Thumb Amputations
Thumb provides 40% of hand function
- Amputation at/distal to IPJ = good function
- Through P1 = reduced function
- Loss of opposition and significantly reduced pinch and grip strength
- At/proximal to MCPJ = no function
Treatment options for proximal amputations:
- Pollicization — another functioning finger is transplanted to give thumb function
- Toe transplantation
- Metacarpal lengthening
- An option when most of MC remains (so when performing the amputation, it’s important to retain as much length as possible)
- This technique allows for a longer, more functional stump without donor site morbidity
Finger Amputations
Distal Finger:
- Preserve tendon insertions if distal to DIPJ
- If amputation being performed at DIPJ then cut tendons and allow to retract
- Don’t suture flexor tendons to extensor tendons for coverage to avoid quadriga effect which leads to a flexion lag and reduced grip strength – use skin flap instead
- Ablate entire nailbed if >2/3 gone
- Prevents nail horn formation
- Lumbrical plus deformity
- Extension at phalanges when MCPJ flexed due to intact lumbrical attachment on the extensor apparatus but loss of distal FDP attachment
Proximal Finger:
- Proximal to FDS = poor flexion
- Central digits — gap interferes with grip
- Can be more of a hindrance due to issues holding objects
- Ray amputation may be more beneficial
Ray amputation:
- Entire removal of the digit and most, if not all, of the metacarpal
- Transverse metacarpal ligament is repaired to bring the remaining metacarpals together
- Narrows the hand and can reduce grip strength, but this is balanced against the gain in a more functional grip, especially in central finger amputation where a small stump may mean objects fall through the hand when gripped
- Consider when only small stump would be left
- Amputating index finger shifts pincer grip to middle finger
Author Contributions
Page written by Dr James Drummond