TAA Flashcards
Foot consists of
tarsals
metatarsals
phalanges
Talus transfer most of the weight from…
tibia to the calcaneus
The ankle is a _ joint
hinge
What three bones form the ankle
tibia
fibula
talus
Primary weight bearing surface
distal surface of the tibia and the trochlea of the talus
3 joints that provide the stability
proximal tibiofibular joint
distal tibiofibular joint
fibulotalar joint
the ankle articular capsule ligaments
medial deltoid ligament
3 lateral ligaments
anterior + posterior portions are…
thin
lateral and medial surfaces _____ and reinforces by _____ ligaments
strong
stout
foot motion occurs about 3 axes
dorsiflexion and plantarflexion
eversion and inversion
abduction and adduction
mitered hinge model of leg
tibia internally rotates, the subtalar joint evert (eversion)
tibia externally rotates, the subtalar joint invert (inversion)
Ankle dieases
osteoarthritis, rheumatoid arthritis, fused ankle, failed TAA
Symptoms of ankle diseases
inflammation, wear of cartilage (bone on bone contact)
swelling and pain during gait + up/down stairs
joint deformation
treatments
bracing and shoe wear alterations
joint injections
ankle joint debridement
distraction
arthrodesis
arthroplasty
components of TAA
Tibial component
talar component
bearing component
bearings can be
fixed
mobile
candidates for TAA
older patients with joint problems
normal alignment of bone tissue
stability of ankle and foot
no history of septic arthritis
not very active patient
not over weight
greatest failure mode of TAA
implant loosening
-greater in constrained designs
-cemented prosthesis
Ankle arthrodesis of fusion consist of
removal of articular cartilages
internal fixation of talus and tibia
fixation of fibula is controversial
cons of ankle arthrodesis
fusion of ankle joint
increase stress in other joints (subtalar)
additional fusion
pain + arthritis in other joints
cons of TAA
wear of joint implant
material debris
loosening of implant + interface
revision often requires custom implant (bone graft)
What is TAA
Replacement of articulating surfaces (tibial and talar)
tibial comp (metal implant with short stem)
talar comp (metal articulating surface)
bearing (UHMW polymer)
studies show that the talar component….
deforms the liner, articulating with the deformed component
what is ankle arthrodesis
removal of articular cartilage
fixing the talus and tibia together
fuses the ankle joint (no movement)
