What is the appropriate assessment and initial management of wrist trauma?

Assessment of Wrist Trauma

Initial Imaging: Standard Radiographic Protocol

Begin with a minimum 4-view radiographic series including posteroanterior (PA), lateral, 45° semipronated oblique, and scaphoid views—relying on only 2 or 3 views misses critical fractures, particularly scaphoid injuries that can lead to avascular necrosis and post-traumatic arthritis. 1

• The American College of Radiology establishes that radiographs are the most appropriate first imaging study to identify fractures, arthritis, bone tumors, and alignment abnormalities 1
• The lateral view specifically demonstrates malalignments and soft-tissue swelling that may indicate ligamentous injury 1
• Adding the fourth scaphoid view increases diagnostic yield for both distal radius fractures and scaphoid injuries beyond the standard 3-view series 1

Clinical Examination Components

Perform a systematic neurovascular assessment focusing on:

• Median nerve function: Test sensation over the thumb and first three fingers, assess thumb opposition strength, and check two-point discrimination—any deficits indicate potential acute carpal tunnel syndrome requiring immediate orthopedic consultation within hours 2
• Localized tenderness: Palpate the scapholunate joint, lunotriquetral joint, scapho-trapezio-trapezoid joint, and triangular fibrocartilage complex 3
• Dynamic stability testing: Perform Watson's test for scaphoid subluxation, assess for abnormal dorso-palmar shifts of the carpus, and provoke catch-up clunks with radio-ulnar movements of the clenched fist 3
• Vascular status: Document capillary refill and radial pulse 2

Clinical examination has 100% sensitivity for ligamentous lesions in general, though specificity is 77%, making it highly reliable for determining need for advanced imaging 3

Next Steps When Initial Radiographs Are Negative or Equivocal

If clinical suspicion remains high despite negative radiographs, proceed immediately to MRI without IV contrast rather than waiting 10-14 days for repeat radiographs—this detects occult fractures with 94.2% sensitivity and 97.7% specificity and identifies ligamentous injuries that require early intervention. 1

Equivalent Advanced Imaging Options (in order of preference):

• MRI without IV contrast: Preferred for detecting occult scaphoid fractures, bone contusions, ligamentous injuries (scapholunate, lunotriquetral), tendon injuries, and early avascular necrosis 4, 1
• CT without IV contrast: Alternative when MRI unavailable, particularly useful for hook of hamate fractures, provides high-detail bone imaging with shorter acquisition times, easier in casted patients 4, 1
• Repeat radiographs in 10-14 days: Only if advanced imaging unavailable and patient can be immobilized in short arm cast 4, 1

Specific Clinical Scenarios

Suspected Ligamentous Injury or Carpal Malalignment Without Fracture

• MR arthrography, MRI without contrast, CT arthrography, or ultrasound are equivalent appropriate options 4
• Stress views and dynamic fluoroscopy can elicit instability not visible on standard radiographs 1

Suspected Tendon Injury With Acute Fracture

• MRI without contrast or ultrasound are equivalent appropriate options for hand tendon injuries 4
• MRI has 92% sensitivity and 100% specificity for flexor tendon injuries, and 100% sensitivity/specificity for tendon re-tears after repair 4

Penetrating Trauma With Suspected Foreign Body (Negative Radiographs)

• Ultrasound is preferred: Allows better localization of radiopaque foreign bodies, assessment of tendons and vascular structures, and US-guided removal 4
• CT without contrast: Alternative with 63% sensitivity and 98% specificity for foreign bodies, superior to MRI for detecting radiopaque materials 4

Critical Red Flags Requiring Immediate Action

Worsening pain 2 weeks post-injury despite negative initial radiographs demands immediate MRI—this pattern indicates occult fracture, ligamentous tear, or early avascular necrosis that will progress to chronic instability and arthritis if missed. 1

• Decreased sensation in median nerve distribution with wrist fracture requires immediate orthopedic consultation for potential emergent carpal tunnel release—do not delay for imaging 2
• Document neurovascular status every 1-2 hours while awaiting specialist evaluation 2
• Avoid weight-bearing activities with the affected hand until occult fracture is ruled out 1

Common Pitfalls to Avoid

• Never discharge patients with persistent clinical suspicion and negative radiographs without advanced imaging or immobilization and close follow-up 1
• Do not delay specialist consultation to obtain advanced imaging when neurologic compromise is present—clinical findings take priority 2
• Missed scaphoid fractures lead to nonunion, avascular necrosis, and post-traumatic arthritis with significant long-term morbidity 1
• Untreated ligamentous injuries (scapholunate, lunotriquetral) result in chronic wrist instability and progressive arthritis 1