Biceps Tendon Instability: From Anatomy and Function to Imaging Diagnosis

Purpose or Learning Objective: (1) To review the anatomical and biomechanical factors contributing to biceps tendon instability. (2) To discuss recent advancements in ultrasound and magnetic resonance imaging for accurate diagnosis. (3) To highlight the role of dynamic assessment in detecting subtle instability.

Methods or Background: The long head of the biceps tendon plays a crucial role in shoulder stability, running through the bicipital groove and interacting with stabilizing structures like the coracohumeral ligament and the rotator cuff. Instability occurs due to pulley lesions, subscapularis tears, or groove morphology abnormalities, commonly seen in overhead athletes and degenerative conditions. Early and precise imaging evaluation is essential to prevent chronic pain and dysfunction.

Results or Findings:

• Anatomy and pathophysiology: The long head of the biceps tendon is stabilized by the biceps pulley complex. Disruption of this system leads to subluxation or dislocation, often associated with rotator cuff and labral injuries.

• Ultrasound: High-resolution ultrasound provides real-time dynamic assessment, making it ideal for detecting intermittent biceps subluxation. Sensitivity for full-thickness long head of the biceps tendon tears is high (88%); it is lower for partial-thickness tears (27%).

• Magnetic resonance imaging and magnetic resonance arthrography: Magnetic resonance arthrography improves visualization of pulley lesions and subtle tendon displacements. Fat-suppressed T2-weighted imaging enhances detection of subclinical instability. Newer three-dimensional magnetic resonance imaging techniques provide detailed anatomical evaluation, aiding in preoperative planning.

• Computed tomography arthrography: Offers high-resolution evaluation of bony abnormalities in the bicipital groove, particularly in postoperative cases.

Conclusion: Biceps tendon instability is a clinically significant but often underdiagnosed condition. Advances in high-resolution ultrasound and magnetic resonance imaging techniques have improved detection rates, particularly when dynamic assessment is used. A multimodal imaging approach enhances diagnostic accuracy and optimizes patient management and surgical planning.

Publikationsverlauf

Artikel online veröffentlicht:
02. Juni 2025