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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