Ultrasound shear wave elastography-derived tissue stiffness predicts intra-articular lesions of the long head of the biceps tendon.

BACKGROUND

Rotator cuff tears often coexist with intra-articular lesions in the long head of the biceps tendon (LHBT). Currently, biceps tendon injuries are often overlooked during treatment. Therefore, it is necessary to effectively identify LHBT lesions before surgery. This study aimed to predict intra-articular lesions using preoperative shear wave elastography (SWE) to assist with subsequent treatment.

METHODS

This retrospective study included 71 patients with unilateral rotator cuff tears admitted to the hospital between September 2023 and August 2024. All patients underwent preoperative ultrasound and SWE examinations. The shear modulus of the affected side and the difference in shear modulus between the 2 sides (Δ shear modulus) were used to assess outcomes. SWE records were compared with arthroscopic findings to detect abnormalities in the intra-articular portion of the LHBT. Receiver operating characteristic curves were used to determine the optimal cut-off values of SWE measurements for discriminating intra-articular LHBT lesions.

RESULTS

Among the 71 patients, 54 had full-thickness supraspinatus tears and 17 had partial-thickness tears. Additionally, 26 cases involved infraspinatus tears and 39 involved subscapularis tears. Arthroscopic examination categorized LHBT lesions into 4 types: type I, 20 cases (normal); type II, 29 cases (frayed); type III, 17 cases (partial tear); and type IV, 5 cases (complete tear). Unilateral SWE measurements were significantly correlated with the arthroscopic classification of LHBT lesions, especially those proximal to the bicipital groove portion (ρ = -0.614). The Δ shear modulus values of LHBT proximal to the bicipital groove portion (ρ = 0.750) and within the intertubercular groove portion (ρ = 0.659) were positively correlated with the classification of LHBT lesions. The receiver operating characteristic curve identified an optimal diagnostic threshold of > 14 for distinguishing between types I and II.

CONCLUSION

Preoperative SWE values were negatively correlated with intra-articular LHBT lesions. The Δ shear modulus of the LHBT effectively predicts arthroscopic classification and accurately differentiates diseased tendons. These findings highlight the potential of SWE in preoperative assessments.