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My Ankle Fusion Hurts: Can You Convert it to
Replacement?
Bruce Cohen, MD
OrthoCarolina Foot and Ankle Institute
Charlotte, NC
Disclosures
Wright Medical- Royalty, consulting
Amniox medical- consulting, research support
DJO- royalty
Arthrex- royalty
Why Consider?
Painful fusion Subtalar/TN disease
Malunion
Fusion non Unions
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Why Consider?
Painful fusion Subtalar/TN
disease
Why Consider?
Painful fusion Malunion
Why Consider?
Fusion Non Union
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Why Consider?
Easier then a fusion
Case
67 YO with 9 year history of good function after ankle fusion
2008
Case
67 YO with 9 year history of good function after ankle fusion Now pain in subtalar joint
2011
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Case
67 YO with 9 year history of good function after ankle fusion Now pain in subtalar joint
Options??? TTC
More injections
Conversion to a TAR: 3 years
Literature: Agility
Clin Orthop Relat Res. 2004 Jul;(424):80-8. Takedown of ankle fusion and conversion to total ankle replacement.Greisberg J, Assal M, Flueckiger G, Hansen ST Jr
19 ankles in 18 patients at an average followup of 39 months
3 Amputations
16 did OK Best results if had a definable cause of pain
E.g. subtalar pain
No fibula bad
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Literature: Mobile Bearing
J Bone Joint Surg Am. 2009 Apr;91(4):850-8.Conversion of painful ankle arthrodesis to total ankle arthroplasty.Hintermann B, Barg A, Knupp M, Valderrabano
30 painful ankles in 28 patients (average age, 58.2 years) minimum of thirty-six months (average, 55.6 months)
Twenty-four patients (82.7%) were satisfied with the results
5 ankles were completely pain-free 21 ankles were moderately painful 3 remained painful.
Pre Op Planning
Joint level CT Helps
Malleoli
Estimate the gutters
Subtalar fusion???
Reasons not to do a subtalar fusion
40% Non Union Rate
Can do it later if you need to
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5 years post scope fusionSubtalar pain
Rotation based on best guess mortise
Size to spare medial mal and talus
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If no malunion can perform coupled cut
Tibial Trial
Med Mal Size??
Talus Same
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Gutters key
10 Weeks Medial Mal Stress Fx
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2 years post op HO
5 years post op
What About Non Unions?
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52 yo
MVA
Tibia fx, med malleolus fx
Delayed healing at tibia
Eventually healed tibial shaft
Progressive collapse and DJD at ankle
Ankle fusion
Developed nonunion
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Revised with anterior plateBone graftBone stimulator
9 months s/p revision fusion
What are our options???
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5 patients Average age at conversion: 62.2 years old
Average time between attempted fusion and conversion: 1.74 years
Prospectively evaluated at a minimum of 12 months from surgery (average follow-up: 21.3 months)
INBONE® total ankle replacement (Wright Medical Technologies, Inc. Arlington, TN )
Fixed bearing implant Intramedullary implant
Results Complications:
No intraoperative complications requiring additional procedures 1 post-op complication: wound excoriation that resolved with local wound care
AOFAS ankle-hindfoot score Average: 82.6 Range: 66-90
Foot Function Index Average: 28.2% Range: 7-49%
VAS pain levels Average: 31.1/100 Range: 16.2- 44.3
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Results
4/5 very satisfied or satisfied with surgery 1 dissatisfied patient has rheumatoid arthritis and
takes daily narcotics because of her disease
5/5 would have the operation again
No evidence of tibial/talar loosening or talarsubsidence in any case at final follow-up
Is there a better way?
Case: DA. 9 years after a Successful Fusion
62, F
Hx: s/p R ankle fusion, pain
Dx: Right subtalar/ TN DJD, painful fusion
Better with injections but after 4 injections no good
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Case DA
Case DA
Case DA: Prophecy CT Guided
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Case DA
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Challenges
Gutters/ Stiffness
Challenges
Muscle atrophy
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Challenges
Malleoli
Challenges: Malleoli
Protect
Challenges: Subtalar Joint
2 Years After ConversionNO Subtalar complaints
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Challenges: Heterotopic Ossification
6 Weeks Post Op 2 Years Post Op
Challenges: Heterotopic Ossification
Challenges
Axis of rotation
Joint line
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Is there a role for Fusion to TAR in 2016?
Yes
Need longitudinal data
Cautious Optimism
Go Anterior with fusion
Leave the malleoli when you fuse
Protect the malleoli when do TAR
Prophecy
