Forearm Fracture

Aka: Forearm Fracture, Midforearm Fracture, GRUM Mnemonic, Radius Fracture, Ulna Fracture, Radius and Ulna Fracture, Mid-Shaft Radius Ulna Fracture, Nightstick Fracture

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II. Definitions

  1. Forearm Fracture
    1. Mid-shaft Fracture of the radius and/or ulna

III. Epidemiology

  1. Forearm Fractures (radius and/or ulna) are the most common Fractures of the upper extremity
  2. Distal Forearm Fractures (esp. Distal Radius Fracture) are most common
    1. Distal Radius Fractures peak age distribution is bimodal age (age <18 years and age >65 years)

IV. Mechanism

  1. Fall on an outstretched hand (axial loading) is the most common mechanism of Forearm Fracture
  2. Isolated midshaft Ulna Fracture may be sign with direct blow (Nightstick Fracture)
  3. Midshaft combined Radius and Ulna Fractures are typically high energy injuries (e.g. MVA, Sports Injury)
    1. Concurrent Soft Tissue Injury is common (as well as neurovascular injury)

V. Types: Distal Forearm and Wrist Fractures

  1. See Distal Radius Fracture
  2. See Wrist Injury
  3. Colles Fracture
    1. Distal Radius Fracture (often with ulnar styloid Fracture)
    2. "Dinner fork" deformity (distal fragment angulated dorsally)
  4. Smith's Fracture
    1. Distal Radius Fracture with displacement towards volar aspect
    2. Opposite of Colles Fracture
  5. Children
    1. See Radial Epiphyseal Fracture
    2. Forearm Buckle Fracture (or Torus Fracture)
      1. Incomplete compression Fracture resulting in cortical bulging without cortical disruption
      2. Distal radius (and/or ulna) metaphysis Fracture with tenderness and minimal to no deformity
    3. Greenstick Forearm Fracture or complete Radius Fracture
      1. Similar to Buckle Fracture, but with cortical disruption on one side of Fracture
      2. Cortical disruption is seen on tension side of the Fracture (differentiates from buckle Fracture)
      3. Bulging is seen on compression side of Fracture (similar to buckle Fracture)

VI. Types: Radius and Ulna Shaft Fractures

  1. Combined Ulna and Radius Mid-Shaft Fractures
    1. Typically require open reduction and internal fixation (ORIF)
    2. Risk of combined Fracture-dislocations (see GRUM below)
  2. Isolated Ulna mid-shaft Fracture
    1. Exclude associated Monteggia Fracture (see below)
    2. Typically occurs from fall or direct blow (e.g. Nightstick Fracture)
  3. Mnemonic: GRUM (from distal radius to proximal ulna)
    1. orthoForearmFxDislocate.jpg
    2. GR: Galeazzi - Radius Fracture
      1. Distal Radius Fracture AND
      2. Lateral dislocation of the distal ulna injuring the Ulnar Nerve
    3. UM: Ulna Fracture - Monteggia
      1. Ulna shaft Fracture AND
      2. Displaced proximal radius, injuring the Radial Nerve (Wrist Drop)
  4. Galeazzi Fracture
    1. Fracture of the distal shaft of radius
    2. Dislocation of Distal radio-ulnar joint (ulna will appear medially displaced at the wrist)
      1. Risk of Ulnar Nerve injury
  5. Monteggia Fracture
    1. Proximal Ulna Fracture of shaft (typically displaced)
    2. Proximal Radial Head Dislocation
      1. Risk of Radial Nerve injury (e.g. thumb extension weakness)

VII. Types: Proximal Forearm and Elbow Fractures

  1. Supracondylar Fracture of Humerus (most common in children)
  2. Radial Head Fracture (most common in adults)
    1. Posterior arm splint for first 7 days
    2. Transition to sling use for total of 2-3 weeks
    3. Refer to orthopedics Mason 4, 3 (and possibly 2) Fractures

VIII. Exam

  1. See Hand Neurovascular Exam
  2. See Elbow Exam
  3. Injury exam mantra: "joint above, joint below, circulation, motor function and Sensation, skin and compartments"
  4. Evaluate for open Fracture
  5. Evaluate for Ecchymosis, deformity, shortening, rotation
  6. Evaluate wrist and elbow range of motion
  7. Evaluate elbow collateral ligaments with varus and valgus testing

IX. Signs

  1. Localized Ecchymosis, swelling and tenderness at Fracture site
  2. Painful dorsiflexion has highest Test Sensitivity (>95%) for wrist Fracture
  3. Localized Ecchymosis has highest Test Specificity (>97%) for wrist Fracture
  4. Forearm may be shortened and displaced
  5. Pain may also be worse with wrist pronation
  6. Range of motion painful and diminished near the Fracture (elbow or wrist)

X. Complications

  1. High rate of non-union in adults
  2. Risk of unstable Fractures even when initially non-displaced and despite external immobilization
  3. Radial Head Dislocation in proximal ulnar Fracture (Monteggia Fracture)

XI. Imaging

  1. Radius-Ulna Anteroposterior and Lateral XRay
    1. Should show entire Forearm including wrist and elbow
  2. Oblique XRay of elbow or Wrist
    1. Evaluates Fracture extent, angulation and Fracture displacement
  3. Musculoskeletal Ultrasound of Forearm (Bedside Ultrasound, POCUS) has high accuracy in distal Forearm Fracture
    1. Test Sensitivity: 97%
    2. Test Specificity: 95%
    3. Douma-Den (2016) PLos One 11(5):e0155659 +PMID:27196439 [PubMed]
  4. CT or MRI Elbow or Wrist
    1. Consider when other imaging is negative, but reduced range of motion (e.g. elbow extension)

