Abstract
BACKGROUND: Triamcinolone acetonide (TA) injections are widely used for tendinitis but have deleterious effects, including tendon degeneration or tendon rupture. PURPOSE: To investigate whether adding platelet-rich plasma (PRP), a blood fraction that participates in tissue repair processes, to TA can prevent its deleterious effects. STUDY DESIGN: Controlled laboratory study. METHODS: Rat Achilles tendons were injected with TA, TA + PRP, PRP alone, or saline (control). Biomechanical testing and histological analyses were performed on Achilles tendons 1 week after injections. RESULTS: The maximum failure loads in the control, TA, TA + PRP, and PRP groups were 31.7 ± 2.3, 19.0 ± 3.6, 31.0 ± 7.1, and 30.2 ± 6.8 N, respectively. The tendon stiffness in the control, TA, TA + PRP, and PRP groups was 12.1 ± 1.8, 7.5 ± 1.8, 11.0 ± 2.8, and 11.3 ± 2.5 N/mm, respectively. The maximum failure load and stiffness were significantly lower in the TA group compared with the other 3 groups. There was no significant difference between the TA + PRP and control groups. Cell invasions, vacuolation, collagen attenuation, and increased type III collagen expression were histologically observed in the TA group; however, these changes were prevented by the simultaneous administration of PRP. CONCLUSION: Administering PRP may prevent deleterious effects caused by TA; therefore, PRP may be used as a protective agent in clinical situations. CLINICAL RELEVANCE: PRP can be useful as a protective agent for sports injury patients receiving local corticosteroid injections.