Musculoskeletal · Orthopedic Trauma

Scaphoid Fracture

USMLE2PANCE
7

Bets

The facts most likely to be tested

1

A scaphoid fracture typically occurs following a fall on an outstretched hand (FOOSH) in a young adult.

Confidence:
2

Physical examination reveals tenderness in the anatomic snuffbox, which is the most sensitive clinical finding.

Confidence:
3

Initial radiographs are frequently negative for a fracture in the first 24 to 48 hours following injury.

Confidence:
4

The retrograde blood supply from the radial artery makes the proximal pole of the scaphoid highly susceptible to avascular necrosis (AVN).

Confidence:
5

Patients with high clinical suspicion and negative initial imaging require thumb spica splinting and repeat imaging in 1–2 weeks.

Confidence:
6

MRI is the gold standard diagnostic modality for confirming an occult scaphoid fracture when initial X-rays are inconclusive.

Confidence:
7

Nonunion is a common and serious complication due to the precarious blood supply, often requiring open reduction internal fixation (ORIF).

Confidence:

Vignette unlocked

A 22-year-old male presents to the urgent care clinic after falling onto his outstretched right hand while playing basketball yesterday. He reports persistent dull pain in the wrist and difficulty gripping objects. On physical exam, there is localized tenderness to palpation in the anatomic snuffbox. Range of motion is limited by pain, but there is no obvious deformity. Initial wrist radiographs show no evidence of fracture or dislocation.

What is the most appropriate next step in management?

+Reveal answer

Thumb spica splinting and follow-up radiographs in 1–2 weeks

The patient has a high clinical suspicion for a scaphoid fracture despite negative initial X-rays; therefore, immobilization in a thumb spica splint is required to prevent displacement and nonunion while awaiting follow-up imaging.

Mo

Depth

Full handout

High yield triage

Etiology / Epidemiology

Most common carpal fracture, typically occurring in young males following a FOOSH injury.

Clinical Manifestations

Pain in the anatomical snuffbox with tenderness to palpation and axial loading of the thumb.

Diagnosis

Initial X-ray may be negative; MRI is the gold standard for occult fractures.

Treatment

Thumb spica splint is mandatory for suspected fractures even with negative initial imaging.

Prognosis

High risk of avascular necrosis due to retrograde blood supply; non-union is a major concern.

Full handout

Epidemiology & Etiology

Commonly seen in young, active adults following a fall on an outstretched hand (FOOSH). It is the most frequently fractured carpal bone. High-impact sports and motor vehicle accidents are primary mechanisms.

Pertinent Anatomy

The scaphoid spans the proximal and distal carpal rows. Its blood supply enters distally, making the proximal pole highly susceptible to ischemia.

Pathophysiology

Fractures typically occur at the waist of the scaphoid. Because the blood supply is retrograde, a fracture disrupts flow to the proximal segment. This creates a high risk for avascular necrosis and non-union if not immobilized promptly.

Clinical Manifestations

Patients present with pain localized to the anatomical snuffbox. Tenderness to palpation in this area is highly sensitive. Pain with axial loading of the thumb is a classic clinical indicator. Always assess for associated distal radius fractures.

Diagnosis

Initial evaluation requires X-ray (AP, lateral, and scaphoid views). If initial films are negative but clinical suspicion remains high, MRI is the gold standard for diagnosis. Do not wait for callus formation on X-ray to confirm.

Treatment

Suspected fractures require immediate immobilization in a thumb spica splint. Avoid casting the entire hand to maintain function. If the fracture is displaced or non-union occurs, ORIF is required. Follow-up imaging is essential to monitor healing.

Prognosis

The primary complication is avascular necrosis (AVN) and non-union. Delayed diagnosis significantly increases the risk of long-term scapholunate advanced collapse (SLAC wrist).

Differential Diagnosis

De Quervain tenosynovitis: positive Finkelstein test

Distal radius fracture: visible deformity on X-ray

Triquetral fracture: dorsal ulnar wrist pain

Carpometacarpal arthritis: chronic pain with grinding

Radial styloid fracture: pain proximal to the snuffbox