What are the next steps for an adult patient with a history of a recent fall, now presenting with hand and thumb pain, numbness, and tingling about a month post-injury?

Hand and Thumb Pain with Numbness and Tingling One Month Post-Fall

Obtain plain radiographs of the hand and wrist immediately (minimum 3-view series: PA, lateral, and oblique), and if negative or equivocal, proceed directly to MRI without IV contrast to rule out occult fracture, ligamentous injury, and evaluate for median nerve compression. 1, 2, 3

Immediate Diagnostic Workup

Initial Imaging Protocol

• Start with plain radiographs using a minimum 3-view series (posteroanterior, lateral, and 45° semipronated oblique views) as the foundation for all hand and wrist trauma evaluation, even when presenting one month post-injury. 1, 2
• Consider adding a fourth scaphoid view to increase diagnostic yield for both distal radius and scaphoid fractures, which are commonly missed on standard 3-view series. 2
• Critical pitfall: Relying on only 2 views is inadequate for detecting wrist fractures, and even 3-view series can miss important pathology including scaphoid fractures that lead to avascular necrosis and post-traumatic arthritis if untreated. 2

Advanced Imaging When Radiographs Are Negative

• MRI without IV contrast is the superior next step when initial radiographs are negative or equivocal, with 94.2% sensitivity and 97.7% specificity for occult fractures. 2, 3
• MRI detects multiple pathologies that explain worsening symptoms including occult scaphoid fractures, bone contusions, ligamentous injuries (scapholunate or lunotriquetral tears), tendon injuries, and early avascular necrosis. 2, 3
• Worsening pain one month post-injury despite negative initial radiographs is a red flag that demands advanced imaging, as ligamentous injuries can present with normal initial radiographs but progressive pain and instability. 2

Evaluation for Nerve Compression

Carpal Tunnel Syndrome Assessment

• The combination of numbness and tingling in the hand and thumb after trauma raises concern for carpal tunnel syndrome, which can develop acutely after wrist trauma or fracture. 4, 5
• Perform the Durkan maneuver (firm digital pressure across the carpal tunnel to reproduce symptoms), which is 64% sensitive and 83% specific for carpal tunnel syndrome. 4
• Check for decreased pain sensation and numbness specifically in the thumb, index, and middle fingers (median nerve distribution), and assess for weakness of thumb opposition in severe cases. 4, 6
• The flick sign (patient shakes hand to relieve symptoms) and Phalen maneuver (wrist hyperflexion reproducing symptoms) are additional useful physical examination findings. 5

When to Order Electrodiagnostic Studies

• Obtain electrodiagnostic testing (nerve conduction studies and EMG) if symptoms persist after imaging workup or if considering surgical intervention, as these studies are approximately 80% sensitive and 95% specific for carpal tunnel syndrome. 4, 7, 5
• Electrodiagnostic studies help differentiate carpal tunnel syndrome from other compressive neuropathies including cervical radiculopathy, thoracic outlet syndrome, or ulnar nerve compression. 6
• Important caveat: Electrodiagnostic studies can have false positive and false negative results, so diagnosis should be based on the combination of history, physical examination, and electrophysiological findings. 7

Clinical Algorithm for This Patient

Step 1: Immediate Actions

• Obtain 3-view (or 4-view with scaphoid view) plain radiographs of the hand and wrist to rule out fracture or malalignment. 1, 2
• Perform focused neurologic examination including Durkan maneuver, assessment of median nerve sensory distribution, and thumb opposition strength. 4, 5

Step 2: If Radiographs Are Negative

• Proceed immediately to MRI without IV contrast rather than waiting, given the one-month delay since injury and presence of neurologic symptoms. 2, 3
• MRI will detect occult fractures (especially scaphoid), ligamentous injuries, tendon pathology, and can visualize median nerve compression or swelling within the carpal tunnel. 2, 3

Step 3: If MRI Reveals Pathology

• Scaphoid fracture or ligamentous injury: Refer to hand surgery or orthopedics urgently, as these injuries require early diagnosis to prevent chronic wrist instability and arthritis. 2
• Median nerve compression without fracture: Consider conservative management with volar splinting and possible corticosteroid injection if symptoms are mild to moderate. 4, 5

Step 4: If MRI Is Negative But Symptoms Persist

• Obtain electrodiagnostic studies to confirm carpal tunnel syndrome and determine severity for surgical planning. 4, 5
• Consider that post-traumatic carpal tunnel syndrome can occur even without visible structural injury on MRI. 5

Management Pending Imaging Results

• Avoid weight-bearing activities with the affected hand until imaging is complete to prevent displacement of any occult fracture. 2
• Initiate volar splinting in neutral position, which can provide symptomatic relief for both potential fracture and carpal tunnel syndrome. 4, 5

Common Pitfalls to Avoid

• Do not attribute symptoms solely to carpal tunnel syndrome without ruling out fracture, as occult scaphoid fractures can present with similar pain patterns and lead to devastating complications if missed. 2
• Do not delay advanced imaging for repeat radiographs in 10-14 days when neurologic symptoms are present, as this represents a more urgent clinical scenario requiring immediate definitive diagnosis. 2
• Do not order CT as the next imaging study unless penetrating trauma with foreign body is suspected, as MRI is superior for detecting both occult fractures and soft tissue injuries that impact surgical planning. 3
• Do not rely on physical examination alone to diagnose carpal tunnel syndrome, as no single physical examination test is diagnostic on its own. 7