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