01_Hamelynck_1

The history of Total Knee Replacement

THE HISTORY OF TOTAL KNEE REPLACEMENT

Karel J Hamelynck Amsterdam, NL

Interposition mold arthroplasty

1940 Campbell → MGM arthroplasty1941 Smith Petersen: a free-moving mold technique

>


Surface replacement of the tibia

Mc Keever →

Mc Intosh

Townley →


Hinge arthroplasty the mechanics of the knee simplified by resection ofarticulating surfaces and cruciate ligaments

1891: Gluck’s ivory totalknee hinge arthroplasty


Hinge arthroplasty in the 1940’s

Waldius Judet Shiers Young Guepar


Important innovations in arthroplasty

1960 methyl-methacrylate as a fixation material

1963 introduction of “high density” polyethylene plasticas a bearing surface

1971 the FDA approved of methyl-methacrylate forgeneral use in the US




Evolution of the condylar total knee in the 1970’s

knee resurfacing implants consisting of a single-piece femoral component covering both medial and lateral femoral condyles

a single-piece tibial component resurfacing both medial and lateral tibial plateaus

PMMA was used for fixation


Evolution of the condylar total knee in the 1970’s

the patello-femoral mechanism was not necessarilyincluded in the design: some designs had a femoral flange, patellar buttons were not used yet

two philosophies- the anatomic approach- the functional approach


The anatomic approach

just the articular surfaces were replaced or resurfaced

cruciate ligaments and most of the soft tissue constraints were preserved

implant surfaces were designed in such a manner, that a conflict with soft tissue constraints was avoided


The anatomic approachPolycentric knee (Gunston 1970)



Kodama-Yamamoto knee (1970) anatomical femoral component with femoral

flange minimally constrained single-piece PE tibial

component with a central cutout for preservation of both cruciate ligaments



UCI knee (Waugh and Smith, 1971) duplication of femoral condyles and tibial

plateaus using casting techniques unrestricted rotational freedom



The Anatomical knee (Townley, 1971) anatomically shaped asymmetrical femoral

condyles with asymmetrical patellar flange tibial plateaus with intact menisci surfaces largely nonconforming the first prosthesis with a patellar button!



The Leeds knee (Seedhom, 1972) anterior femoral flange with congruous

patellar articulation throughout flexion no need for patellar resurfacing single-piece polyethylene tibial component

with two oval concaved discs surface geometry allowing substantial

anteroposterior and rotational laxity in flexion


The history of total knee replacement


All anatomically designed knees had in common

the complex geometries were difficult to manufacture the surgery was considered too difficult for most surgeons most surgeons considered cruciate ligament resection

necessary to correct deformity


The functional approach

the mechanics of the knee simplified by resection of the condyles and the cruciate ligaments

no attempts to be anatomical

The history of total knee replacementThe history of Total Knee Replacement


The functional approach

The Freeman-Swanson prosthesis(1971)

both cruciate ligaments were resected a “roller-in-trough” design contact areas considerably enlarged the implant seated on flat cancelous bone

surfaces: no attempt was done to be anatomical!


The Freeman-Swanson prosthesis

Frequent changes of the patellofemoral joint


Freeman

instruments important for proper alignment flat right-angle bone cuts using intramedullary guides for

both femoral and tibial cuts spacers to check gaps remaining after making bone cuts tensor device for ligament balancing


The Hospital for Special SurgeryThe Hospital for Special Surgery

Duocondylar knee (1971)

Walker, Ranawat, Insall and Inglis preservation of cruciate ligaments linked femoral component separate tibial components no provision for patellar replacement


Conclusions of the Hospital for Special Surgery

arthroplasty of the patellofemoral joint should be included

preservation of both cruciate ligaments interferes with the correction of deformity

cement is insufficiently contained beneath two separate tibial components: therefore fixation is insecure.


