-poor PRP is your goal (e.g., for intra-articular injection where inflammation is a concern), the Arthrex ACP-type system is the appropriate choice. If leukocyte-rich PRP is intended (e.g., for tendon or muscle applications where antimicrobial and growth factor effects may be desired), a GPS III-type system achieves that — but delivers 34× more WBCs alongside the platelets.
For serial PRP injections, do not assume the patient receives an equivalent dose each time. Cronbach's α below 0.7 for every PRP method tested means repeated draws produce unpredictably different preparations. Treat PRP 'dose' as an approximation, not a fixed quantity.
One practical anchor: double-spin processing is not worth the added complexity. Single-spin methods clear the >200 × 10³/mL therapeutic threshold and are adequate for clinical use.
This laboratory study compared three PRP preparation systems — two single-spin (Arthrex ACP and Biomet GPS III) and one double-spin — in eight healthy subjects. It measured platelet count, red and white blood cell concentrations, and seven growth factors. It also tested whether repeated blood draws from the same individual produce consistent PRP over time.
The PRP literature is plagued by contradictory results, and this paper explains a major reason why: two studies using 'PRP' may be comparing completely different biological products depending on which device was used.
When choosing a PRP system, recognize that device selection determines leukocyte content as much as platelet count. If leukocyte-poor PRP is your goal (e.g., for intra-articular injection where inflammation is a concern), the Arthrex ACP-type system is the appropriate choice. If leukocyte-rich PRP is intended (e.g., for tendon or muscle applications where antimicrobial and growth factor effects may be desired), a GPS III-type system achieves that — but delivers 34× more WBCs alongside the platelets.
For serial PRP injections, do not assume the patient receives an equivalent dose each time. Cronbach's α below 0.7 for every PRP method tested means repeated draws produce unpredictably different preparations. Treat PRP 'dose' as an approximation, not a fixed quantity.
One practical anchor: double-spin processing is not worth the added complexity. Single-spin methods clear the >200 × 10³/mL therapeutic threshold and are adequate for clinical use.