Thumb fracture

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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 Fractures

Evaluation

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

Management

  • Splinting
    • Type I, II - Thumb Spica Splint with the IP joint free and wrist in 30 deg of extension
    • Type III - Short arm Thumb Spica Splint extending to the IP joint and wrist in 30 deg of extension
  • 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)
  • Reduction
    • Indicated for angulated (more than 20-30 degrees), extraarticular fracture if clinician is comfortable with the procedure[1]

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.