When is a thumb x-ray (radiograph) recommended for a patient?

When to Order a Thumb X-ray

Obtain a minimum 3-view radiographic series (posteroanterior, lateral, and oblique views) immediately for any suspected thumb fracture, crush injury, or acute trauma before initiating treatment. 1, 2

Acute Trauma Indications

Suspected Fracture

• Order radiographs immediately before any treatment to detect fractures, assess rotational deformity, and guide management 1
• A 2-view examination is inadequate and will miss fractures—always obtain three views: PA, lateral, and oblique projections 1, 3
• The oblique view is critical for detecting phalangeal fractures that may be invisible on standard PA and lateral views 1, 3
• Either a PA view of the entire hand or focusing on the injured thumb alone are acceptable approaches 1

Crush Injuries

• Radiographs must be obtained before suturing any wound to identify fractures, dislocations, and foreign bodies that fundamentally alter management 1, 2
• The 3-view series is essential before proceeding with wound closure 2

If Initial Radiographs Are Negative But Clinical Suspicion Remains High

• Place the thumb in a short arm cast and repeat radiographs in 10-14 days 1, 4
• Alternatively, obtain MRI without IV contrast (sensitivity 94.2%, specificity 97.7% for occult fractures) 1, 4
• CT without IV contrast is another option, particularly useful for complex anatomy and has high diagnostic yield for phalangeal fractures including thumb fractures 1, 4

Chronic or Non-Traumatic Indications

When Radiographs Are NOT Routinely Needed

• Patients with isolated trigger thumb without a history of injury or inflammatory arthritis do not need routine radiographs 5
• In one study of 93 patients with trigger finger, no radiographic finding changed management, and 62% of radiographs were completely normal 5

When Radiographs May Be Appropriate for Chronic Symptoms

• Suspected thumb base osteoarthritis in patients with chronic pain and functional limitation 6, 7
• Radiographic features (particularly joint space narrowing and subchondral bone sclerosis) correlate with hand function in thumb base OA 7
• History of inflammatory arthritis where radiographs help document erosions, joint space narrowing, and alignment abnormalities 4

Critical Pitfalls to Avoid

• Never accept poor quality radiographs or inadequate views as a basis for treatment 3
• Lack of a true lateral radiographic view or true anteroposterior view is the most frequent reason for diagnostic errors (71% of missed/misdiagnosed fractures) 3
• An oblique view can complement the lateral view but never replace it 3
• For non-immobilized digits, instruct patients to perform active range of motion exercises regularly to prevent finger stiffness 1