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