TOTAL KNEE ARTHROPLASTY

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TOTAL KNEE ARTHROPLASTY

• Richard R. Pelker M.D., Ph.D.Professor Chief,
  Section of Joint Reconstruction
• Department of Orthopaedics Rehabilitation
• Yale University School of Medicine

Workers Compensation Conference on
ArthroplastyNovember 14, 2008
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KNEE ARTHROPLASTY

• Demographics
• Indications
• Alternatives
• Arthritis Risk Factors
• Surgical Technique
• Post Operative Protocol
• Results Complications
• Impairment Rating
• Activity after TKR

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TOTAL KNEE ARTHROPLASTY

• 500,000 per year in the U.S.
• 95 - 98 Success Rate
• 15 year (? Longer) Longevity
• ? of Revisions
• (? Unrealistic) Expectations

THE KNEES ARE THE FIRST THING TO GO!
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TKR UTILIZATION
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TKR UTILIZATION
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INDICATIONS

• PAIN
• 2nd Knee Arthritis
• FUNCTION
• Also
• Post Traumatic
• Deformity

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ALTERNATIVES

• Non Operative Rx
• NSAIDS - Motrin, Advil, Aleve
• Ambulatory Aids (cane, etc.)
• Rehab
• Orthotics Braces
• Injections
• Corticosteroids
• Hyaluronates (Synvisc, etc.)

• Operative Rx
• Arthroscopic Debridement
• Osteotomy
• Partial Replacement
• Biologic
• Cartilage Replacements
• Allografts

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? Factors that Increase the Risk for OA

• SYSTEMIC
• Heredity
• Age
• Gender
• INTRINSIC
• Injury
• Malalignment
• USE
• Weight
• Trauma
• Repetitive Stress
• High Impact Sports

Felson Clin Orthop, Volume 427()
Supplement.October 2004.S16-S21
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Heredity

• OA Not Hereditary
• Some Hereditary Disease associated with OA
• Genetic Predisposition
• Anatomy
• Cartilage
• Etc.
• Hereditability
• 50 of Occurrence in Hip and Hand - Hereditable
• 0 - 30 of Knee

Felson, Arthritis Rheum 4113431355, 1998
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AGE GENDER

• Men gt 50 Women gt 40
• BUT !!!
• 5 of population 35 - 54 years old have
  radiographic sx of OA

Roos Curr Opin Rheumatol, Volume 17(2).March
2005.195-200
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Weight

• BMI gt 27 ? OA KneeAnnals of the Rheumatic
  Diseases 200766158-162
• BMI gt 30 5 x Radiographic Knee OA

BMI Wt(kg) / Ht2 (m)
BMI Wt(lbs) 703 / Ht2 (in)
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Weight

• BMI gt 27 ? OA KneeAnnals of the Rheumatic
  Diseases 200766158-162
• BMI gt 30 5 x Radiographic Knee OA
• By age 85 (US) 1/2 All
• 2/3 Obese

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TRAUMA

• FRACTURE
• Intra-articular
• Extra-articular - malalignment
• MENISECTOMY
• LIGAMENTOUS INJURY / ACL

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TRAUMA

• FRACTURE
• MENISECTOMY
• Sx Radiographic OA 27 Mensiectomy vs 10
  Control (15 - 22 yrs post surgery) Arthritis
  Rheumatism. 50(9)2811-9, 2004 Sep.
• 43 xray sx of OA 16 yrs after limited
  Menisectomy (intact ACL)Arthritis Rheumatism.
  482178-87, 2003.
• LIGAMENTOUS INJURY / ACL

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TRAUMA

• FRACTURE
• MENISECTOMY
• LIGAMENTOUS INJURY / ACL
• Little evidence that ACL repair lessens incidence
  of OA
• Especially with concomitant meniscus injury

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INJURY
Roos Curr Opin Rheumatol, Volume 17(2).March
2005.195-200
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OA ACTIVITY? INJURY vs USE

• SPORTS
• RUNNING
• OCCUPATIONAL
• INCREASED LOADING
• REPETITION

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Running OA

• Table 1. Studies on Knee Osteoarthritis in
  Runners vs. Non Runner Controls
• From Felson Clin Orthop, Volume 427()
  Supplement.October 2004.S16-S21

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OCCUPATION

• Increased Prevalence in Jobs
• Repetitive Bending Strenuous Activity
• Heavy Lifting
• Squatting
• Knee Bending
• Kneeling
• ? Causal or Injury

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GOALS of TKR

• DECREASE PAIN
• RESTORE
• Anatomy
• Function
• RESTORE
• Mechanical Axis
• ROM
• Stability

