SkinFibroMeter in lower extremity lymphedema assessment: Reliability, correlation with ultrasound, and the determination of minimal detectable change

Objectives This study aimed to determine the inter- and intra-rater reliabilities of the SkinFibroMeter in individuals with lower extremity lymphedema. The secondary aim was to examine its correlation with skin/subcutaneous tissue thickness and establish minimal detectable change (MDC 95 ) values. Methods Thirty lower extremities with physician-diagnosed lymphedema were included in this cross-sectional study. Tissue stiffness was assessed at standardized anatomical sites using the SkinFibroMeter® by four raters with varying clinical experience. Skin and subcutaneous tissue thickness were measured at the same points via ultrasound (US). Inter- and intra-rater reliabilities were evaluated using intraclass correlation coefficients (ICC), and the standard error of measurement and MDC 95 were calculated. Results Participants had a mean age of 68 ± 11.9 years, a mean BMI of 34.0 ± 6.0 kg/m 2 , and a mean limb volume of 10,020 ± 3,148 mL. Intra-rater reliability ranged from moderate to excellent (ICC = 0.600–0.976), while inter-rater reliability varied by site (ICC = 0.647–0.941), with the highest agreement at 20 cm above the patella and the lowest at the foot dorsum. Bland–Altman analysis confirmed acceptable absolute agreement across rater pairs with negligible systematic bias. Low-to-moderate positive correlations were observed between the indentation values of the SkinFibroMeter and skin thickness (r = 0.377–0.556, p < .05), whereas negative correlations were found with subcutaneous thickness at several points (r = −0.508 to −0.421, p < .05). No statistically significant correlation was found between localized stiffness and total limb volume (r = −0.023, p = .907). MDC 95 values ranged from 0.013 to 0.158. Conclusion The SkinFibroMeter demonstrates acceptable clinical reliability, with values representing a complex interplay of dermal thickness, interstitial hydration, and tissue compliance rather than global limb size or pure fibrosis. This is the first study to establish MDC 95 thresholds, providing clinicians with reference baselines for treatment-related changes. Future studies should incorporate larger, stage-homogeneous cohorts using 3D scanning and shear-wave elastography for comprehensive tissue characterization.