XII. Indications: Orthopedic Referral

  1. Orthopedic referral is indicated in most cases (aside from non-displaced or buckle Fractures)
    1. Allowable angulation and displacement is specific for each Fracture
  2. Distal Radius Fractures
    1. Fracture-dislocation
    2. Carpal Fracture
    3. Ulnar styloid Fracture
    4. Unstable Fracture or significantly comminuted
    5. Radiocarpal or radioulnar ligament injury or instability
    6. Fracture nonunion
    7. Epiphyseal Fracture suspected (children)
  3. Combined Mid-Shaft Radial-Ulnar Fractures
    1. Most will require surgery and nearly all should be referred
    2. Fracture angulation, shortening, rotation or significant comminution
    3. Combined Fracture-Dislocations (Galeazzi Fracture or Monteggia Fracture)
  4. Isolated Ulnar mid-shaft Fractures
    1. Concurrent radius, wrist or Elbow Injury
    2. Significant comminution
    3. Proximal Ulna Fracture
    4. Fracture diaphysis displacement >50% bone diameter
    5. Fracture angulation >10 degrees
  5. Radial Head Fracture
    1. Mason Type 4, 3 (and possibly 2) Fractures

XIII. Management: General

  1. Evaluate for Emergent Orthopedic Conditions
    1. Neurovascular Injury
    2. Open Fractures
    3. Compartment Syndrome
  2. Acute Fracture Management
    1. Acute Pain Management
    2. External Fracture reduction under Anesthesia as indicated
    3. Splint for 5-7 days, typically followed by Casting
      1. Maintain a low threshold for Splinting when Fracture is suspected but not seen on initial XRay
    4. Orthopedic referral indications
      1. See above

XIV. Management: Non-Mid-Shaft Fractures

  1. See Mid-shaft Radius-Ulna Fracture management as below
  2. See Distal Radius Fracture
  3. See Radial Head Fracture
  4. See Radial Epiphyseal Fracture
  5. Forearm Buckle Fracture (children)
    1. Treated with short-arm splint, then Casting for total immobilization of 3 weeks
      1. Removable splint or nonrigid immobilization are reasonable alternatives
      2. Handoll (2018) Cochrane Database Syst Rev (12): CD012470 +PMID:30566764 [PubMed]
    2. Repeat Xray has been historically performed at 3 week follow-up visit
      1. However, some guidelines recommend follow-up imaging only for persistent symptoms or signs
      2. Riera-Alvarez (2019) J Pediatr Orthop B 28(6): 553-4 +PMID:32694434 [PubMed]
      3. Ling (2018) Radiol Res Pract +PMID:29686900 [PubMed]
  6. Forearm Greenstick Fracture (children)
    1. Greenstick Fractures share the same treatment as complete non-displaced Radius Fractures
      1. Short-arm splint, then Casting for total immobilization of 3 weeks
    2. Allowable deformity without reduction (closed or ORIF) in age <10 years old
      1. Angulation <20-30 degrees (sagittal alignment, lateral XRay)
      2. Displacement <50%
  7. Distal Radius Fracture (adults)
    1. See Distal Radius Fracture
    2. External Fracture reduction under Anesthesia as needed
    3. Splint with sugar-tong for first 5-7 days
      1. Transition to Short Arm Cast for 3-6 weeks

XV. Management: Adults with Midshaft Radius-Ulna Fractures

  1. Displaced mid-shaft radius-Ulna Fractures
    1. May attempt closed reduction in emergency department under Anesthesia
    2. Sugar-Tong splint
    3. Orthopedic referral within 48 hours
    4. Open reduction and Internal Fixation (ORIF)
      1. Often indicated for displacement, shortening, angulation, rotation, comminution or instability
      2. Length of immobilization is shorter after ORIF as well
    5. Repeat Hand Neurovascular Exam before and after any manipulation or Splinting
  2. Non-displaced Midshaft radius-Ulna Fractures
    1. Initial long-arm Splinting for first 5-7 days
    2. Transition to Long Arm Cast with elbow at 90 degrees for 8-12 weeks
    3. Orthopedic referral if indicated as above
  3. Isolated Ulna Fracture
    1. Exclude Monteggia Fracture
    2. External Fracture reduction under Anesthesia as needed
    3. Splint with sugar-tong or posterior ulnar gutter for first 7-10 days
      1. Repeat XRay weekly for first 2-3 weeks
      2. Transition to Short Arm Cast or functional brace for 4-6 weeks
    4. Allowable deformity without surgery
      1. Fracture isolated to the ulna diaphysis middle or distal third
      2. Displacement <50% of bone diameter
      3. Angulation <10 degrees

XVI. Management: Children with Radius-Ulna Fractures

  1. Surgical intervention rarely needed
  2. Reduction Technique
    1. Anesthesia
    2. Angulated Fractures
      1. Traction and Counter traction
      2. Greenstick Fractures
        1. Often require breakage of opposite cortex
        2. Prevents re-angulation in cast
    3. Displaced Fractures
      1. Traction and Counter traction
      2. Slight bayonet apposition is acceptable
      3. Alignment must be satisfactory
  3. Immobilization in Long Arm Cast for 7-8 weeks
    1. Elbow flexed to 90
    2. Mold Forearm to avoid interosseus encroachment

XVII. Management: Follow-up

  1. Examine at weekly intervals for 3 weeks
  2. Inspect for re-angulation
    1. Angulation under 2 weeks
      1. Correct angulation manually
    2. Angulation over 2 weeks
      1. Angulation may be permanent

XVIII. References

  1. Bhandari (2004) J Orthop Trauma 18(7): 473-5 [PubMed]
  2. Black (2009) Am Fam Physician 80(10): 1096-102 [PubMed]
  3. Patel (2021) Am Fam Physician 103(6): 345-54 [PubMed]

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