Preoperative Platelet-Rich Plasma Injections Decrease Inflammatory and Chondrodegenerative Biomarkers in Patients With Acute Anterior Cruciate Ligament Tears: A Pilot Randomized Controlled Trial.

Background: Posttraumatic osteoarthritis occurs at an alarming rate after anterior cruciate ligament (ACL) injury and reconstruction (ACLR).

Purpose/hypothesis: The purpose of this pilot randomized controlled trial was to evaluate the preoperative effect of a 2-injection series of platelet-rich plasma (PRP) on the progression of inflammatory and chondrodegenerative biomarkers before ACLR. It was hypothesized that preoperative PRP injections would decrease the chondrotoxicity of the presurgical knee fluid.

Study Design: Randomized controlled trial; Level of evidence, 1.

Methods: A total of 24 participants were randomized to either a control or an intervention group. Both groups received joint aspirations within the first 10 days after ACL injury (visit 1). In addition to joint aspiration at visit 1, the PRP group received a leukocyte-poor, nonactivated PRP injection at visit 1 and an additional PRP injection 5 to 12 days after the initial visit (visit 2). Joint fluid samples were harvested in both groups at the time of ACLR (visit 3). The joint fluid and PRP samples were subject to inflammatory and chondrodegenerative biomarker analysis for the following: interleukin (IL)-1ß, IL-10, IL-6, granulocyte-macrophage colony-stimulating factor, IL-5, interferon (IFN)-γ, tumor necrosis factor-α, IL-2, IL-4, and IL-8.

Results: The final analysis was completed on 8 participants in the control group and 8 in the intervention group. At visit 1, no significant differences were observed in cytokine concentrations between the control and intervention groups. Between visits 1 and 3, the control group demonstrated significant decreases in IL-8 ( = .007) and IFN-γ ( = .007), whereas the intervention group demonstrated significant decreases in all cytokine concentrations ( < .05) except for IL-8 ( = .08). At visit 3, similar to visit 1, no significant group differences were observed in cytokine concentrations. The PRP products in the intervention group were analyzed using complete blood counts and were consistent with defined concentrations found in leukocyte-poor PRP product.

Conclusion: Intervention with aspiration combined with a 2-injection series of leukocyte-poor PRP in the acute ACL-injured knee resulted in a significant reduction in effusion inflammatory markers, whereas the control aspiration (without PRP injections) did not show such marker reduction.

Registration: NCT04088227 (ClinicalTrials.gov identifier).