Intra-articular use of a platelet-rich product in normal horses: clinical signs and cytologic responses.

This research study explores the effects of injecting a platelet-rich product (PRPr) into the joints of healthy horses, the endurance of platelets within joint fluid post-injection, the reactions to varying treatments using this product, and the efficacy of a gravity filtration system in creating PRPr in horses. Results indicate that specific PRPr treatments increase white blood cell concentration in joint fluid and that platelets can be seen in joint fluid up to five days after injection. Furthermore, the study suggests that a gravity filtration system can effectively prepare PRPr, thereby eliminating the need for centrifugation.

Objective and Methodology of the Study

• The research had four primary objectives: to examine the clinical and synovial effects of a PRPr on normal horse joints, assess the longevity of platelets in synovial fluid post PRPr injection, compare responses to different treatments using the product, and test the effectiveness of a gravity filtration system for PRPr creation in horses.
• The experimental method involved preparing a platelet-rich saline product (PRPr) from seven healthy horses with the help of a distinctive preparation device. The resultant product was split into three treatment types: resting, activated with calcium chloride (CaCl2 -activated), and activated with bovine thrombin.
• Each horse was given three concurrent intra-articular PRPr treatments in their metacarpophalangeal/metatarsophalangeal joints, with the fourth limb receiving saline solution as a control. Observations, including clinical assessments and cytologic analysis of synovial fluid and hemograms, were taken at four different time points – 6, 24, 48, and 96 hours post-injection.
• The PRPr composition and growth factor content were also analyzed during the process.

Findings of the Experiment

• The gravity filtration system succeeded in producing a moderately concentrated PRPr.
• PRPr treatments caused a significant rise in synovial white blood cell (WBC) concentration and neutrophil percentage at 6 and 24 hours as compared to control values.
• The bovine thrombin-activated PRPr injection resulted in increased effusion scores and periarticular signs.
• Throughout the experiment, the synovial WBC concentration was significantly higher post thrombin-activated PRPr injection, in comparison to the control, CaCl2 -activated, or resting PRPr.
• Intact platelets were visible in the synovial fluid for up to 5 days following intra-articular PRPr injection.

Conclusions from the Study

• The Researchers concluded that resting and CaCl2 -activated PRPr could be safely used to treat equine joints. In contrast, the bovine thrombin activation, particularly at 10 U/mL, is not recommended.
• It was also found that a gravity filtration system could effectively prepare PRPr, which eliminates the need for using the centrifugation method.