Novel Modalities & Normative Ultrasound Measures to Inform Clinical Care of Posterior Lower Extremity Injuries in a Military Treatment Facility- MHSRS 2025
rossi r, cin l, grogan s, persinger j, schroeder j, hager n, mincey c, metzger e, gabler g, wagner l, yuan x, isaacson b, pasquina p
Abstracted accepted for a poster session at the 2025 Military Health System Research Symposium
Introduction: Lower extremity injuries are common sources of limited duty days for military Service Members. Microvascular flow (MVF) & shear wave elastography (SWE) are postulated to be non-invasive, efficient, & cost effective in early diagnosis/treatment of musculoskeletal injuries (MSKIs). Normative values for MVF, SWE, & related tendon echo-characteristics in the lower leg & Achilles tendon do not exist to our knowledge. Studies reported gender variability of the patellar tendon on ultrasound. Further investigation is needed to determine if there are similar variations in the Achilles tendon. This study aimed to establish normative values for routine tendon echo-characteristics, presence of plantaris tendon, MVF vs P ower Doppler (PD), & SWE measurements in the posterior lower leg & Achilles tendon.
Methods: Ultrasound was performed on asymptomatic participants on a Samsung RS-85 Prestige. Measurements: Achilles calcaneal insertion (CI), avascular zone (AVZ), gastro-soleus junction (GSJ), medial gastrocnemius, & soleus. Outcomes: thickness/width 2D measurements, vessel quantification (PD vs MVF), SWE, plantaris tendon presence, Body Mass Index (BMI), ankle Range of Motion (ROM), & surveys.
Results: 106 limbs scanned (n=55). MVF detected flow in 9 limbs vs 1 limb by PD. Increased BMI increased tendon/gastroc measurements: (p < .01); SWE [r(63) = 0.41] & AVZ SWE [r(63) = .33]. No correlations found between activity levels & ultrasound or ROM measures (p>0.1). Mean SWE of AVZ Short-Axis (SAX) significantly different in males vs females [79.3 kPa (SD: 25.5) vs 64.0 kPa (SD: 10.3), respectively], p=.01). Mean SWE CI: Males: 133.1 kPa (SD: 25.0), females: 124.2 (SD: 31.7); no significant gender differences (p>.01). Median GSJ height Long-Axis (LAX): 0.2 cm. Median CI LAX: 0.4 cm. AVZ height LAX: 0.5 cm. SAX, mean AVZ width: 1.5 cm (SD: 0.2) males & 1.4 cm (SD: 0.2) females; no significant gender differences (p>.01). Plantaris tendons found in 56% of participants. Mean ankle dorsiflexion: males = 13.1° (SD: 10.1), females = 7.2° (SD: 9.9), p=.01.ion.
Conclusion: SWE varied between genders & ultrasound sites. Increased BMI increased tendon/gastroc measurements; higher activity levels did not. Tendon architecture greater in males than females & MVF more sensitive than PD. These findings will inform normal, routine, & novel ultrasound values for the Achilles tendon complex to improve diagnosis & treatment of MSKIs in Military Treatment Facilities