How should I evaluate and manage a patient who cannot fully extend the elbow after sustaining trauma by running into a wall with outstretched arms?

Evaluation and Management of Inability to Fully Extend Elbow After Trauma

Begin with plain radiographs of the elbow immediately, as this is the standard initial imaging for acute elbow trauma and inability to fully extend the elbow is highly sensitive for fracture. 1

Initial Clinical Assessment

The inability to fully extend the elbow after trauma is a critical clinical finding that warrants immediate attention:

• Loss of full elbow extension has 90.7% sensitivity for bony injury and should prompt radiographic evaluation 2
• Preservation of full active range of motion (flexion, extension, pronation, supination) is 97% specific for absence of fracture and 100% sensitive when any limitation exists 3
• The mechanism described (running into wall with outstretched arms) suggests axial loading injury, which commonly causes radial head/neck fractures (50% of adult elbow fractures) 1

Key Physical Examination Findings to Document

• Test active elbow extension with patient sitting, shoulders at 90° flexion - this is the validated elbow extension test 1
• Palpate for point tenderness at the radial head, olecranon, and medial/lateral epicondyles - these findings are highly sensitive for fracture 4, 3
• Assess for visible bruising - presence increases fracture likelihood 4
• Evaluate for joint effusion signs - swelling and inability to extend suggest intra-articular pathology 1

Imaging Algorithm

Step 1: Initial Radiographs (Always Appropriate)

Obtain standard elbow radiographs immediately - this is the first-line imaging modality for acute elbow trauma 1

• Look for posterior and anterior fat pad elevation on lateral view, which indicates joint effusion and implies occult fracture even if no fracture line is visible 1
• Common fracture patterns from this mechanism include radial head/neck, olecranon, and coronoid process fractures 1
• Avulsion fractures at tendon/ligament attachment sites may be present 1

Step 2: If Radiographs Are Normal or Indeterminate

If the patient cannot fully extend the elbow but radiographs appear normal, proceed with CT without IV contrast 1

• CT detects occult fractures in 12.8% of patients with positive elbow extension test and normal radiographs 1
• CT is particularly valuable for identifying radial head, olecranon, and coronoid process fractures missed on plain films 1
• CT provides critical information about fragment size, displacement, and angulation that affects surgical planning 1

Alternative: Repeat radiographs in 10-14 days if clinical suspicion is lower and patient can be safely observed 1

Step 3: If Soft Tissue Injury Is Suspected

If radiographs and CT are normal but extension limitation persists, obtain MRI without IV contrast or ultrasound to evaluate for ligamentous, tendinous, or muscle injury 1

• MRI is superior for detecting lateral collateral ligament complex injuries, medial collateral ligament tears, and tendon disruptions 1
• Ultrasound can identify triceps tendon ruptures and ligamentous injuries but has limited evidence in acute trauma 1

Management Considerations

Fracture Management

• Displaced or comminuted fractures require orthopedic consultation for potential surgical fixation 5, 6
• Timing of fracture fixation should be determined by fracture pattern and soft tissue status to allow early range of motion and minimize stiffness 5
• Radial head fractures, Essex-Lopresti injuries, and Monteggia fracture-dislocations require specific surgical approaches 1

Dislocation Assessment

• Evaluate for associated elbow dislocation or instability - coronoid fractures suggest prior dislocation with ligamentous injury 1
• Complex injury patterns include terrible triad (radial head fracture, coronoid fracture, elbow dislocation), posterior fracture-dislocation, and trans-olecranon fracture-dislocation 1

Common Pitfalls to Avoid

• Do not dismiss inability to extend as "just a sprain" - this finding has 90-100% sensitivity for significant injury 3, 2
• Do not rely solely on initial radiographs - occult fractures are common when extension is limited 1
• Do not delay advanced imaging in patients with persistent inability to extend - early CT can prevent missed fractures that lead to poor outcomes 1
• Always assess for associated soft tissue injuries when fractures are identified, particularly ligamentous disruption 1, 6