Extracorporeal shock waves promote healing of collagenase‐induced Achilles tendinitis and increase TGF‐β1 and IGF‐I expression

Abstract

Extracorporeal shock waves (ESW) have recently been used in resolving tendinitis. However, mechanisms by which ESW promote tendon repair is not fully understood. In this study, we reported that an optimal ESW treatment promoted healing of Achilles tendintis by inducing TGF-PI and IGF-I. Rats with the collagenease-induced Achilles tendinitis were given a single ESW treatment (0.16 mJ/mm' energy flux density) with 0, 200, 500 and 1000 impulses. Achilles tendons were subjected to biomechanical (load to failure and stiffness), biochemical properties (DNA, glycosaminoglycan and hydroxyproline content) and histological assessment. ESW with 200 impulses restored biomechanical and biochemical characteristics of healing tendons 12 weeks after treatment. However, ESW treatments with 500 and 1000 impulses elicited inhibitory effects on tendinitis repair. Histological observation demonstrated that ESW treatment resolved edema, swelling, and inflammatory cell infiltration in injured tendons. Lesion site underwent intensive tenocyte proliferation, neovascularization and progressive tendon tissue regeneration. Tenocytes at the hypertrophied cellular tissue and newly developed tendon tissue expressed strong proliferating cell nuclear antigen (PCNA) after ESW treatment, suggesting that physical ESW could increase the mitogenic responses of tendons. Moreover, the proliferation of tenocytes adjunct to hypertrophied cell aggregate and newly formed tendon tissue coincided with intensive TGF-PI and IGF-I expression. Increasing TGF-Dl expression was noted in the early stage of tendon repair, and elevated IGF-I expression was persisted throughout the healing period. Together, low-energy shock wave effectively promoted tendon healing. TGF-PI and IGF-I played important roles in mediating ESW-stimulated cell proliferation and tissue regeneration of tendon.

Extracorporeal Shock Wave Treatment Improves Incisional Wound Healing in Diabetic Rats

“…Increasing the endogenous release of growth factors is one potential mechanism by which ESWT facilitates tissue repair. Up-regulation of TGF-β1 expression following ESWT has been observed in various cell types, such as dermal fibroblasts (Berta et al 2009), tenocytes (Chen et al 2004a), mesenchymal stem cells, chondral cells and osteoblastic cells (Chen et al 2004b). In the proliferative phase, TGF-β1 is mainly released from fibroblasts.…”

Microvascular Response to Shock Wave Application in Striated Skin Muscle

“…Enhanced cellular proliferation and regeneration by proliferating cell nuclear antibody (PCNA) and insulin-like growth factor (IGF-I) were demonstrated after ESWA of rat Achilles tendons [8]. Furthermore ESWA has been shown to exert a significant synergistic growth inhibitory effect on tumour cells when applied in combination with chemotherapeutic agents [9,10], which was explained by CP-induced permeabilization of cellular membranes and intercellular connections [11,12].…”

An Evaluation of the Efficacy of ESWT and Placebo-ESWT Treatment for Chronic Plantar Fasciitis

“…Although the mechanism of the effect of ESWT has not been completely determined, the stimulation of the nerve endings in the painful points is thought to cause an inhibition in the pain reflex (hyper stimulation analgesia). In addition, ESWT has been shown to provide neovascularization in tissues [7], to stimulate expression of some mediators such as transforming growth factor beta-1 (TGF-β1), and insulin-like growth factor 1 (IGF-1) and to start the healing process [8].…”