Biceps Tendon Injury: AI-Powered MRI Analysis

The long head of the biceps tendon (LHBT) is best evaluated on axial MRI sequences as it courses through the bicipital groove. Normal tendon appears as a uniformly dark round structure on T2-weighted images. Tendinopathy shows intratendinous T2 hyperintensity and tendon thickening. Tenosynovitis is identified by fluid surrounding the tendon within the bicipital groove sheath, distinct from a small amount of physiologic fluid that communicates with the glenohumeral joint. Complete rupture manifests as absence of the tendon within the groove and is confirmed by identifying the retracted tendon end. Axial T2-FS images at the level of the groove and coronal-oblique sequences at the superior labrum biceps anchor are complementary for full assessment.

The long head of the biceps tendon originates from the supraglenoid tubercle and the superior labrum, making SLAP tears and biceps anchor pathology intimately related. Traction on the biceps tendon during deceleration of the overhead throw transmits load to the superior labrum, producing type II SLAP tears at the biceps anchor — the most common type in overhead athletes. MR arthrogram with intra-articular gadolinium is the preferred study to assess both the biceps anchor and the adjacent superior labrum on coronal-oblique and sagittal sequences. Intrasubstance signal change in the proximal biceps tendon on axial images often accompanies superior labral tears. Surgical decision-making between SLAP repair and biceps tenodesis depends on patient age, activity demands, and the degree of intratendinous biceps degeneration.

Biceps tenodesis — detaching the LHBT from its superior labral origin and reattaching it to the proximal humerus — is preferred over SLAP repair in patients over 35 years of age, those with significant intratendinous biceps degeneration, workers performing repetitive forearm supination, and patients in whom the SLAP tear is associated with concurrent bicipital groove pathology. In older patients, SLAP repair carries higher failure rates and longer recovery. Tenodesis reliably eliminates anterior shoulder pain arising from the biceps-labral complex while preserving biceps function. Subpectoral or arthroscopic suprapectoral tenodesis locations each have advantages; the subpectoral approach removes the entire pathologic intertubercular segment of the tendon. SLAP repair remains preferred for young overhead athletes with isolated type II SLAP tears.