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PREOPERATIVE ASSESMENT

• Hx PE
• Radiographs
• Medical Clearance

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ANATOMYBONES

• FEMUR
• TIBIA
• PATELLA

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ANATOMYLIGAMENTS

• ACL
• PCL
• MCL
• LCL

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ANATOMYMUSCLES

• EXTENSORS
• Quadriceps
• FLEXORS

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SURGERY

• Exposure
• Bone Cuts
• Alignment Measurement Jigs
• Soft Tissue Balance
• Insertion of Prosthesis
• Femur
• Tibia Trey
• Polyethylene Insert
• Patella

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Exposure

• Skin Incision
• Split Muscle
• Expose bone

SNR SURG TECH
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Prepare Femur

• Drill Guide Hole in Femur
• Insert Rod and Alignment Block

SNR SURG TECH
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Prepare Femur

• Measure Size of Femur
• Place Cutting Block on Femur

SNR SURG TECH
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Prepare Femur

• Make Femoral Bone Cuts

SNR SURG TECH
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Prepare Tibia

• Drill Guide Hole in Tibia
• Place Alignment Jig in Tibia
• Make Tibial Cuts

SNR SURG TECH
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Prepare Patella

• Measure Patella Size Thickness
• Place Cutting Guide on Patella
• Make Patella Cuts

SNR SURG TECH
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Insert Trials

• Insert Femoral, Tibial, Patella Insert Trial
• Asses Alignment, ROM, Ligament Balance

SNR SURG TECH
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Insert Components

• Clean Bone
• Cement in Components
• Reassess
• Soft Tissue Closure

SNR SURG TECH
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PROSTHETIC CHOICES

• MATERIALS
• Metals
• Cobalt Chrome
• Titanium
• Polyethylene
• Ceramics
• BEARING SURFACES
• Metal - Polyethylene
• Zirconium - Polyethylene

• DESIGN
• Constraint
• Crux Retaining
• Crux Replacing
• Constrained
• Hinged
• Mobile Bearing
• SURGERY
• Mini Incision
• Computer Navigation

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TIME

• SURGERY Hour
• HOSPITAL 1-3 Days
• REHABILITATION 1-6 Months

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Rehabilitation

• PT, HEP, CPM
• Motion
• Strength
• Balance

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Rehabilitation

• 24o
• Ambulation
• Motion - CPM
• 1 Week
• Stairs
• Independent
• 1 Month
• Drive

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Average Post Op Protocol AAHKS Survey

• Bending 4th week
• Driving 5th week
• Sitting _at_ office desk 6th week
• Carry brief case 7th week
• Climb ladder 9th week
• Work on hands knees 11th week

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RESULTS

• 95 - 98 good to excellent
• 80 -90 15 year survival

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COMPLICATIONS

• INFECTION
• DVT - PE (Blood Clots)
• PAIN
• LOOSENING / WEAR
• INSTABLITY
• NEUROLOGIC
• VASCULAR

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Impairment Evaluation

• Knee Score (100 points)
• Pain 50 points
• Motion 25 points
• Stability 25 points
• Deductions
• Function Score (100 points)
• Walking 50 points
• Stairs 50 points
• Deductions

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Knee Score

• Pain (50 points)
• None 50 points
• Mild or Occasional 45 points Stairs only 40
  points Walking Stairs 30 points
• Moderate Occasional 20 points Continual 10
  points
• Severe 0 points

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Knee Score

• Motion (25 points)
• 125 deg 25 point
• (5 deg 1 point)
• Stability (25 points)
• Medial - Lateral
• lt 5 deg 15 points
• 6 - 9 deg 10 points
• 10 - 14 deg 5 points
• gt 15 deg 0 points
• Anterior - Posterior
• lt 5 mm 10 points
• 5 - 9 mm 5 points
• gt 9 mm 0 points

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Deductions

• Extensor Lag (-15 points)
• Flexion Contracture (-20 points)
• Malalignment ( -20 points)

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Deductions

• Extensor Lag (-15 points)
• lt 10 deg -5 points
• 10 - 20 deg -10 points
• gt 20 deg -15 points

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Deductions

• Flexion Contracture (-20 points)
• 5 - 9 deg -2 points
• 10 - 15 deg -5 points
• 16 - 20 deg -10 points
• gt 20 deg -20 points

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Deductions

• Alignment (-20 points)
• 0 - 4 deg 0 points
• 5 - 10 deg -3 points per deg
• 11 - 15 deg -3 points per deg
• gt 15 deg -20 points

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Permanent Physical Impairment
Whole Person (Lower Ext)

• TKR
• GOOD (85 - 100 points) 15 (37)
• FAIR (50 - 84 points) 20 (50)
• POOR (lt 50 points) 30 (75)

AMA Guide to PPI - 5th ed
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Permanent Physical Impairment
Whole Person (Lower Ext)

• TKR
• GOOD (85 - 100 points) 15 (37)
• FAIR (50 - 84 points) 20 (50)
• POOR (lt 50 points) 30 (75)
• Menisectomy (Med or Lat)
• Total 3 (7)
• Cruciate Lig Laxity
• Severe 10 (25)
• Arthritis
• 0 mm cartilage remaining 20 (50)
• Amputation
• BKA 28 (70)
• AKA 32 (80)

AMA Guide to PPI - 5th ed
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LIFE AFTER TKR
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FUNCTION

• ABILITY To Perform A Function VS
• ADVISABILITY To Perform A Function VS
• PATINETS Expectations

CONSEQUENSES
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Physically Able

• Walk
• Kneel ???
• Bend
• Stairs
• Drive - 4 weeks post surgery

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Discouraged Activities KNEE SOCIETY

• In general, patients who have undergone total
  knee replacement should avoid high-impact
  activities that cause high stress loads on the
  implant and therefore may increase the risk of
  early failure.

