Contemporary Solutions for Arthritis of the Knee

Contemporary Solutions for Arthritis of the Knee

Arthritis affects over 70 million AmericansArthritis affects over 70 million Americans

•2nd only to heart disease in causing disability

•1 million new patients diagnosed each year

• Affects 50% of people 65yrs or older

•2nd only to heart disease in causing disability

•1 million new patients diagnosed each year

• Affects 50% of people 65yrs or older

Osteoarthritis is most common form of ArthritisOsteoarthritis is most common form of Arthritis

Rheumatoid arthritis Post-traumatic arthritis Inflammatory arthritis Septic arthritis

All result in loss of joint cartilage

Rheumatoid arthritis Post-traumatic arthritis Inflammatory arthritis Septic arthritis

All result in loss of joint cartilage

Healthy

Diseased

Factors that influence the onset of arthritisFactors that influence the onset of arthritis

Heredity / Family history Age Weight Gender Trauma / Repetitive

stress High impact sports Other illnesses

Heredity / Family history Age Weight Gender Trauma / Repetitive

stress High impact sports Other illnesses

Diseased compartmentDiseased compartment

The Knee is the #1 Joint Affected by ArthritisThe Knee is the #1 Joint Affected by Arthritis

Large weight bearing joint Complex motion pattern Common site of injury

Ligaments, meniscus

Large weight bearing joint Complex motion pattern Common site of injury

Ligaments, meniscus

Presenting symptoms of Knee ArthritisPresenting symptoms of Knee Arthritis

Stiffness

Swelling

Deformity (“knocked-knee”/ “bow-legged”)

Crepitus (clicking, crunching, grinding)

PAIN Start-up

Activity limiting

Nighttime

Stiffness

Swelling

Deformity (“knocked-knee”/ “bow-legged”)

Crepitus (clicking, crunching, grinding)

PAIN Start-up

Activity limiting

Nighttime

Diagnostic StudiesDiagnostic Studies Weight-bearing Radiographs

A/P, Lateral, Notch view Fairbanks Changes (subtle)

• Joint space narrowing

• Squaring of the condyles

• Osteophytes

• Sclerosis

MRI Most helpful for ligaments and

meniscal injury Mechanical symptoms “Symptoms don’t seem to fit”

Weight-bearing Radiographs A/P, Lateral, Notch view Fairbanks Changes (subtle)

• Joint space narrowing

• Squaring of the condyles

• Osteophytes

• Sclerosis

MRI Most helpful for ligaments and

meniscal injury Mechanical symptoms “Symptoms don’t seem to fit”

Initial Conservative TreatmentsInitial Conservative Treatments

Tylenol®

NSAID’s

(non-steroidal anti-inflammatory drugs)

Tylenol®

NSAID’s

(non-steroidal anti-inflammatory drugs)

Physical Therapy

Activity Modification

Weight Loss

Nutritional Supplements

Physical Therapy

Activity Modification

Weight Loss

Nutritional Supplements

The first level of invasiveness:Therapeutic InjectionsThe first level of invasiveness:Therapeutic Injections Corticosteroid

Inter-articular anti-inflammatory agent

Short term symptomatic relief

Viscoelastic Series Hyaluronic Acid injections: 3-5

shots

Attempts to augment normal joint lubrication properties

Potential for more long lasting relief (6mos-1yr)

Corticosteroid Inter-articular anti-inflammatory

agent

Short term symptomatic relief

Viscoelastic Series Hyaluronic Acid injections: 3-5

shots

Attempts to augment normal joint lubrication properties

Potential for more long lasting relief (6mos-1yr)

The Orthopaedic SpecialistThe Orthopaedic Specialist

When conservative treatments no longer resolve activity limiting pain caused by osteoarthritis then . . .

Surgical and reconstructive treatments may be appropriate

When conservative treatments no longer resolve activity limiting pain caused by osteoarthritis then . . .

