Thumb fractures, and by this I mean 1st metacarpal fractures, have a couple of distinct patterns that are different from the other metacarpals.
Type I: Bennett Fracture
- This fracture is intra-articular on the ulnar side of the first metacarpal, basically making a little triangle
- It’s that little ulnar fragment that stays attached to the trapezium by the virtue of the volar ligament
- The distal aspect of the metacarpal gets supinated and dislocated radially no thanks to the adductor pollicis
- The fragment gets pulled proximally by the abductor pollicis brevis and abductor pollicis longus
Type II: Rolando Fracture
- You can think of this fracture as a really busted up Bennett’s (comminuted). It is also intra-articular and usually makes a Y or T shape
- These kind generally heal poorly but thankfully are fairly rare
Type III: Other extra-articular fractures
- This is basically any other 1st metacarpal fracture (all the extra-articular ones)
- They are the most common, but don’t have fancy names, just lame ones like “transverse“, “oblique“, etc.
- These really only exist in paediatrics and involve the proximal physis (growth plate)
Treatment: it’s best to treat Bennett and Rolando Fractures with thumb spica splints and then refer them to your friendly neighbourhood plastic surgeon or orthopaedic surgeon as they might need pinning or an open reduction.