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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