Surgical and reconstructive treatments may be appropriate

Surgical Options for Knee ArthritisSurgical Options for Knee Arthritis Arthroscopy

Debridement

Meniscectomy

Chondroplasty

Osteotomy Bone cut and re-aligned onto remaining good cartilage

Arthroplasty (Joint Replacement) Uni-compartmental knee replacement (partial knee replacement)

Tri-compartmental knee replacement (total knee replacement)

Arthroscopy Debridement

Meniscectomy

Chondroplasty

Osteotomy Bone cut and re-aligned onto remaining good cartilage

Arthroplasty (Joint Replacement) Uni-compartmental knee replacement (partial knee replacement)

Tri-compartmental knee replacement (total knee replacement)

Arthroscopic Debridement“clean out” or “scrape bone”Arthroscopic Debridement“clean out” or “scrape bone”

Somewhat unpredictable results

50 to 66 percent get relief for some period of time

Best for patients with mechanical symptoms (catching, locking and giving out)

Somewhat unpredictable results

50 to 66 percent get relief for some period of time

Best for patients with mechanical symptoms (catching, locking and giving out)

Knee OsteotomyRe-align weight-bearing axis through “good” cartilageKnee OsteotomyRe-align weight-bearing axis through “good” cartilage

Most popular before success of contemporary knee replacement

Useful for patients too young, heavy or active for knee implants

Early results acceptable, questionable durability

Most popular before success of contemporary knee replacement

Useful for patients too young, heavy or active for knee implants

Early results acceptable, questionable durability

End-Stage Osteoarthritis Knee ReplacementEnd-Stage Osteoarthritis Knee Replacement

Uni-compartmental Knee Replacement “Uni,” “partial replacement” or

UKR

Tri-compartmental Knee Replacement “total replacement” or TKR

Uni-compartmental Knee Replacement “Uni,” “partial replacement” or

UKR

Tri-compartmental Knee Replacement “total replacement” or TKR

Minimally Invasive Knee ReplacementMinimally Invasive Knee Replacement

Same implants as traditional knee replacements

Components

Femoral

Tibial

Patellar

Same implants as traditional knee replacements

Components

Femoral

Tibial

Patellar

Minimally Invasive Knee ReplacementMinimally Invasive Knee Replacement

Potential Benefits: Less trauma to the knee Less bleeding Less pain Cosmetically appealing (smaller scar) Shorter hospital stay Quicker recovery than traditional total knee replacement

Potential Complications and Risks Factors that effect risks:

Skill of the surgeon Age, weight and health of the patient Patient compliance

Potential Benefits: Less trauma to the knee Less bleeding Less pain Cosmetically appealing (smaller scar) Shorter hospital stay Quicker recovery than traditional total knee replacement

Potential Complications and Risks Factors that effect risks:

Skill of the surgeon Age, weight and health of the patient Patient compliance

Total Knee ReplacementTotal Knee Replacement

Most common joint replaced

First performed in 1968

Nearly 400,000 TKR’s performed per year in US

Most common joint replaced

First performed in 1968

Nearly 400,000 TKR’s performed per year in US

Total Knee ReplacementTotal Knee Replacement

Patient satisfaction typically 85-90% Relieves pain

Restores mobility

Durability well documented at ~90% survivorship @10yrs

Improvements in materials and techniques continue to increase effectiveness

Patient satisfaction typically 85-90% Relieves pain

Restores mobility

Durability well documented at ~90% survivorship @10yrs

Improvements in materials and techniques continue to increase effectiveness

TKR: Who’s a candidate?TKR: Who’s a candidate? Many patients that could be helped by knee

replacement don’t know about it or do not seek care Lack of knowledge

Misconceptions

Fear

Many patients that could be helped by knee replacement don’t know about it or do not seek care Lack of knowledge

Misconceptions

Fear28%

11%

16%

26%

19%

Less than 1 year

1-2 years

2-3 years

3-5 years

More than 5 years

How long do patients wait before they see their surgeon?How long do patients wait before they see their surgeon?

