Pulsed ultrasound treatment accelerates the repair of Achilles tendon rupture in rats

Abstract

A rat tenotomy model was used to investigate the effect of combined conservative management and pulsed ultrasound (PUS) on the repair of tenotomized Achilles tendon. Hemitenotomy of right medial Achilles tendon was performed in 48 rats without suture, and patella tenotomy was performed to mimic immobilization and limb disuse of an injured limb. PUS and sham PUS were applied to the healing wound for the treatment group and control group for 5 min, 3 times per week for 2 or 4 weeks, respectively. Tensile tests showed that the ultimate tensile strength (UTS) and stiffness of the repaired tendon in the treatment group at 2 weeks reached 48.92 AE 18.39% and 62.48 AE 32.46% of the contralateral normal tendon strength, which were significantly higher than those of the control group (UTS, 30.36 AE 15.46%; stiffness, 33.90 AE 17.59; p < 0.05). At 4 weeks, UTS increased to 77.09 AE 15.31% and stiffness to 92.48 AE 31.12% in the treatment group, significantly higher than those in the control group (UTS, 54.33 AE 18.40%, p < 0.01; stiffness, 65.02 AE 25.48%, p < 0.05). Light microscopy revealed more regular, denser, and better aligned collagen fibers in the healing scar of the PUS-treated healing tendons. The findings suggested that PUS were able to accelerate the healing of the ruptured tendons. ß

Low-Intensity Pulsed Ultrasound Accelerates Healing in Rat Calcaneus Tendon Injuries

“…The ability of the tissue to withstand high stress levels is related to the percentage of collagen matrix in the tissue and collagen matrix maturity. 20 Our results are in agreement with those of Yeung and colleagues, 35 who found a more mature scar tissue with a more parallel arrangement of collagen fiber bundles in the tendon that had undergone ultrasound treatment, especially after 4 weeks. These authors 35 also reported improved biomechanical properties, with significantly higher ultimate tensile strength and stiffness in the ultrasound treatment group after 2 and 4 weeks of LIPUS.…”

“…20 Our results are in agreement with those of Yeung and colleagues, 35 who found a more mature scar tissue with a more parallel arrangement of collagen fiber bundles in the tendon that had undergone ultrasound treatment, especially after 4 weeks. These authors 35 also reported improved biomechanical properties, with significantly higher ultimate tensile strength and stiffness in the ultrasound treatment group after 2 and 4 weeks of LIPUS. Cunha et al 3 reported similar results and showed that pulsed ultrasound had a stimulatory effect on the rate of tissue regeneration in a ruptured calcaneus tendon, with improved collagen synthesis and better alignment and aggregation of the collagen fibers.…”

“…7,14,15 In addition, it has been shown that low-intensity pulsed ultrasound has a positive effect on tendon healing. 14,15,35 Although many results are encouraging, the influence of ultrasound on the structural properties of healing tendons is far from being universally agreed upon. 22 Among parameters that influence treatment effectiveness, particular attention must be given to current intensity.…”

Controlled Re-Injury of a Thigh Muscle Tear in a Soccer Player: a Case Study

“…Although there is no promising animal or clinical evidence that US can help repair muscle injuries [20][21][22][23] , there is plenty of evidence showing the effects of US in collagen repair and re-synthesis 25,[33][34][35][36][37][38][39][40][41] . The use of US in the present clinical case was oriented at improving muscle collagen extracellular matrix (CEM) repair, based upon US effects on fibroblast proliferation and collagen synthesis 25,39) .…”

Cambios Morfológicos en la Regeneración del Tendón Calcáneo de Rata (Sprague Dawley) por la Aplicación de Ultrasonido Continuo

“…Este estudio confirma trabajos previos que describen una aceleración de la regeneración tendinosa gracias al uso de ultrasonido (Grass et al;Bassoli;da Cunha et al, 2001;Berná-Serna et al, 2005;Yeung et al, 2006). Por otro lado, se demuestra la presencia de fibroblastos activos en la secreción de matriz extracelular con una rá-pida proliferación celular, lo que lleva, finalmente, a una aceleración de la regeneración tendinosa, posterior a una lesión.…”