BackgroundThis study aimed to evaluate the predictive value of anthropometric measurements for two-stranded peroneus longus tendon (PLT) graft thickness using ultrasonographyMaterials and methodsA prospective study was conducted on 204 healthy volunteers (102 males and 102 females) aged 18–40 years. Anthropometric measurements were recorded, including height, weight, body mass index (BMI), fibular length, calf circumference, and ankle circumference. The Tegner Activity Scale (TAS) was used to assess activity levels. PLT cross-sectional area (CSA) was measured using ultrasonography. Two-stranded PLT graft thickness was calculated using the previously reported formula by Luo et al. A thickness of less than 8 mm of PLT graft was accepted as an insufficient autograft for anterior cruciate ligament reconstruction (ACLR). Correlation and regression analyses were performed to identify predictors of two-stranded PLT graft thickness. Receiver operating characteristic (ROC) analysis was performed to establish the best threshold values.ResultsMales had a significantly greater PLT CSA (0.17 ± 0.03 cm2) and predicted two-stranded PLT graft thickness (8.1 ± 0.6 mm) compared with females (0.15 ± 0.03 cm2 and 7.5 ± 0.6 mm, respectively; p < 0.001 for both). Correlation analysis revealed that two-stranded PLT graft thickness positively correlated with height, weight, BMI, fibular length, calf circumference, ankle circumference, and Tegner Activity Scale in both genders, with stronger correlations observed in females. The logistic regression model identified height and calf circumference as significant predictors of sufficient two-stranded PLT graft thickness (≥ 8 mm) in males, while calf circumference and the TAS were significant predictors in females. ROC analysis demonstrated that calf circumference and the TAS had acceptable discriminatory abilities in females, with 36.25 cm and ≥ 4 cutoff points, respectively. However, no anthropometric variables in males exhibited strong discriminatory abilities for predicting two-stranded PLT graft thicknessConclusionsCalf circumference and the TAS are significant predictors for two-stranded PLT autograft thickness in females. However, no anthropometric variables in males could be used strongly for prediction. These anthropometric measurements can assist in preoperative planning and decision-making, potentially improving ACLR outcomes by ensuring adequate graft thickness in females.Level of evidence: Level II prospective study