Ankle Arthrodesis Flashcards
What are some indications for ankle arthrodesis (ankle fusion)
- post-traumatic arthritis**
- RA
- failed TAR
- Septic arthritis
- talar AVN
- Charcot neuroarthropaty
- congenital/paralytic deformities
- drop foot
- tumor with joint invasion
What are Glissan’s Principles for ankle arthrodesis
- complete removal of all cartilage
- accurate and close fitting fusion surfaces
- optimal position of the ankle joint
- maintenance of the position until fusion is complete
What is one of the main keys to a successful ankle fusion
Proper positioning
What is the optimal positioning for ankle fusion
- 0-5 degrees RF valgus
- 5-10 degrees ER
- foot 90 degrees DF to leg
Why does the RF need to be in valgus for ankle fusion positioning
- varus can lead to overloading of the forefoot and cause hindfoot symptoms
Why does the foot has to be dorsiflexed to the leg in ankle fusion positioning
- overly plantarflexed can lead to genu recurvatum
- may need to perform TAL or Gastroc recession too
What are the four surgical approaches for ankle fusion
- anterior
- lateral/trans fibular
- medial
- posterior
What are the 2 types of anterior surgical approaches for ankle fusion
- charnley transverse
- midline longitudinal
What are the differnet techniques to fusing an ankle
- in situ fusion
- articulate fusion with bone grafting/wedging
- fusion with malleolar osteotomy
- anterior arthrodesis with inlay grafting
- subtotal or incomplete resection
- arthroscopic fusion
What is in situ fusion
- fusing in the position its in
- removal of articular cartilage from talus/tibia
- used in cases with minimal deformity
What is Goldthwait bone grafting
Bone graft used to pack defect through U shaped incision
What is Hallock bone graft
Tibial bone graft
What is Chuinard and Peterson bone graft
- iliac bone graft in children
What is wescott bone graft
Graft from upper tibia
What is Campbell et al bone graft
Autogenous iliac crest graf
What is fusion with malleolar osteotomy
Medial or lateral malleolar osteotomy
- better joint exposure
- malleolus can be used as inlay strut graft
What is Horwitz fusion with malleolar osteotomy
Lateral approach with fibular osteotomy
Fibular divided longitudinally
What is Glissan fusion with malleolar osteotomy
Medial malleolar osteotomy as inlay
What is Wilson fusion with malleolar osteotomy y
Bi-hemi-malleolar approach: tibial graft medially/anterolateral fibular only
What is subtotal/incomplete resection aka Dowel fusion
- medial approach with removal of medial malleolus
- 1.5 inch bit to ream central joint
- cavity filled with bone chips
What is the angular deformity for arthroscopic fusion
Minimal - less than 10-15 degrees
What is the major benefit of arthroscopic fusion
Smaller incisions
What are some contraindications for arthroscopic ankle fuson
- excessive bone loss
- neuropathic joints
- active infection
- poor bone stock
- talar AVN
What is the mean time to union in ankle arthrodesis
12 week
What is the union rate for ankle arthrodesis
85-97%
What is the Ogilvie-Harris Screw technique for ankle arthrodesis
2 versus 3 screw technique: medial/lateral malleolus into talus and anterior from tibia to talus
What is the Hendrickx et al screw technique for ankle arthrodesis
- 2 incision/3 screw technique
- additional screw from lateral to medial
What is the Holt et al screw technique for ankle arthrodesis
- 3 screw technique
- additional posterior screw into talar neck
What is the Zwipp et al technique for ankle arthrodesis
- 4 screw technique
What is the tripod technique in ankle arthrodesis
- home run screw
- 2nd screw
- 3rd screw
What is the direction of the home run screw in tripod technique
Poseriomedial tibia to plantarlateral talar head
What is the position of the 2nd screw in the tripod technique
Medial tibia into lateral talar process
What is the position of the 3rd screw in the tripod technique
Anterolateral tibia to posteromedial talus
What are the special considerations for IM rod in ankle arthrodesis
- RA
- failed ankle arthrodesis with STJ involvement
- Charcot arthropathy
Which joint do you must fuse when using an IM rod in ankle arthrodesis
STJ
What are the different ex-fix you can use in ankle arthodesis
- 2,3,4 pin compression fixators - can create instability/hinge effect
- Ilizarov frame
- Taylor Spatial frame
- Sidekick stealth rearfoot fixators
What are some advantages of ex-fix over internal fixation for ankle arthrodesis
- better fixation of osteoporotic bone
- small bone segment fixation
- greater strength for weight-bearing
- allows for fine-tuning of residual deformity post-op
What is the goal of ex-fix in ankle arthrodesis
Symmetric joint compression
- threaded rods
- russian tensioning technique
What is the post-op course for ankle arthrodesis
- NWB until radiographic consolidation is visualized - 8-12 weeks
- transitioned to PWB in CAM walker
- When transitioned to regular shoe, patient may require heel lift/heel cushion and full length rocker sole
What are some complications of ankle arthrodesis
- delayed union/nonunion/malunion
- wound dehiscence
- infection
- adjacent joint arthritis
- painful/prominent hardware
What is the incidence of STJ and TNJ arthritis after ankle arthrodesis
STJ - 16%
TNJ - 11%
After ankle arthrodesis, patients with HbA1c >7% had a ____ fold increase of post op infection
5
After ankle arthrodesis, patients with neuropathy had a ____ fold increase risk of post op infection
21
What preoperative glucose is associated with non infectious complications
Less than 100 mg/dL
The effect of screw position and number on the time to union of arthroscopic ankle arthrodesis article showed which type of screw position and numebr was preferred
Transmedial malleolar screw fixation with 3 scews
Which approach is associated with excellent union rates, low complication rates and high levels of patient satisfaction in ankle arthrodesis
Anteromedial
