Relationship Between the Amount of Change in Echo Intensity and Young's Modulus of the Soleus Muscle After Ankle Fracture Surgery.

Objective: We aimed to clarify the relationship between the changes in echo intensity (EI) and Young's modulus of the soleus (SOL) muscle after ankle fracture surgery.
Methods: Sixteen participants after ankle fracture surgery participated in this study (mean age: 46.8 ± 21.4 years). At three and five months after surgery, ankle range of motion (ROM), ankle strength, SOL muscle EI, and Young's modulus were measured, and changes in values were calculated. The EI was measured using the B-mode and ImageJ software (National Institutes of Health, Bethesda, MD), and Young's modulus was measured using shear wave elastography (SWE). The EI values corrected for subcutaneous fat thickness were calculated. Correlation and simple regression analysis were used to clarify the relationship between the amount of change in EI, the amount of change in Young's modulus, and the amount of change in ankle ROM.
Results: Simple regression analysis showed that the amount of change in EI influenced the amount of change in Young's modulus of the SOL muscle (r = 0.623; p = 0.010) and the amount of change in ankle dorsiflexion ROM with the knee flexed (r = -0.702; p = 0.002).
Conclusion: The change in EI of the SOL muscle affected the change in Young's modulus after ankle fracture surgery. Clinically, changes in the EI may reflect changes in muscle stiffness.
Competing Interests: Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. The Ethics Committee of Tsuchiura Kyodo General Hospital issued approval (2024FY32). The study was conducted in accordance with the Declaration of Helsinki. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.
(Copyright © 2024, Miyasaka et al.)