Real-time shear wave elastography and high-frequency ultrasound in the assessment of treatment outcomes for triceps surae muscle injury

To evaluate the diagnostic and prognostic value of real-time shear wave elastography (SWE) combined with high-frequency ultrasound (HFUS) and power Doppler imaging (PDI) in assessing triceps surae muscle injury severity and treatment outcomes. Sixty patients with clinically diagnosed unilateral acute triceps surae muscle injury were prospectively enrolled. HFUS assessed muscle structural integrity, PDI evaluated neovascularization using a 4-grade scale, and SWE measured speed of sound values (C) including maximum (Cmax), minimum (Cmin), and mean (Cmean) values. Measurements were performed at three points: 10 mm proximal to the musculotendinous junction of the medial gastrocnemius head (P point), at the musculotendinous junction (MTJ point), and 10 mm distal to the junction (D point). Assessments were conducted at baseline and at 4, 8, and 12 weeks post-treatment. The contralateral healthy limb served as control. All patients received standardized conservative treatment based on the PRICE protocol during the acute phase, followed by a supervised progressive four-phase rehabilitation program over 12 weeks. At baseline, injured sites showed lower speed of sound values compared to healthy controls (P < 0.001). Measurements at different time points (baseline, week 4, week 8, and week 12) showed gradual improvement in speed of sound at the P, MTJ, and D points, nearing control values by week 12. Enhanced PDI signals (Grade 2–3) improved to Grade 0–1 in 85% of patients by week 12. ROC analysis showed high diagnostic accuracy for combined HFUS-SWE assessment (AUC = 0.94, sensitivity 91.7%, specificity 88.3%). Speed of sound at 4 weeks predicted full recovery at 12 weeks (r = 0.78, P < 0.001). Combined HFUS, PDI, and SWE provides comprehensive quantitative assessment of triceps surae muscle injury and healing progression. SWE-derived speed of sound measurements offer objective biomechanical markers for monitoring treatment response and assessing recovery outcomes, which may help inform return-to-activity decisions in similar patient populations. These findings require further validation in diverse cohorts and clinical settings before widespread clinical implementation.