II. Epidemiology

  1. Scaphoid is most common Carpal BoneFractured
  2. Represents 5% of all wrist injuries
  3. Usually occurs as a Workplace Injury or sports injury
  4. Most commonly affects males 18-40 years old
    1. With aging, distal radius is weaker and more commonly Fractured
  5. Rarely occurs in young children
    1. Scaphoid protected by supportive cartilage in young children
    2. Distal Radius Fracture or physeal Fractures are more common

III. Mechanism

  1. Scaphoid and Lunate Bones are only wrist bones with articulation with radius
    1. Fall on an outstretched hand transmits force to the Scaphoid Bone (and Lunate Bone)
  2. Fall on Outstretched Hand
    1. Exacerbated by wrist dorsiflexion
    2. Exacerbated by wrist radial deviation

IV. Complication

  1. Primary: Blood supply enters distal portion of Scaphoid
    1. Avascular Necrosis of proximal fragment
    2. Fracture Non-union
  2. Secondary to non-union or avascular necrosis
    1. Decreased grip strength
    2. Decreased range of motion
    3. Ostearthritis of radiocarpal joint

V. Symptoms

  1. Dorsal radial Wrist Pain
    1. Deep, dull ache
  2. Provocative factors
    1. Wrist extension
    2. Gripping or squeezing objects with pain and loss of strength

VI. Signs

  1. See Wrist Exam
  2. Diagnosis may be difficult (no obvious deformity)
  3. Keep high level of suspicion in "Wrist Sprain"
  4. See Scaphoid Fracture Signs
    1. Anatomic Snuffbox Tenderness (wrist ulnar deviated)
    2. Scaphoid Tubercle Tenderness (wrist in extension)
    3. Pain on axial pressure of First Metacarpal bone
    4. Decreased grip strength

VII. Differential Diagnosis

  1. Injury
    1. See Fall on Outstretched Hand
    2. Distal Radius Fracture (e.g. Colles Fracture)
      1. Radius is weaker than Scaphoid in young and elderly
    3. Scapholunate Dissociation (or Scapholunate Tear)
      1. Scapholunate widening >3 mm
    4. Carpometacarpal Dislocation
      1. Carpometacarpal widening >1-2 mm
    5. Lunate Fracture
  2. Wrist Overuse (i.e. De Quervain's Tenosynovitis)
  3. Arthritis (e.g. Rheumatoid Arthritis)

VIII. Imaging

  1. Wrist XRay
    1. Standard Views: AP and lateral view, obliques
    2. Scaphoid view
      1. Anteroposterior view (dorsal-volar angle)
      2. Supination to 30 degrees
      3. Ulnar deviation
    3. Test Sensitivity: 86% (variable)
      1. Tiel-van Buul (1993) J Hand Surg 18:403-6 [PubMed]
    4. Timing of XRay
      1. Normal initially in non-displaced Fracture
        1. Thumb Spica Cast if clinical suspicion
        2. Repeat Wrist XRay in 10-14 days (bony sclerosis not evident until that time)
      2. Fracture visible in 2-4 weeks with decalcification
  2. Advanced Imaging: Wrist Bone Scan or Wrist MRI
    1. Indications
      1. High clinical suspicion and
      2. Negative Wrist XRay at 2 weeks
    2. Efficacy: Bone Scan
      1. Test Sensitivity: 100%
      2. Test Specificity: 75%
    3. Efficacy: MRI
      1. Test Sensitivity: 80% on first day following injury
      2. Efficacy matches Bone Scan by Day 10

IX. Course

  1. Delayed immobilization 1-2 weeks risks non-union
  2. Radial artery supply impacts healing time
    1. Proximal Scaphoid Fracture (15%)
      1. Greater risk of avascular necrosis
      2. Nondisplaced Fractures heal in over 12 weeks
    2. Middle Scaphoid Fracture (75-80%)
      1. Nondisplaced Fracture heals in 8-10 weeks
    3. Distal Scaphoid Fracture (5-10%)
      1. Nondisplaced Fracture heals in 8-10 weeks

X. Management: Algorithm

  1. High Clinical Suspicion without radiological evidence
    1. Apply Thumb Spica Splint for 2-3 weeks
    2. Repeat Wrist XRay after 2-3 weeks
  2. Scaphoid Fracture on initial or follow-up Wrist XRay
    1. Nondisplaced distal pole Fracture
      1. Short arm Thumb Spica Cast for 6 weeks
      2. Consider not including thumb in cast (nondisplaced)
        1. Clay (1991) J Bone Joint Surg 73:828-32 [PubMed]
    2. Proximal pole Fracture
      1. Long Arm Cast for 8-12 weeks
    3. Middle third Fracture
      1. First: Long Arm Cast for 6 weeks
      2. Next: Short arm thumb spica for 2-4 more weeks
        1. Repeat Wrist XRay every 2-4 weeks
        2. Continue immobilization until union by Wrist XRay
    4. Displacement of Fracture fragments
      1. First: Long Arm Cast for 6 weeks
      2. Next: Short Arm Cast for an additional 6 weeks

XI. Management: Immobilization Techniques

  1. Thumb Spica Splint
  2. Thumb Spica Short Arm Cast
    1. Neutral position
    2. Hand in position as if holding can
  3. Long Arm Cast

XII. Prognosis

  1. Delayed healing or non-union in 5% Scaphoid Fractures

XIII. Orthopedic referral indications

  1. All proximal third Fractures
    1. High risk for nonunion
    2. High risk avascular necrosis
  2. Displaced Fractures (>1mm gap)
  3. All Angulated Scaphoid Fractures

XIV. Follow-up

  1. Days 1-2: Cast follow-up by phone or clinic visit
    1. Is cast too tight?
  2. Cast Removal
    1. Wrist XRay repeated
    2. Re-apply cast for 2-4 weeks if Fracture line visible
    3. Refer if Fracture line seen after additional Casting

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