What is the appropriate management for a patient presenting with snuff box tenderness, potentially indicative of a scaphoid fracture or other wrist injury?

Management of Snuffbox Tenderness

For a patient with snuffbox tenderness following wrist trauma and normal initial radiographs, proceed directly to MRI without IV contrast rather than presumptive casting, as MRI has 94.2% sensitivity and 97.7% specificity for detecting occult scaphoid fractures and can identify concomitant ligamentous injuries that may change management. 1, 2

Initial Imaging Protocol

• Obtain standard wrist radiographs including posteroanterior, lateral, and 45° semipronated oblique "scaphoid view" as the first step 2, 3
• The dedicated scaphoid view increases diagnostic yield for both distal radius and scaphoid injuries that may be missed on standard 3-view series 3
• A minimum of 3 views is required; relying on only 2 views is inadequate and leads to missed fractures 3

Critical Clinical Context

Avoid the common pitfall of relying solely on snuffbox tenderness for diagnosis. The American Academy of Orthopaedic Surgeons warns that 80% of patients with anatomical snuffbox tenderness have no definite bony injury, leading to unnecessary immobilization 2. Research confirms snuffbox tenderness has only 40% specificity, though 90% sensitivity 4.

• Consider using a Clinical Scaphoid Score (CSS) to stratify risk: snuffbox tenderness (3 points) + scaphoid tubercle tenderness (2 points) + longitudinal thumb compression pain (1 point) 5
• A CSS ≥4 has statistical significance for predicting occult fractures and warrants advanced imaging 5
• A CSS <4 has 96% negative predictive value, making scaphoid fracture unlikely 5

Advanced Imaging When Initial Radiographs Are Normal

MRI Without IV Contrast (Preferred)

MRI is the preferred first-line advanced imaging modality. 1, 2

• Highest diagnostic accuracy with 94.2% sensitivity and 97.7% specificity for occult scaphoid fractures 1, 2
• Detects concomitant ligamentous injuries (scapholunate, lunotriquetral tears) that may affect surgical treatment 6, 2
• Can identify bone bruises, soft tissue injuries, and early avascular necrosis 1, 3
• Research demonstrates MRI changes diagnosis in 55% and management in 66% of patients with unexplained clinical symptoms 6
• In one series of 611 consecutive cases, 56% had abnormal MRI findings: 80% acute bony injuries, 8% acute soft tissue injuries, 12% incidental pathology 7

CT Without IV Contrast (Alternative)

Use CT if MRI is contraindicated, unavailable, or the patient is claustrophobic 1, 2

• Provides high-detail imaging of bone cortex and trabeculae with shorter acquisition times 1
• Easier to perform in patients already casted 1
• Particularly useful for suspected hook of hamate fractures 1
• Research shows 96.8% negative predictive value and 100% positive predictive value for all wrist fractures 8
• Nearly 100% sensitivity and specificity for detecting occult fractures 8

Imaging Modalities to Avoid

• Ultrasound is not suitable for early scaphoid fracture diagnosis with only 47-81.5% sensitivity and 61-77.4% specificity 1, 2
• Bone scan has high sensitivity but lower specificity compared to CT and MRI; may be reasonable only for claustrophobic patients 1
• IV contrast provides no added benefit for acute wrist trauma and is not appropriate 6, 1

Management Pitfalls to Avoid

• Do not delay diagnosis with the traditional "cast and repeat radiographs in 10-14 days" approach, as this leads to functional impairment 6, 3
• Do not miss concomitant ligamentous injuries that require MRI for detection and may necessitate surgical intervention 2
• Proximal pole fractures carry higher risk of avascular necrosis due to retrograde blood supply and warrant closer monitoring 2
• Worsening pain 2 weeks post-injury despite negative initial radiographs is a red flag demanding immediate MRI 3

Pending Advanced Imaging

• Avoid weight-bearing activities with the affected hand until imaging is obtained to prevent displacement of occult fractures 3
• If advanced imaging reveals scaphoid fracture or ligamentous injury requiring repair, refer to hand surgery or orthopedics 3

Rehabilitation Considerations

• Instruct patients to perform active finger motion exercises throughout cast treatment to prevent finger stiffness, which is one of the most functionally disabling complications 2