What types of disarticulation/transections are used for the foot?
- Chopart
- Lisfranc
- Transmetatarsal
- Ray resection
- Digit
Chopart
- disarticulation of mid foot from forefoot
- level of talus and calcaneus
Lisfranc
- disarticulation of forefoot (metatarsals) from mid foot (tarsals)
Transmetatarsal
- transection through length of one or more metatarsals
- usually just proximal to met heads
Ray resection
- disarticulation of one or more metatarsals and their phalanges from tarsal and neighboring metatarsals
- often requires skin graft to achieve adequate tissue closure
Digit
disarticulation at tarsal-metatarsal joint
Typical partial foot amputation pt
- 60-70 y.o.
- compromised proprioception and sensation
- weak LE musculature
pt who has weak quads: how does this impact gait?
- pt keeps knee extended during LR
- high energy cost
- slower
Main goal for foot disarticulation pts (remaining tissue)
- protect remaining tissue
- vulnerable to vascular or neuropathic disease
Prosthetic options for foot disarticulation
- neuropathic walker
- toe fillers
neuropathic walker
- locks at ankle
- custom AFO with rocker bottom
Syme’s amputation is the removal of:
- inferior projections of tib/fib
- all distal bone structures
What does a Syme’s amputation preserve?
natural WB fat pad of the heel
What is the challenge to prosthetic component selection for a Syme’s amputation?
- must encompass distal expansion of tibia firmly
- needs to still allow for donning and doffing
Alignment of Syme foot
slight DF relative to shin
Why does the Syme’s foot need to be in DF?
- mimic normal gait pattern
- encourage energy efficient rollover during stance
What would you do to Syme foot for someone who has weak quads?
reduce DF angle
Syme socket position
- positioned in angle of adduction
- matches normal adduction of tibia