Important Patient Demographic TrendsImportant Patient Demographic Trends

Over 65yr group is the most rapidly expanding segment of our population

Increasing individual longevity will result in a greater number of individuals living long enough to be diagnosed with arthritis

Over 65yr group is the most rapidly expanding segment of our population

Increasing individual longevity will result in a greater number of individuals living long enough to be diagnosed with arthritis

(Average age of today’s total knee replacement patient is 67yrs)(Average age of today’s total knee replacement patient is 67yrs)

Important Patient Demographic Trends Important Patient Demographic Trends

36% of TKR patients are between ages 40-64

This group of younger patients requiring TKR is increasing Those individuals requiring treatment for their arthritis

will need solutions with even greater durability

36% of TKR patients are between ages 40-64

This group of younger patients requiring TKR is increasing Those individuals requiring treatment for their arthritis

will need solutions with even greater durability

Common Misconceptions Delaying TKR SurgeryCommon Misconceptions Delaying TKR Surgery

Too Young—Components will “wear out” and have to be revised

Too Active—Components will “wear out” prematurely and have to be revised

Too Heavy—Stresses on components will cause them to “wear out” or “break”

Too Young—Components will “wear out” and have to be revised

Too Active—Components will “wear out” prematurely and have to be revised

Too Heavy—Stresses on components will cause them to “wear out” or “break”

Kinematics of a traditional (fixed-bearing) TKRKinematics of a traditional (fixed-bearing) TKR

Normal knee motion is a complex combination Flexion/extension

Anterior/posterior translation

Internal/external rotation

Varus/valgus lift off

Normal knee motion is a complex combination Flexion/extension

Anterior/posterior translation

Internal/external rotation

Varus/valgus lift off

Leading Causes of TKR FailuresLeading Causes of TKR Failures

Component loosens

Surgical technique

Infections

Polyethylene component wears out What causes this wear?

What can we do about it?

Component loosens

Surgical technique

Infections

Polyethylene component wears out What causes this wear?

What can we do about it?

Addressing Polyethylene WearAddressing Polyethylene Wear

Wear is affected by

Implant design

Implant materials

Implant alignment (surgical technique)

Wear is affected by

Implant design

Implant materials

Implant alignment (surgical technique)

Polyethylene WearPolyethylene Wear

One of the leading causes of implant failure over time

Osteolysis Early Revision Negative Effect/Perception of patient Decreased Range of Indications Implant design and materials chosen

are two of the most significant things that can be done to minimize (or virtually eliminate) the effect

One of the leading causes of implant failure over time

Osteolysis Early Revision Negative Effect/Perception of patient Decreased Range of Indications Implant design and materials chosen

are two of the most significant things that can be done to minimize (or virtually eliminate) the effect

Implant Design & MaterialsImplant Design & Materials

Stress = Load/AreaStress = Load/Area

Area StressArea Stress

Implant Design & Materials – continuedImplant Design & Materials – continued

Overall applied stress (force)

Surface contact area Limitation in contact

area results in relatively high level of Polyethylene stress (wear)

Sheer

Overall applied stress (force)

Surface contact area Limitation in contact

area results in relatively high level of Polyethylene stress (wear)

Sheer

Fixed Bearing SystemFixed Bearing System

Rotating Platform SystemRotating Platform System

Contact Stress PatchesContact Stress Patches

If Contact Stress is not OptimizedIf Contact Stress is not Optimized

Results in relatively high level of Polyethylene stress (wear) Results in relatively high level of Polyethylene stress (wear)

If alignment is not optimized…If alignment is not optimized…

Predisposes to accelerated polyethylene wearPredisposes to accelerated polyethylene wear

10°

Today’s ImplantsToday’s Implants

The Goal of a TKR Implant Restore normal function of the knee Last as long as possible

Solutions Fixed Bearing TKR System A Mobile Bearing/ Rotating Platform TKR System

The Goal of a TKR Implant Restore normal function of the knee Last as long as possible

Solutions Fixed Bearing TKR System A Mobile Bearing/ Rotating Platform TKR System

