What are the management and identification strategies for a middle-aged to older adult patient with a suspected biceps tendon rupture and a history of shoulder or arm strain?

Management and Identification of Biceps Tendon Rupture

Diagnostic Approach

Begin with plain radiographs (minimum 3 views: AP in internal and external rotation, plus axillary or scapular-Y view) to exclude fractures, glenohumeral dislocation, and bony Bankart lesions, followed by MRI without contrast as the definitive imaging study, which has 86.4% accuracy compared to ultrasound's 45.5% for complete tears. 1, 2, 3

Clinical Presentation

Proximal (Long Head) Biceps Rupture:

• Sudden painful tearing sensation with visible "Popeye" deformity (proximal migration of muscle belly) 4, 5
• More common than distal tears, particularly atraumatic ruptures involving the long head in 89% of cases 3
• Partial rupture of the long head with intact short head represents the most common injury pattern 3

Distal Biceps Rupture:

• Occurs in 3% of all biceps ruptures, typically in middle-aged males (40-60 years) in the dominant extremity 6, 7
• Sudden sharp pain in antecubital fossa with palpable defect after eccentric extension load 2, 6
• Insidious onset with load-related localized antecubital pain that initially subsides after warm-up but progressively worsens 2

Physical Examination Findings

• Inspection: Look for muscle atrophy, asymmetry, swelling, erythema, and visible deformity of the biceps muscle belly 2, 7
• Palpation: Well-localized tenderness that reproduces pain; ability to palpate intact tendon in antecubital fossa suggests partial tear 2, 7
• Specific tests: Biceps squeeze test and hook test for distal ruptures 6
• Functional assessment: Weakness in flexion and supination strength 6, 7

Imaging Protocol

Step 1: Plain Radiographs 1, 2, 3

• Obtain upright positioning (not supine) to avoid underrepresenting shoulder malalignment 1
• May show hypertrophic bone formation at radial tuberosity in distal ruptures 7

Step 2: MRI Without Contrast (Preferred) 1, 2, 3

• Superior accuracy (86.4%) for distinguishing partial from complete tears 1, 2
• Use FABS view (flexion-abduction-supination): patient prone, elbow flexed 90°, shoulder abducted, forearm supinated for optimal distal biceps visualization 1, 2, 3
• Demonstrates soft tissue abnormalities with high accuracy 1
• Sensitivity 76%, specificity 50% for biceps tendon tears 1

Step 3: MR Arthrography (When Indicated) 1

• Equally appropriate for post-surgical evaluation 1
• When distinction between full-thickness and partial-thickness tears is unclear 1
• Superior for assessing associated pathologies: rotator cuff tears, pulley lesions, SLAP lesions 1

Alternative: Ultrasound 1, 2, 3

• Only when MRI is contraindicated or unavailable 1, 3
• Accuracy only 45.5% for complete distal tears 1, 3
• Significant limitations in detecting partial tears and tendinopathy 2, 3
• Medial imaging approach preferred with substantial interreader agreement 1
• Can provide ultrasound-guided injection of anesthetic/corticosteroid for diagnostic and therapeutic benefit 1

Management Algorithm

Complete Distal Biceps Rupture

Early surgical anatomic reattachment is the treatment of choice to restore flexion and supination strength and endurance. 6, 8, 4, 7

• Nonoperative treatment results in loss of flexion and supination strength and endurance 6
• Surgical results are superior to conservative treatment in the vast majority of patients 8, 4
• Early anatomic reconstruction (within first 8 weeks) can restore strength and endurance 8, 7
• Surgical options include one- or two-incision techniques with various fixation methods (suture anchors, bone tunnels, endobutton, biotenodesis screws) 6
• Patients do well regardless of surgical approach or fixation method, though endobuttons have higher load-to-failure strengths biomechanically 6

Surgical Complications to Monitor: 6, 4

• Nerve injuries (particularly posterior interosseous nerve palsy) 6, 4
• Heterotopic ossification (occurs in approximately 40% of surgical cases) 8
• Postoperative fracture 6
• Tendon rerupture (rare) 4
• Complex regional pain syndrome 6
• Wound infection 6
• Radioulnar synostosis 4

Proximal (Long Head) Biceps Rupture

Conservative management is often appropriate for proximal ruptures, particularly in older or less active patients, as functional deficits are typically minimal. 5

• Diagnosis usually made on clinical grounds 5
• Left untreated can lead to functional deficits, but these are generally less severe than distal ruptures 5

Partial Ruptures

Initial conservative treatment with relative rest and oral NSAIDs, reserving surgery for failed conservative management. 2, 6

• Significantly less common than complete ruptures 6
• MRI is crucial to distinguish partial from complete tears 1, 2, 3
• Relative rest to decrease repetitive loading 2
• Oral NSAIDs 2

Chronic Tears

Surgical treatment is more challenging but can still be beneficial, often requiring tendon graft augmentation. 6, 4, 7

• Tendon retraction and poor tissue quality complicate repair 6, 4
• Tendon grafts using semitendinosus, fascia lata, hamstring, Achilles, or flexor carpi radialis successfully used for length restoration 6
• Inadequate distal biceps tendon length may necessitate augmentation 7

Postoperative Rehabilitation

Protected return of motion for first 8 weeks, formal strengthening beginning at 8 weeks, unrestricted activities including lifting by 5 months. 7

Critical Pitfalls to Avoid

• Failing to distinguish between partial and complete tears: Requires MRI, not clinical examination or ultrasound alone 2, 3
• Relying solely on ultrasound: Has significant limitations (45.5% accuracy) compared to MRI (86.4% accuracy) 1, 2, 3
• Missing associated pathologies: Rotator cuff tears, SLAP lesions, pulley lesions may contribute to symptoms 1, 2
• Delayed surgical referral for complete distal ruptures: Early anatomic reattachment (within 8 weeks) provides optimal outcomes 8, 7
• Inadequate nerve protection during surgery: Meticulous attention to posterior interosseous nerve decreases complication risk 4