Thumb fracture

Background

Thumb fracture classification

  • Type I (Bennett's fracture)
    • Fracture-dislocation of the base of the metacarpal (intra-articular)
    • Base fragment is aligned with trapezium, but distal portion is subluxed by abductor pollicis longus
    • Most common type of thumb fracture; nearly always accompanied by some subluxation or dislocation of CMC
  • Type II (Rolando's fracture)
    • Comminuted version of a Bennett's fracture (intra-articular)
  • Type III
    • Extra-articular (transverse or oblique)
  • Type IV
    • Extra-articular pediatric fracture involving the proximal physis

Clinical Features

  • Important to distinguish tenderness at base of 1st MC from injury to scaphoid, trapezium, or distal radius
  • If pain or ecchymosis occurs more distally at the MCP (particularly on the ulnar side) consider ulnar collateral ligament injury (Gamekeeper's Thumb)

Differential Diagnosis

Hand and Finger Fracture Types

Evaluation

Bennett's fracture
  • Imaging plain films
    • AP, lateral, oblique

Management

General Fracture Management

  • Acute pain management
  • Open fractures require immediate IV antibiotics and urgent surgical washout
  • Neurovascular compromise from fracture requires emergent reduction and/or orthopedic intervention
  • Consider risk for compartment syndrome
  • RICE
    • Significant swelling or overly aggressive icing to radial side of thumb may result in temporary palsy to the superficial radial nerve (numbness over the dorsum of the thumb)

Acute Reduction

  • Indicated for angulated (more than 20-30 degrees), extraarticular fracture if clinician is comfortable with the procedure[1]

Immobilization

Disposition

  • Refer within 3-5 days:
    • All intraarticular fractures warrant referral (most require surgery)
    • Extraarticular fractures that cannot be adequately reduced

See Also

References

  1. German C. Hand and wrist emergencies. In: Bond M, ed. Orthopedic Emergencies: Expert Management for the Emergency Physician. Cambridge: Cambridge University Press; October 31, 2013.