Fixed Bearing TKR SystemsFixed Bearing TKR Systems

Good clinical results

Designs of Fixed Bearing systems may not optimize wear reduction

Does not mimic all range of motion of the natural knee

Good clinical results

Designs of Fixed Bearing systems may not optimize wear reduction

Does not mimic all range of motion of the natural knee

The Rotating Platform Solution “Congruity with Mobility” The Rotating Platform Solution “Congruity with Mobility”

Constraint forces minimized by allowing bearing rotation Articulates like the natural knee Full and normal range of motion Increased contact area results in reduced

polyethylene stresses (wear)

• 94% reduction over Fixed Bearing Systems* Shear forces at implant-bone interface

minimized Could minimize loosening

Outstanding clinical results for over 25 years

Constraint forces minimized by allowing bearing rotation Articulates like the natural knee Full and normal range of motion Increased contact area results in reduced

polyethylene stresses (wear)

• 94% reduction over Fixed Bearing Systems* Shear forces at implant-bone interface

minimized Could minimize loosening

Outstanding clinical results for over 25 years

Advantages of a Rotating Platform Knee Replacement“Show me the Data”

Advantages of a Rotating Platform Knee Replacement“Show me the Data”

McNulty, ASTM,2002McNulty, ASTM,2002

94% wear reduction with

Rotating Platform vs

Fixed bearing

94% wear reduction with

Rotating Platform vs

Fixed bearing

0

10

20

30

40

50

60

70

80

0.0 1.0 2.0 3.0 4.0 5.0 6.0

Cycles (Million)

Gra

vim

etri

c W

ear

(Mg)

Fixed Bearing GVF Mobile Bearing GVF

0

5

10

15

Fixed Bearing Rotating Platform

Gra

vim

etri

c W

ear

(Mg/

M)

94% Wear Reduction

0

5

10

15

Fixed Bearing Rotating Platform

Gra

vim

etri

c W

ear

(Mg/

M)

94% Wear Reduction

Fig. 1 Average Wear Rate per Million Cycles

Self Aligning Q-Angle Less Stress on Quadriceps

Reduced Lateral Release rate

• Reduced Bleeding

• Reduced Pain

• Improved Recovery

Maximize Tibial Placement and Alignment

Extensor Mechanism Aligns w/ the Trochlear Groove

Promotes Patellar Tracking

Self Aligning Q-Angle Less Stress on Quadriceps

Reduced Lateral Release rate

• Reduced Bleeding

• Reduced Pain

• Improved Recovery

Maximize Tibial Placement and Alignment

Extensor Mechanism Aligns w/ the Trochlear Groove

Promotes Patellar Tracking

Implant AlignmentImplant Alignment

Advantages of a Rotating Platform Knee Replacement“Show me the Data”

Advantages of a Rotating Platform Knee Replacement“Show me the Data”

Twenty year evaluation of rotating platform mobile bearing knee replacements Survivorship 97.7% at 16-20yr

Buechel et al Clin Ortho 2001

Cemented rotating-platform total knee replacements 9-12yr follow-up 119 TKA’s, Survivorship 100% at 10yrs

Callahan et al JBJS 2000

Twenty year evaluation of rotating platform mobile bearing knee replacements Survivorship 97.7% at 16-20yr

Buechel et al Clin Ortho 2001

Cemented rotating-platform total knee replacements 9-12yr follow-up 119 TKA’s, Survivorship 100% at 10yrs

Callahan et al JBJS 2000

Contemporary Solutions for Arthritis of the Knee Summary

Contemporary Solutions for Arthritis of the Knee Summary

The number of patients suffering from arthritis of the knee is steadily growing

Of the patients suffering from knee arthritis nearly half may not seek treatment due to poor information or fear

Patients seeking care are younger, more active and more demanding

Total knee replacement is a reproducible, reliable and durable solution to end-stage knee arthritis

The number of patients suffering from arthritis of the knee is steadily growing

Of the patients suffering from knee arthritis nearly half may not seek treatment due to poor information or fear

Patients seeking care are younger, more active and more demanding

Total knee replacement is a reproducible, reliable and durable solution to end-stage knee arthritis

Thank YouSponsored by

www.kneereplacement.com

Thank YouSponsored by

www.kneereplacement.com