The Hospital for Special Surgery

Duocondylar knee > Duopatella knee (Ranawat, 1974)

ACL sacrifice posterior cutout for preservation of PCL designed to solve the patellar problems

of the Duocondylar knee



Duocondylar knee > Total Condylar knee (Insall, 1974)

both cruciate ligament sacrifice a troughed anterior flange and a patellar

button were included the radii of the femoral and tibial

components were partially conforming, to provide stability with laxity


PCL retention versus PCL sacrifice

HSS, New York since 1976 cruciate ligament sacrifice Brigham, Boston posterior cruciate ligament retention

The real problem however was how to provide anteroposterior stability and condylar rollback



Insall Burstein Posterior Stabilized Knee (1980)

spine & cam patella buttons conforming geometry alignment checks built into more

precise instrumentation


The PCA experience (since 1984)

Universal instruments 6 basic bone cuts flat distal condyles heat pressed UHMWPE cementless fixation porous coating on all components


The PCA experience (since 1984)

Polyethylene wear better recognized as an importantfailure mechanism of total knee prostheses, due to- high contact stress on- small contact areas


The two most important problems of TKA

mechanical loosening and wear



The dilemma of design

Incongruent surfaces> unrestricted movements

> low constraint forces> minimal loosening

> high contact stresses> maximal poly wear

> maximal osteolysis



The dilemma of design

Congruent surfaces> low contact stresses

> minimal poly wear> minimal osteolysis

> restricted movements> high constraint forces

> maximal loosening


The Geomedic/Geometric knee (Averill, 1971)


Surprisingly

in the 1970’s and 1980’spolyethylene wear was notrecognized as a major cause of aseptic loosening of total knee components in a greatpart of the orthopaedic world


The solution

compromise: creating more conformity between components still allowing varus-valgus rotations and some axial rotation.

For many total knee systems thissituation still exists today!



O’Connor and Goodfellow

first described the principle of mobilebearings with congruent contact at thefemoro-tibial interface,the Oxford Knee (1976)



Buechel and Pappas

developed a mobile bearing total kneesystem, the New Jersey Integrated Knee system, later called the LCS (Low Contact Stress) knee prosthesisin Newark, New Jersey, USA in 1977



Mobile bearings in TKA

Large congruent surfaces> low contact stresses


Mobile bearings> unrestricted rotational movements



The future of total knee arthroplasty

What happened in the 1980’s?- 1980- - DePuy introduces the LCS mobile bearing knee- - Howmedica introduces the PCA total knee system- 1993- - Biomet introduces the AGC total knee system- 1984- - Johnson & Johnson the PFC Sigma knee- - Zimmer introduces the Miller-Galante knee



What happened in the 1980’s?

- 1987- - the Natural knee is introduced by Intermedics- 1989- - the Insall-Burstein II posterior stabilized knee- - Howmedica introduces the Kinemax knee




- 1990- - Howmedica introduces the Duracon- 1992- - Howmedica introduces the Interax total knee system- 1993- - S&N introduces the Profix knee system (Whiteside)-




- 1995- - Zimmer introduces the NexGen knee- - Wright Medical introduces the Advance knee system- 1996- - Osteonics introduces the Scorpio total knee system- 1997- - the medial-pivot knee (Wright Medical)



What really happened in the 1990’s?

- not very much- small changes of existing prostheses- after changing the design it got a new name !- follow up studies were difficult to achieve



What were the issues?

- fixation with or without cement- polyethylene wear - fixed or mobile bearings- the importance of good alignment- patella replacement yes or no- instability of the replaced knee



Fixation with or without cement

- intrinsic constraint :- the rotational forces are

conducted tothe bone-prosthesis interface

> loosening more likely to occur




Lesson of the past freedom of anatomical movement between prosthetic components is necessary to prevent mechanical loosening




Lesson of the past freedom of anatomical movement between prosthetic components is necessary to prevent mechanical loosening

Freedom of anatomical motion how?



