Scaphoid Fracture

Overview

Scaphoid fracture is the most common carpal bone fracture, accounting for ~60–70% of all carpal fractures. It occurs most frequently in young adults (15–40 years) following a fall on the outstretched hand (FOOSH). The scaphoid’s tenuous blood supply predisposes to non-union and avascular necrosis, especially in proximal fractures. Early recognition is essential as delayed or missed diagnosis is common and may lead to long-term disability.

Anatomy & Physiology 

• Scaphoid: Boat-shaped carpal bone on radial side of wrist; articulates with radius, trapezium, trapezoid, capitate, lunate.
• Blood supply: Retrograde from dorsal carpal branch of radial artery → enters distally → supplies proximal pole last.
• Clinical relevance: Proximal fractures at highest risk of AVN due to poor vascularity.

Aetiology and Risk Factors

Aetiology

• Direct trauma: FOOSH (most common).
• Less common: Punching injuries, direct blow to wrist.

Risk Factors

• Young, active adults (sports injuries, falls).
• Males > females.
• High-energy trauma (e.g., motor vehicle accidents).
  

Pathophysiology 

1. FOOSH → axial load transmitted through radial styloid.
2. Scaphoid bone compressed against distal radius.
3. Fracture occurs, most often at the waist (70%), less at proximal pole (20%) or distal pole (10%).
4. Retrograde blood supply disrupted → risk of delayed healing or AVN (especially proximal).

Clinical Manifestations

• Wrist pain after FOOSH.
• Clinical examination
  • Anatomical snuffbox tenderness (classic).
  • Tenderness over scaphoid tubercle (volar wrist).
  • Pain with axial compression of thumb.
  • ↓ wrist motion, swelling may be minimal.
• Often subtle → patients may continue to use wrist.

Diagnosis

• Clinical suspicion: FOOSH + snuffbox tenderness.
• X-ray (wrist, scaphoid views): May be normal initially (up to 30% missed).
• Repeat imaging: X-ray after 10–14 days if initial negative.
• MRI (gold standard): Detects occult fractures within 24 hours.
• CT scan: Best for assessing union and fracture displacement.

Differential Diagnosis

Condition	Differentiating Features
Distal radius fracture	More swelling/deformity, visible on plain films
Wrist sprain	No bony tenderness, normal MRI
Scapholunate ligament injury	Pain on Watson’s test, widening on imaging

Classification

• Distal pole (~10%) – good healing, low risk AVN.
• Waist (~70%) – most common.
• Proximal pole (~20%) – poor healing, high risk AVN.

Treatment

• Non-displaced distal/waist fractures: Immobilisation in thumb spica cast for 6–12 weeks.
• Proximal or displaced fractures: Surgical fixation (percutaneous screw or open reduction).
• Follow-up imaging: CT/MRI for union assessment.
• Rehabilitation: Gradual mobilisation once union confirmed.

Complications & Prognosis

Complications

• Non-union (5–15%).
• Avascular necrosis (esp. proximal pole).
• Osteoarthritis (SNAC wrist – Scaphoid Non-union Advanced Collapse).
• Chronic pain, stiffness, ↓ grip strength.

Prognosis

• Good if treated early
• Poor outcomes with delayed diagnosis.

References

1. Gelberman RH, Menon J. The vascularity of the scaphoid bone. J Hand Surg Am. 1980;5(5):508–13.
   
2. Yin ZG, Zhang JB, Kan SL, et al. Diagnostic accuracy of imaging modalities for suspected scaphoid fractures: meta-analysis. BMJ. 2012;344:e3052.
   
3. Fowler JR, Hughes TB. Scaphoid fractures. Clin Sports Med. 2015;34(1):37–50.
   
4. Ibrahim T, Qureshi A, Sutton AJ, et al. Surgical vs non-surgical treatment of acute scaphoid fractures: systematic review and meta-analysis. Cochrane Database Syst Rev. 2008;(4):CD006770.
   
5. Buijze GA, Ochtman L, Ring D. Management of scaphoid fractures in adults: what’s new? Injury. 2010;41(11):1120–8.