Lecture 39 parekh tar
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Transcript of Lecture 39 parekh tar
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