New Technologies and Challenges Joint Replacement

1
New Technologies and ChallengesJoint
Replacement

• Prof Stephen Graves
• Director AOA National Joint Replacement Registry

2
Australian Orthopaedic
Association

• National Joint Replacement Registry
• (AOA NJRR)

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AOA NJRR

• Commenced in 1999
• State by State implementation
• Fully National in 2002
• Collaboration of Orthopaedic surgeons,
  Governments, Hospitals (Public and Private) and
  Industry
• Funded entirely By Commonwealth
• Quality information on Australian joint
  replacement surgery not available form any other
  source
• Determines the outcome in particular the risk of
  revision

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Changing Rate of Joint Replacement
All Joints 93.8 Hips 61.9 Knees 138.4
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Currently

• Approx 65,000 procedures p.a.
• In excess of 1 billion p.a.
• Prostheses 35 of cost and increasing
• Over 60 of procedures in private
• The rate of increase is greater in private
• By 2016 135,000 procedures p.a
• What in private?

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Outcomes

• Registry uses Revision is an indication of
  failure of a joint replacement procedure
• Proportion of Procedures undertaken that are
  revisions
• 2001 Hip 14.2 Knee 10
• 2005 Hip 12.1 Knee 8.2
• As good or better than most countries

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Comparison to Sweden

• Proportion of procedures that are revisions
• Australia Hip 12.1 Knee 8.2
• Sweden Hip 7-8 Knee 7
• Risk of Revision Surgery is better indicator of
  success
• Australia 20-25 (Estimated Hip and Knee)
• Sweden 10 (Hip and Knee)

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Expenditure Implications

• Reducing proportion of revisions by 1 decreases
  revision procedures by 650 p.a.
• ( 16 32 million)
• If Australia had the same rate of revision for
  hip and knee replacement as Sweden there would be
  3250 less revisions a year
• ( 81 and 162 million p.a.)
• Reduced by 2 p.a. since 2001

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Why the difference

• Detailed in Recent Report for the Australian
  Centre for Health Research (ACHR)
• Data from AOA NJRR 2006 Annual Report
• Identical demographics of patients receiving
  joint replacement surgery
• Some differences in patient selection
• Major differences in prostheses selection
• Major differences in prostheses fixation
• Greater uptake of new prostheses technology in
  Australia

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FNOF outcomes by Age
Monoblock
Modular
Bipolar
Data 1st September 1999 to 31st December 2005
     
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Outcomes related to Category of Prostheses for
Treatment of FNOF

• Modular and bipolar better than monoblock
• Differences are greatest in the younger age
  groups. (less than 75, and 75-84)
• Bipolar may be better than Modular except in over
  85 yr old age group
• Cement fixation much better no matter what type
  of prostheses

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Outcomes Conventional Primary Total Hip
Data 1st September 1999 to 31st December 2005
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Outcomes by Age Fixation
Under 55
55-64
65-74
Over 75
     
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Trends in Prosthesis Fixation Conventional
Primary THR
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Resurfacing Hip Replacement

• Increasing use
• (8.9 of primary THR 2005)
• Increasing use of prostheses other than the
  Birmingham
• (96.3 2001 and 63.5 2002)

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Outcomes Resurfacing V Conventional THR (OA
only)
Data 1st September 1999 to 31st December 2005
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Cumulative Percentage Revision by Gender
Data 1st September 1999 to 31st December 2005
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Cumulative Percentage Revision by Age
Data 1st September 1999 to 31st December 2005
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Approach to differences in categories of
prostheses and prostheses fixation

• Many examples in both hip and knee replacement
• Registry identified variation in general is
  responded to very quickly
• Complexity in understanding and determining
  implication of findings
• Best left for the profession to decide
• AOA to establish Guidelines based on Registry
  Data

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Registry is able to compare outcomes of
Individual prosthesis

• Least revised
• Most revised
• Those with a higher than anticipated rate of
  revision

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Cemented Primary THRs
Minimum 1000 Observed component years for least
revised Data 1st September 1999 to 31st December
2005
22
Least Revised Hybrid and Cementless Primary THRs
Minimum 1000 Observed component years Less than
2 Revision at 2 years Data 1st September 1999
to 31st December 2005
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Most Revised Cementless Components
Data 1st September 1999 to 31st December 2005
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Revision rates of different Resurfacing prostheses
Data 1st September 1999 to 31st December 2005
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Preservation Fixed
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Genesis II Cementless Oxinium
 
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Outcomes of New Prostheses
Prosthesis type Number of prostheses with CRR 3 years or less Compared to top 3 with CRR of 4 or more years and over 1000 procedures Compared to top 3 with CRR of 4 or more years and over 1000 procedures Compared to top 3 with CRR of 4 or more years and over 1000 procedures
Prosthesis type Number of prostheses with CRR 3 years or less Better Same Worse
Uni Knee 14 0 2 12
Cemented TKR 4 0 0 4
Cementless TKR 12 0 6 6
Cemented THR 2 0 0 2
Cementless THR 71 0 63 8
Total 103 0 71 32
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New Prostheses

• None have performed better than previously
  approved and well established prostheses
• Many have higher revision rates
• Some have been considerably worse
• All are associated with increased expenditure

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New Prostheses Considerations

• Currently Class IIb
• Europe recently changed to Class III
• What clinical information should be required
  prior to approval ?
• Clinical Trials
• RSA studies
• Do parameters need to be set ?
• Is equivalence sufficient for approval ?
• How are minor modifications to be handled ?
• Innovation and development must be encouraged

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Enhancing outcomes

• Focus on what is best for patient outcomes
• Guidelines for joint surgery using Registry
  information (appropriate patient and appropriate
  procedure)?
• Reduce prostheses choice? How?
• Remove poor performing prostheses from list?
• Reduce or cease funding for poor performing
  prostheses?
• Regulate differently the introduction of new
  prostheses?
• Is this experience relevant to other devices?