What is the differential diagnosis and recommended workup for elbow pain?

Elbow Pain: Differential Diagnosis and Workup

Begin with plain radiographs of the elbow as your initial imaging study for both acute and chronic elbow pain presentations, as this is the most appropriate first-line diagnostic test to identify fractures, dislocations, intra-articular bodies, heterotopic ossification, osteochondral lesions, and osteoarthritis. 1, 2

Differential Diagnosis by Anatomic Location

The differential diagnosis should be organized by the anatomic region of pain, as this localizes the injury effectively 3:

Lateral Elbow Pain

• Lateral epicondylitis (tennis elbow): Most common cause of chronic lateral elbow pain, affecting 1-3% of the population, caused by tendinosis of the common extensor tendon (particularly extensor carpi radialis brevis) 2, 4
• Radial tunnel syndrome: Consider when lateral epicondylitis treatment fails 3
• Cervical radiculopathy: Must be excluded in the differential 4

Medial Elbow Pain

• Medial epicondylitis (golfer's elbow): Tendinosis of the common flexor tendon origin 2, 5
• Ulnar collateral ligament (UCL) injury: Particularly in overhead throwing athletes 2, 5, 6
• Ulnar neuropathy/cubital tunnel syndrome: Common cause requiring electromyography for nerve-related symptoms 2, 5, 6
• Snapping triceps syndrome: Abnormal triceps anatomy causing medial symptoms 5, 6
• Medial antebrachial cutaneous neuropathy 5

Anterior Elbow Pain

• Biceps tendinopathy: History typically includes repeated elbow flexion with forearm supination and pronation 2, 3

Posterior Elbow Pain

• Olecranon bursitis: Can be septic or aseptic; diagnosed by history, physical examination, and bursal fluid analysis if necessary 3

Intra-articular Pathology

• Osteochondral lesions or bodies 2
• Osteoarthritis 2
• Synovial abnormalities 2

Initial Workup Algorithm

Step 1: Clinical Examination

• Lateral epicondylitis: Tenderness over lateral epicondyle with pain accentuated by wrist extension against resistance (Cozen's test) and resisted middle finger extension (Maudsley's test have high sensitivity) 3, 4
• Medial epicondylitis: Tenderness over medial epicondyle with pain on resisted wrist flexion and pronation 3, 6
• UCL injury: Valgus stress testing, particularly in overhead throwing athletes 2, 5
• Ulnar neuropathy: Tinel's sign at cubital tunnel, sensory changes in ulnar nerve distribution 5, 6

Step 2: Initial Imaging - Plain Radiographs

Radiographs are "usually appropriate" (rating 7-9) as the initial imaging study for both acute and chronic elbow pain 1, 2. They can identify:

• Fractures and dislocations (acute trauma) 1
• Intra-articular bodies 2
• Heterotopic ossification 2
• Osteochondral lesions 2
• Soft tissue calcification 2
• Osteoarthritis 2
• Valgus instability (stress radiographs may be used to detect medial joint line opening) 2

Compare with the contralateral asymptomatic elbow when asymmetry is suspected 1, 2

Step 3: Advanced Imaging When Radiographs Are Normal or Nonspecific

If radiographs are normal or nonspecific and intra-articular pathology is suspected, proceed to MRI of the elbow 2. MRI is the preferred imaging modality for:

• Chronic elbow pain evaluation 3
• Soft tissue injuries including ligaments, tendons, and cartilage 1
• Osteochondral lesions 2
• Collateral ligament tears 2

Musculoskeletal ultrasonography provides an inexpensive dynamic evaluation of commonly injured structures and is particularly useful for medial elbow pain differential diagnosis 5, 3

Electromyography (EMG) should be obtained when nerve-related symptoms suggest ulnar neuropathy or cubital tunnel syndrome 2

Special Considerations

Acute vs. Chronic Presentation

• Acute elbow pain (particularly traumatic): Focus on identifying fractures, dislocations, and acute soft tissue injuries; account for approximately 5% of emergency department visits for upper extremity injuries 1
• Chronic elbow pain: More likely epicondylalgia, overuse tendinopathy, or nerve entrapment syndromes 2

Occupational and Athletic Context

• Overhead throwing athletes: High suspicion for UCL injury and valgus instability 1, 2
• Repetitive occupational activities: Increased risk for epicondylitis (both lateral and medial) 2, 3
• Workers lifting heavy objects: Increased risk for medial elbow pathology 6

Pediatric Considerations

Children with medial elbow pain require assessment for "Little League elbow" and medial epicondyle fractures following trauma 6

Common Pitfalls to Avoid

• Do not assume lateral elbow pain is always lateral epicondylitis: If treatment fails, consider radial tunnel syndrome, cervical radiculopathy, or osseous pathology 3, 4
• Do not overlook infection: When musculoskeletal infection (osteomyelitis, septic arthritis, or soft tissue infection) is suspected, different diagnostic algorithms apply 1
• Do not skip radiographs: Even when soft tissue pathology is suspected, radiographs complement subsequent MRI examination and may reveal unexpected osseous findings 2
• Do not order advanced imaging first: CT, MRI, MR arthrography, and bone scans are "usually not appropriate" as initial imaging without preceding radiographs 2