Talar AVN Flashcards
What kind of cartilage covers the talus?
hyaline cartilage (covers about 60%)
what are the 3 main branches of the blood supply to the talus?
- posterior tibial artery
- dorsalis pedis artery
- perforating peroneal artery
which artery gives off the artery of the tarsal canal?
posterior tibial artery
what supplies blood to the talar head and neck?
artery of tarsal canal artery of sinus tarsi
what supplies blood to the talar body?
deltoid artery
what artery gives off the deltoid artery?
artery of tarsal canal
what is the artery of sinus tarsi formed by?
anastomosis of perforating peroneal artery and lateral tarsal artery
what is the most common cause of non-traumatic AVN?
glucocorticoid administration
how does glucocorticoid administration cause AVN of the talus?
-fat embolism from the liver or marrow fat cell
what is the classification system for talar neck fx?
Hawkin
Describe the Hawkins classification.
Hawkins 1- nondisplaced vertical neck fx
Hawkins 2- vertical neck fx + displacement of STJ
Hawkins 3- vertical neck fx with displacement of STJ and ankle joint
Hawkins 4- neck fx with displacement of STJ, ankle joint, and TNJ
what is the incidence of AVN for each Hawkins fracture?
Hawkins 1- (AVN 0-10%)
Hawkins 2- (up to 42%)
Hawkins 3- (up to 91%)
Hawkins 4- (100% AVN)
what is the hawkins sign?
(indicative of talar REVASCULARIZATION!)
This is a subchondral radiolucent line along the superior aspect of the talar dome. This indicates blood suppy to the talus reflecting disuse osteopenia and AVN IS NOT present
conservative treatment for talar AVN?
- limited or NWB
- HBO adjunct therapy
- bracing (hinged, PTB)
surgical interventions for talar AVN?
- arthroscopic debridement with core decompression
- vascularized allografts
- TTC fusions
- TC fusion with talectomy
