Platelet-rich plasma (better known as PRP) delivers a high concentration of platelets—an important component of blood that plays a role in healing injured tissues—to lesions, increasing the amount of growth factors at the site to, hopefully, help the injury heal. Veterinarians frequently used PRP to heal soft tissue injuries. They use extracorporeal shock wave therapy (ESWT) to simulate healing and trigger cell-specific responses to injury. So would applying shock wave after PRP administration enhance the release of growth factors from PRP and promote better tissue healing?
That’s exactly what a research team led by Kathryn Seabaugh, DVM, MS, Dipl. ACVS, ACVSMR, a sports medicine and rehabilitation specialist at Colorado State University’s (CSU) College of Veterinary and Biomedical Sciences, in Fort Collins, set out to determine.
Seabaugh’s in vitro (in the laboratory) study was the first step in examining ESWT’s effects on PRP. She collected blood and produced PRP from six Quarter Horse mares, then subjected the PRP (contained within a silicone gel pad) to four treatments:
- A positive control (where the PRP was frozen and thawed, a proven method for growth factor release from platelets);
- A negative control (resting, no treatment was administered. This is frequently how PRP is administered in clinical cases);
- A standard shock wave probe; and
- A high-power shock wave probe.
Then, the researchers quantified the growth factors present in each sample following treatment.
Selberg said the team found that the concentrations of two growth factors released from the PRP—platelet-derived growth factor-ββ and transforming growth factor β1—were significantly higher in both shock wave-treated groups than in the negative control group. There was no significant difference between the two shock wave groups, he said.
“The combination of PRP and ESWT might result in a synergy between the two modalities,” Selberg said.
While similar studies have not yet been conducted in vivo (in the live horse), “the data supports the use of ESWT immediately following therapeutic injection of PRP into injured soft-tissue structures in the horse to attempt to increase the concentrations of growth factors released from the platelets,” the research team concluded.