What is the best way to evaluate a biceps tendon injury of the shoulder?

Evaluation of Biceps Tendon Injury of the Shoulder

Initial Imaging Approach

Begin with plain radiographs (at least 3 views including AP and axillary or scapular-Y) to rule out fractures and bony abnormalities, then proceed directly to MRI without contrast as the definitive imaging study for biceps tendon pathology. 1, 2

Radiographic Evaluation (First-Line)

• Obtain standard shoulder radiographs with minimum 3 views: anteroposterior (AP) in internal and external rotation plus axillary or scapular-Y view 3
• Radiographs exclude associated fractures, glenohumeral dislocation, and bony Bankart lesions that may accompany biceps injuries 3
• Upright positioning is preferred over supine to avoid underrepresenting shoulder malalignment 3

MRI Without Contrast (Definitive Study)

MRI without contrast is the most accurate imaging modality for biceps tendon tears, demonstrating 86.4% accuracy compared to ultrasound's 45.5% for complete tears. 1, 2

• MRI provides superior sensitivity (76%) and specificity (50%) for biceps tendon pathology compared to ultrasound 2
• The FABS (flexion-abduction-supination) view optimizes visualization of the distal biceps tendon 1, 2
• MRI effectively distinguishes partial from complete tears, which is crucial for treatment planning 1, 2
• MRI identifies associated pathology including rotator cuff tears and SLAP lesions that commonly accompany biceps tendinitis (present in 55.3% of cases) 4, 5

Alternative Imaging When MRI Contraindicated

Ultrasound serves as a second-line option only when MRI is contraindicated or unavailable, despite significant limitations in diagnostic accuracy. 3, 1, 2

• For long head biceps tenosynovitis specifically, ultrasound and MRI are rated equally appropriate (rating 9/9) by ACR guidelines when local expertise is available 3
• However, ultrasound has substantial limitations detecting partial tears and tendinopathy 1, 2
• The medial imaging approach is preferred when performing ultrasound evaluation 2
• Ultrasound-guided injection of anesthetic/corticosteroid can provide both diagnostic and therapeutic benefit 3

Advanced Imaging Considerations

• MR arthrography is rated equally appropriate (9/9) for post-surgical evaluation or when distinction between full-thickness and partial-thickness tears remains unclear after standard MRI 2
• MR arthrography provides superior assessment of intra-articular pathology including SLAP tears and partial rotator cuff tears compared to non-contrast MRI 3
• CT arthrography is inferior to MR arthrography for partial-thickness tears and should only be considered if MRI is contraindicated 3

Clinical Examination Limitations

Physical examination tests (Speed's, Yergason's, bicipital groove tenderness) have poor sensitivity (32-63%) and should not be relied upon alone for diagnosis. 6, 5

• Speed's test demonstrates 32% sensitivity and 75% specificity with likelihood ratio of only 1.28 6
• Yergason's test shows 43% sensitivity and 79% specificity with likelihood ratio of 2.05 6, 5
• These tests do not generate significant changes in post-test probability and cannot reliably rule out biceps pathology 6, 7
• Bicipital groove point tenderness with arm in 10 degrees internal rotation is the most common isolated clinical finding but requires imaging confirmation 4

Critical Pitfalls to Avoid

• Never rely solely on ultrasound when MRI is available, as accuracy drops from 86.4% to 45.5% for complete tears 1, 2
• Do not skip radiographs before advanced imaging, as associated fractures or dislocations alter management 1, 2
• Avoid depending on physical examination alone given poor sensitivity of provocative tests (32-63%) 6, 5
• Do not assume isolated biceps pathology without imaging assessment for rotator cuff tears (present in >50% of cases) 4, 5