The correct care of thumb injuries is very important. They are the way we interact with the world and problems with the thumb can have massive implications on occupation and ability to look after yourself. You need to be aware of the anatomy, common injuries and their management if you are going to reduce morbidity
2. “You can't shake hands with a clenched fist”
- Indira Gandhi
• 9 individual muscles, which are controlled by all 3 major hand nerves
3. Testing Motor Function
• “Thumbs up!” = Thumb Extension = Radial Nerve
• “Okay sign” = Flexor Pollicus Longus + Flexor Digitorum Profundus =
Median Nerve
• Normal = Flex both Abnormal = Unable to
• Thumb Opposition = Opponens Pollicus = Median Nerve
• “Fingers crossed” (Index + Middle) = Ulnar Nerve
• Froment’s Sign = Ulnar Nerve Palsy
= weak Adductor Pollicus
= Flex Flexor Pollicus Longus to
compensate to pinch rather than grip
4. Bennett’s Fracture
• Most common fracture
• Intraarticular at base of 1st metacarpal
at Carpometacarpal joint (CMC)
• Usually associated subluxation or
dislocation due to unopposed APL action
• Most will need surgical fixation
• Thumb Spica
5. Rolando Fracture
• Technically a 3 part fracture but commonly used to describe all
comminuted thumb metacarpal base fractures.
• Worse prognosis
• Thumb Spica
6. Ulnar Collateral Ligament Injury
• Also known as “Gamekeepers or Skiers Thumb”
• Due to forced abduction of the MCP joint
• Can be torn partially or fully and there can be an associated avulsion
fracture of the volar base of the proximal phalanx
• If no fracture check for stability of joint
• Thumb Spica
7. de Quervains Tenosynovitis
• Stenosing tenosynovitis of APL & EPB tendons
at the styloid process of the radius;
- inflammation causes thickening & stenosis
of synovial sheath
- most common in women between 30 - 50 yrs
• Finklestein Test
• Thumb Spica
8. Mallet Thumb
• Usually occurs due to forceful flexion of the interphalangeal joint.
• Avulsion of the extensor tendon causing the thumb to be stuck in
moderate flexion
• Mallet Splint
