Ultrasound biomicroscopy and claudication test for in vivo follow-up of muscle repair enhancement based on platelet-rich plasma therapy in a rat model of gastrocnemius laceration.

Cristiane Lima Pinheiro,Cristiano Costa Esposito,João Carlos Machado,Carolina Carneiro Peixinho,José Eduardo Ferreira Manso

doi:10.1590/s0102-865020160020000004

Cristiane Lima Pinheiro, Cristiano Costa Esposito + Show 3 more

Open Access

https://doi.org/10.1590/s0102-865020160020000004

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Abstract

To track the regeneration process of lateral gastrocnemius due to a muscle laceration in rats, and to treatment with plateletrich plasma (PRP). Ultrasound (40 MHz) images were used for measuring pennation angle (PA), muscle thickness (MT) and mean pixel intensity, along with claudication scores, of treated (PRPG) and non-treated (NTG) groups of rats. NTG showed a PA increase for the non-injured leg (p<0.05) and a tendency of MT to increase, whereas for PRPG there were no differences. There was a progressive reduction of the claudication score for the PRPG group throughout the entire period, with an immediate difference after seven days (p<0.05), whereas the NTG had a significant reduction only at day 28 (p<0.05). It was observed a compensatory hypertrophic response due to the overload condition imposed to healthy leg for NTG that did not occur in PRPG, suggesting an accelerated repair process of the injured leg due to treatment, anticipating its use.

Highlights

Musculoskeletal injuries represent a worldwide concern for health care, affecting millions of people around the world[1], restricting daily living activities, imposing lost working days, and causing lifelong pain.Traditional management of muscle injuries includes RICE (Rest, Ice, Compression and Elevation) treatment, physical therapy, corticosteroid injections and surgical intervention
Typical ultrasound biomicroscopy (UBM) images from right hindlimb of NTG and PRPG groups are presented in Figures 1 and 2, respectively
The similarity of results in both animal studies concern, in a first instance, the qualitative changes on the injured muscle tissue images acquired 7 and 14 days after the injury (Figures 1 and 2) compared to those obtained for the healthy muscle. Such similarities include: the onset of hypoechoic areas without distinguishable fiber structures in the sites previously formed of muscular tissue, which was corroborated by a lower mean of the image pixel intensity (MPI), and the significant increase in MT immediately after the injury

Summary

Introduction

Musculoskeletal injuries represent a worldwide concern for health care, affecting millions of people around the world[1], restricting daily living activities, imposing lost working days, and causing lifelong pain.Traditional management of muscle injuries includes RICE (Rest, Ice, Compression and Elevation) treatment, physical therapy, corticosteroid injections and surgical intervention. Platelet-rich plasma (PRP) gained popularity in the clinical treatment of injured musculoskeletal tissues[6] in order to reduce inflammation and fibrosis, while accelerating muscle fiber regeneration[7]. PRP contains growth factors and three proteins in blood known to act as a matrix for bone, connective tissue, and epithelial migration[8]. Despite the contributions of basic research supporting the use of PRP to improve the healing of injured muscles, clinical evidence for PRP therapy is not yet established. The reasons are due to unanswered questions concerning the dosing, timing, and frequency of PRP injections; distinct techniques for delivery and delivery location (over or within the injured tissue site, or intraarticularly); optimal physiologic conditions for injections; and the combined use of recombinant proteins, cytokines, additional growth factors, biological scaffolds, and stems cells[9,10]

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