Principle of Trans-Tibial Socket Design Flashcards
TT socket goals
support BW
stabilize body parts (A/P, M/L)
how many types of TT sockets
3 types
2 types of TT sockets
patellar tendon bearing socket (PTB)
total surface bearing
PTB hybrid
PTB purpose
to improve weight bearing on residuum
PTB socket contours
pressure sensitive
pressure tolerant
pressure sensitive (PTB)
relief
where does the pressure sensitive contour go (PTB)
crest of tibia
anterior distal tibia
fibular head
distal fibula
hamstring tendons
pressure sensitive tissue should be
areas that are protected or relieved
areas that are pressure or load sensitive
reliefs
pressure tolerant socket (PTB)
bulges
where does a pressure tolerant socket go (PTB)
medial flare of tibial condyles
medial/lateral tibial crest
fibular shaft
these areas weight share w/ distal end
pressure tolerant can be used to provide
areas of WBing to create pressure
what do we create in an area that is pressure or load tolerant
bulge
areas of weight bearing (PTB)
weight bearing shelf
counter pressure
weight bearing shelf (PTB)
patella tendon shelf
medial tibial flare
counter pressure (PTB)
pressure created opposite to weight bearing area
gastroc bulge on popliteal fossa (neurovascular area)
area that can be used to maintain the RL on area of WBing
socket design PTB
increase area for pressure distribution
prevents/accommodates edema
better proprioception
prosthetic position*
prosthetic position –> socket design –> PTB
5-10 degrees flexion
quads on stretch
what kind of liner could you use with PTB
pelite
foam liner and cotton socks
what do socket walls do –> PTB
stabilize muscles
acts as muscle attachment
socket walls
anterior
posterior
lateral wall
medial wall
anterior –> socket walls –> PTB
quads
WB
anterior height –> socket walls –> PTB
mid patellar
posterior –> socket walls –> PTB
hamstrings
counter pressure
posterior height –> socket walls –> PTB
PT bar
lateral wall –> socket walls –> PTB
M/L stabilization of pelvis during stance
lateral wall height –> socket walls –> PTB
femoral epicondyle
medial wall –> socket walls –> PTB
adductions
secondary weight bearing
medial wall height –> socket walls –> PTB
femoral epicondyle
how do you use total surface bearing (TBS)
conjunction w/ the silicone liner on entire RL
hydrostatic principle –> TBS
mass of limb = volume of socket
RL in contact w/ socket thru gait
socket design TBS
volume match, residual limb - socket 100% surface contact maintained
no true relief or bulges, total surface WB
lower trimlines, lighter
TBS socket liner
silicone
gel
urethane liner
a TBS socket is harder to
fabricate
TBS sockets are best
without edema
TBS socket…
decreases pain
no pressure in neurovascular area
pt has had a TT amputation and was fitted w/ a prosthesis w/ a PTB socket. As a result of walking with this leg, ideally, the greatest redness should be where?
in area of the patella tendon
original design –> HPTB
had PT bar 7 mm
what is different about the hybrid PTB
smaller or just small indentation
reliefs and bugles smaller
PTB v. TSB –> which is better to use w/ edema fluctuation
PTB
immature RL
cheaper to make –> PTB v. TSB
PTB
how many sockets are TSB
81%
how many sockets are PTB
19%
which socket has more interface and suspension choices
PTB
