Thumb fracture

Background

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

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)

Bennett's fracture

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]

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

↑ 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.