Freedom of motion with fixed bearing knees

- Incongruent contact areas > high contact stresses >- maximal Poly wear > maximal osteolysis / loosening



Freedom of motion with fixed bearing knees

Incongruent contact areas > multi-directional - movements > maximal Poly wear and osteolysis



Intra-articular movements and Poly wear


UHMWPE orientates in principle direction of sliding (Pooley & Tabor 1972, Proc.Roy.Soc.Lon.A, 329, 251)

Strength increased parallel to sliding but reduced strength transverse to sliding(Wang et al. 1996, Proc.IMechE, 210H, 141)




Multidirectional motion accelerates UHMWPE wear(Wang et al. 1996, Proc.IMechE, 210H, 141)

Monodirectional motion reduces UHMWPE wear (Marrs et al. 1999, J.Mats.Sci.Mats.Med. 10, 333)




Multi-directional motion of the femoral component relative to the tibial bearing surface in fixed bearing TKR

Doubling the amount of internal-external rotation and anterior-posterior displacement produced a five-fold increase in wear rate


Freedom of motion with mobile bearing knees

- multi-directional movements - are decoupled and changed- into unilateral movements - wear is largely diminished



Mobile bearings in TKA

Large congruent surfaces> low contact stresses


Mobile bearings> unrestricted rotational movements




Mobile bearings

- have shown excellent results in longterm clinical follow- up and retrieval studies

- minimal mechanical loosening- minimal wear

However 80-85% of orthopedic surgeons is still using

fixed bearing knee replacement systems today !!!


The future of total knee replacement

Good mechanical alignment

What are we doing?

- is this the mechanical axis ?




What are we doing ?

- our bone cuts are not anatomical !!- where is the mechanical axis ?




Do we need computer assisted surgery (CAS)to malalign our knees moreprecisely?



Replacing the patella yes or no?

- to ensure good patellar tracking is more important thanpatellar replacement




- para-patellar release




- contouring the patella
















- geometry of the femoral component plays an importantrole


Femoral Design in TKA


The problem of instability



“Why are total knee arthroplasties failing today?”Peter F. Sharkey, MD; William J. Hozack, MD; Richard H. Rothman, MD,

PhD; Shani Shastri, MD; Sidney M. Jacoby, BA. CORR Nov 2002:7-14



“Current etiologies and modes of failure in revision TKA”Kevin J. Mulhall, Hassan M. Ghomrawi, Sean Scully, John J. Callighan,

Khaled J. SalehClinical Orthopaedics and Related Research 446, pg 45-50, 2006



Lessons learned from revision surgery

polyethylene wear is the most important reason of failure in long term follow up

insufficient surgery is the most important reason for failure in short term follow up

instability has become an important reason for revision



Instability why?

During TKA - removal of the articular surfaces - cruciate ligament resection.

And we expect that knee to be stable?

The future of total knee arthroplastyThe history of Total Knee Replacement


Stability of the knee is a DYNAMIC processguided by proprioception



It is even worse:

after cruciate ligament resection> release of a collateral ligament

to correct deformity

we are disregarding the negativeconsequences of collateral ligament release to achieve aperfect (?) alignment


The consequences of collateral ligament release

the mechanical stability provided by the ligaments isdiminished

the proprioceptiv function of the ligaments is destroyed> dynamic stability of the knee disturbed


The stability of the knee is a dynamic process

muscle force guided by the central and peripheral nerve system guided by proprioception


The principle of today’s TKA

It is mandatory to maintain the collateral frame of condyles and collateral ligaments to keep the knee stable



If some residual deformity is still present

not releasing the collateral ligaments should probablyprevail over release in order to support the stability ofthe knee

instability is created by the surgeon !!!



Do I need to talk about?

- gender specificity- minimally invasive surgery- high flexion knees



Total knee replacement today

- is a very successful procedure

- however we are still making too many mistakes- too many patients are not happy with their new knee- why so-called perfect knee replacements are painful?



Total knee replacement today

- we need to become better surgeons

- we need to get a more physiological TKA- avoid collateral ligament release- cruciate ligament retention in selected cases- use mobile bearings



Different prostheses in different pathologies and different patients, just replacingwhat is necessary and preserving what is needed



Thank you


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