Total Ankle Replacement
Selene G. Parekh, MD, MBAAssociate Professor of Surgery
Partner, North Carolina Orthopaedic ClinicDepartment of Orthopaedic Surgery
Adjunct Faculty Fuqua Business SchoolDuke University
Durham, NC919.471.9622
http://seleneparekhmd.comTwitter: @seleneparekhmd
Why a Total Ankle Arthroplasty?
Severe painful post-traumatic osteoarthritis
Comparison of Health-Related Quality of Life Between Patients with
End-Stage Ankle & Hip ArthrosisJBJS Mar 2008; 90:499-505
• End stage ankle arthritis is as severe, if not worse, than end
stage hip disease.
Why a Total Ankle Arthroplasty?
• The Need for Other Surgical Options:» Debilitating pain» Patients with large bone loss» Subtalar and/or midtarsal arthrosis» Bilateral involvement
• Other Advantages:» Provides pain relief» Preserves joint motion & stability
Ankle Replacement
Ankle Replacement
Varus Ankle
Valgus Ankle
Total Ankle Replacement
• USA Data
• 2,300 – 4,000 TAA done in 2010
• 20,000 – 23,000 Fusions in 2010• 96 % limp• 15% < 4 yrs. develop subtalar arthritis• 77 % satisfaction
Evaluation
• History• Reason for DJD• Prior treatments
• NSAIDS• Bracing• PT• CST injections
• Prior surgeries• Open injuries• Infection
Examination
• Gait• Alignment
• Hip knee ankle foot• Varus/valgus
• Areas of tenderness• Associated pathologies
• NV status• Sensory status• Prior incisions
Radiographic Evaluation
• Weightbearing• AP/lat/oblique
Radiographic Evaluation
• Weightbearing• Saltzman• Foot films
• AP/lat/oblique
Selection of Implant
TAR: What Went Wrong?
• 1st generation problems• Did not respect
• Anatomy• Kinematics• Alignment• Stability
TAR: What Went Wrong?
• 1st generation problems• Excessive bone resections• Changed in level of the ankle axis• Constrained design• Poor cement fixation in fatty bone marrow• Multi-axial design relied on ligaments
TAR: What Went Wrong?
MAYO prosthesis (1974)
IRVINE arthroplasty
TAR: What Went Wrong?
• High incidence of complications
» Delayed wound healing
» Fibular impingement
» Loosening (radiologic and clinical)
» Malleolar fractures
TAR: What Went Wrong?
Conaxial ankle replacement medial malleolar fracture
Ankle is in Varus and TibialComponent is Loose
What Went Wrong? Constrained
•Treated the ankle as a hinge joint - transfer stresses to bone-cement interface
»TPR »ICLH»Conaxial»Mayo Clinic (1976)
ICLH arthroplasty
What Went Wrong? Unconstrained
•Unstable, malleolar impingement»Mayo (1989)»Buckholz»Smith»Newton»Irvine
SMITH arthroplasty
TAR: History/Development
• Next Generation Ankle Replacements» Preserve bone stock
» Respect rotational axis
» Respect tibiopedal alignment
» Semiconstrained
» Biological fixation
Questions Outstanding
• Should the bearing be fixed or mobile?• Fixed Bearings
• Track record in knee and hip• One sided wear• More difficult exchange
• Mobile bearings• Good congruency Easier ligament tensioning• Incidence of medial joint pain secondary to tight
tensioning• Subluxation induced wear concerning
Questions Outstanding
• Approach• Anterior
• Coronal balance• Wound complications 10-34%
• Lateral• Fibular osteotomy• More difficult to balance ankle
Questions Outstanding
• What Surfaces Need Resurfacing?
»Superior tibiotalar joint (BP, Zimmer)»Superior and medial (TNK)»Superior and lateral (Salto)»Complete superior, partial medial/lateral (STAR, Hintegra, Inbone)»Superior, medial, lateral (Agility)
Superior & Lateral
Salto
Superior & Partial Medial/Lateral
STARHintegra
FDA approved TAA
Salto-Talaris with cement
S.T.A.R. without cement
INBONE with cement
Zimmer with cement
Prophecy without cement
Infinity without cement
Hintegra
Agility with cementEclipse with cement
Mobility
ExactechIntegra
Salto Total Ankle
• Next Generation……..
• Instrumentation to Find “Sweet Spot” in Fixed Bearing Prosthesis
Salto Data
• FB better than MB
• 98% survivorship @ 3.5 yrs
• 85% survivorship @ 7-11 yrs
• Significant improvement in gait
• Survivorship lower in low volume centers
Ankle Replacement: Salto
INBONE
Intra-Medullary Guidance(Need C-Arm)
Just anterior to posterior facet
Intra-MedullaryGuidanceIntra-
MedullaryGuidance
Intra-Medullary Guidance (C-Arm)
Stacking components
Works: Cutting guides
25 ° valgus
Problem: Soft tissue imbalance
Works: Soft tissue tensioning.
Ankle Replacement: Inbone
Inbone Results
• 3.9yr f/u survivorship 89%
• Clinical experiences and anecdotes
STAR
2nd Generation Designs
• S.T.A.R prosthesis (Waldemar Link, Germany)
» 3-component design» Free-gliding polyethylene meniscus» Rotation/gliding between tibia and meniscus» Flexion/extension between talar component
Ankle Replacement: STAR
STAR Outcomes
9/79 (11%) Painful Impingement Against Malleoli
STAR Outcomes
2/79 Subtalar Subsidence requiring Fusion
STAR Outcomes
STAR Results
• ? Concern on effect on talar blood supply
• Survivorship 96% @ 5 yrs
• Survivorship 90 - 70.7% @ 10yrs
• Survivorship 45.6% @ 14yrs
• Significant improvement in quality of life, pain, function
• Better function, = pain relief to fusion
Zimmer TAR
• Lateral approach
• Minimal bone resection
• Trabecular metal
• ? Difficulty with balancing
• Available only 1yr
Zimmer Results
• None to date
Selection of Implant
• Under 40yo• Mobile bearing – STAR, Salto, Hintegra• ? Zimmer
• Over 40yo• Mobile bearing• Fixed – Salto• ? Zimmer
• Over 300lb (136kg), revision, big deformity• Intramedullary device – InBone
Indications for TAA
•Optimal Patient • Less excessive demands» Rheumatoid arthritic
patients » Post-traumatic arthritis
• Older• Multiple joint arthrosis to slow them down
Indications for TAR
• Relative indication:» Youthful, active individuals
• Contraindications:» Talar AVN, Charcot Joint, neurologically
compromised foot, chronic infection
Outcomes
• TAR better than AA walking upstairs, downstairs, uphill
• TAR high rate of satisfaction & biomechanics of the gait similar to a healthy ankle
• Bilateral gait mechanics • Altered in fusion patients• Relatively recovered TAR patients
• Gait patterns in 3component, mobile-bearing TAR more closely resembled normal gait compared to fusion
Outcomes
• TAR & fusion significant improvements in various parameters of gait • Neither group functioned as well as normal control
subjects
• Fusion relieves pain and improves overall function• Persistent alterations in gait
• TAR - improvements in pain and gait up to 2 years
Conclusions
• Both ankle design and technique dictate what works to obtain a good result
• Expanding capability of ankle replacements• Offer opportunity to do ankle replacements
in all patients, regardless of deformity or previous surgery
RE ECT
the ankle
the foot
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