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Questionable Activities

• Higher Impact Activities
• Running
• Jumping
• Heavy Lifting

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ACTIVITIES AFTER TKR

• Driving 86 after 5th week
• Climbing Ladder 85 after 9th week
• Crawling 67 after 11th week
• 33 never allow
• Weight Carried
• 10 lbs 98 after 9 weeks
• 50 lbs 50 after 14 weeks
• (Rarely allowed 89 after 10 weeks)

AAHKS Survey 1998
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ACTIVITIES AFTER TKR

• Recommended Activities Not recommended
  Activities ?????
• Low-impact aerobics Racquetball Fencing
• Stationary bicycling Squash Roller Blade
• Bowling Rock climbing Inline Skating
• Golf Soccer Downhill Skiing
• Dancing Single tennis Weight Lifting
• Horseback riding Volleyball
• Croquet Football
• Walking Gymnastics
• Swimming Lacrosse
• Shooting Hockey
• Shuffleboard Basketball
• Horseshoes Jogging
• Road bicycling ) Handball
• Canoeing )
• Hiking )
• Rowing )
• Cross-country skiing )

experienced patients ()
Healy et al. American Journal of Sports Medicine
200129 377 - 388
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Knee Society Survey1999 v 2005

• ALLOWED 1999 2005Bowling ? ?Stationary
  cycling ? ?Ballroom dancing ? ? Golf ? ?
  Horseback riding ? With Experience
  Shuffleboard ? ? Swimming ? ? Walking ? ?
  Canoeing With Experience ? Cycling With
  Experience ? Square dancing NA ? Hiking With
  Experience ? Speed walking With Experience ?

Healy et al., Athletic Activity After Total
Joint ArthroplastyJBJS 2008902245-2252
58
Knee Society Survey1999 v 2005

• Allowed with Experience 1999 2005Canoeing ? Allow
  ed Cycling ? Allowed Hiking ? Allowed
  Rowing ? ? Ice Skating ? ? Cross-country
  skiing ? ? Stationary skiing ? ? Doubles
  tennis ? ? Speed walking ? Allowed Weight
  Machine ? No Consensus Horseback riding ? ?
  Downhill skiing No Consensus ?

Healy et al., Athletic Activity After Total
Joint ArthroplastyJBJS 2008902245-2252
59
Knee Society Survey1999 v 2005

• Not Recommended 1999 2005Baseball ? No
  Consensus Basketball ? ?Football ? ?
  Gymnastics ? No Consensus Handball ? No
  Consensus Hockey ? No Consensus Jogging ? ?
  Rock climbing ? No Consensus Soccer ? ?
  Squash / racquetball ? No Consensus Singles
  tennis ? No Consensus Volleyball ? ?

Healy et al., Athletic Activity After Total
Joint ArthroplastyJBJS 2008902245-2252
60
Knee Society Survey1999 v 2005

• NO CONSENSUS 1999 2005Square dancing ? Allowed
  Fencing ? ?Roller skating ? ? Downhill
  skiing ? With ExpWeightlifting ? ?
  Baseball Not Rec ? Gymnastics Not Rec ?
  Handball Not Rec ? Hockey Not Rec ? Rock
  climbing Not Rec ? Squash / racquetball Not
  Rec ? Singles tennis Not Rec ? Weight
  machine NA ?

Healy et al., Athletic Activity After Total
Joint ArthroplastyJBJS 2008902245-2252
61
? TIME TO RTW

• ABSOLUTE
• In patient (hospital rehab)
• Age
• Health
• Previous Activity Level
• Rehab / PT
• Transportation
• Accommodations Work Requirements
• Sedentery vs. Manual Labor
• Ambulatory aids on the job
• Part Time

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What Does It Cost
63
What Does It Cost
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Is It Worth It?

• Society
• QALY
• 2.5 yrs
• 4.2 - 6.7 yrs
• American College of Rheumatology Boston, Mass
  2007
• Individual
• Priceless

If you put the federal government in charge of
the Sahara Desert, in five years there'd be a
shortage of sand. --Milton Freidman
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SUMMARY ?

• 95 - 98 Good to Excellent Results
• Pain Relief
• Function
• 15 () years Longevity
• Increasing Burden
• Aging population
• Revisions