The Biological Effect of Platelet-Rich Plasma on Rotator Cuff Tears: A Prospective Randomized In Vivo Study

Area of Science:

• Orthopedics
• Regenerative Medicine
• Biomaterials Science

Background:

• Platelet-rich plasma (PRP) demonstrates positive effects on tendon metabolism in vitro and enhances tenocyte activity in animal models of tendon degeneration.
• The in vivo effects of PRP on human tendon biology, particularly in degenerative tears, remain less understood.

Purpose of the Study:

• To prospectively evaluate the in vivo effect of autologous platelet-rich plasma (PRP) on the microscopic biology of torn human supraspinatus tendons.

Main Methods:

• A prospective randomized comparative study involving 20 patients with degenerative supraspinatus tears.
• Patients received either an ultrasound-guided autologous PRP injection or no injection prior to arthroscopic surgery.
• Tendon specimens were analyzed using optical and electron microscopy to assess cellular and collagen structure.

Main Results:

• Control group tendons showed disorganized collagen, mixed tenocyte morphology, and significant inflammation.
• PRP-treated tendons exhibited abundant oval tenocytes with cytoplasmic processes and predominantly parallel collagen fibers.
• Reduced inflammation was noted in the PRP group, with microscopic features resembling intact tendon structure.

Conclusions:

• Autologous PRP injection induces favorable microscopic changes in torn human supraspinatus tendons in vivo.
• PRP appears to stimulate the tendon healing process, promoting a more organized and less inflamed cellular environment.
• These findings suggest PRP can facilitate more effective recovery from degenerative supraspinatus tendon tears.