Hip prostheses as objects of history

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Hip prostheses as objects of history

• John Pickstone
• Francis Neary and Julie Anderson
• CHSTM, University of Manchester

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Summary
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A) Tracing a tradition

• Bone-setters rural and urban Lpool Mcr
• Radically conservative surgery
• Canal, war and efficiency
• Children, TB and accidents
• Post WWII medicine

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A short history of hip replacements

• Hemi-Arthroplasty and Inter-positional
  Arthroplasty esp. in USA and France, around WWII
• British sites for Total Hip Replacement post
  WWII Norwich (from 1940s) Stanmore (1956)
  Wrightington (1956)
  Redhill (1964) and Exeter (1969)

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Charnley Hip
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Short history 1

• post WWII research
• NHS and Uk inventions
• Charnley and hip centre
• Wrightington ex TB, regional funds
• Industrial resources engineer, plastics,
  germ-free systems etc

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Short history 2

• From the late 60s the Charnley (cemented UHMW
  Polyethylene cup and metal femoral stem) is
  British leader and is widely copied in Europe and
  the USA
• 1970s debates about best materials
  Charnley (Lancashire) stainless steel (SS)
  USA and S. UK mainly
  chrome-cobalt alloy (CC)
• 1970s debates re cementing, cement gun etc.

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Conversions and Terminations, esp. for UK?

• Stanmore Lateral tronchanteric osteotomy
  (Charnley approach) CC to CC but followed
  Charnley to plastic cup and CC stem
• Exeter entered after Charnley, similar
  materials, posterior approach
• Now in 2004, early indications from the new
  British National Joint Register suggest that
• Exeter hip outnumbers Charnley hips implanted by
  a ratio of 21.
• Third most popular implant is the C-Stem,
  developed at Wrightington Hospital by Depuy and
  similar to the Exeter Hip.

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Conclusions (i)Hip Surgery as an Innovation
System

• Stays open because
• a) Competition
• Surgeons- prosthesis named after them, own
  research programme, company benefits, autonomy
  and prestige
• Companies- stay ahead of market with new products
  unique to them (e.g. Zimmers market lead on
  double incision minimal invasive surgery but this
  is already being adapted by other companies)
• b) Convergences but also Differentiation, e.g.
  niches revisions

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Hip Surgery as an Innovation System

• c) Surgeons Conservatism results in low failure
  rates (declined, to c. 2)
• Major cause of failure is inexperienced surgeons
• Revision surgery is much more expensive in
  equipment and theatre and surgeon- time and is
  carried out at specialist centres
• Specialist surgeons tend to be conservative in
  using tried and tested prostheses with long
  follow up made by their allied companies

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Hip Surgery as an Innovation System

• d) Medical Uncertainties in R D and unresolved
  debates
• long term effects from material particles, or
  from mechanical effects of small surface
  difference (e.g. Exeter)- small changes can have
  marked effect on success
• Little use of animals (illegal for devices in the
  UK) some self-testing of materials
• Hard to predict the consequences of different
  designs, (e.g. Charnley on torque), lack of
  correspondence between in vitro and in vivo
  research
• Hence, overall slow feedback on success/
  failure
• Test time scale similar to changes in surgical
  populations, and time of introduction of new
  materials hence open system?

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C) Professional/craft-firms to multi-national
industry-led

• Individual surgeons promoting their prostheses
  through alliances with small companies (in
  orthopaedics or surgical instruments)
• from 1980s -- Specialist Companies bought by
  larger US companies (including pharmaceutical
  multinationals)
• Industrial labs and Universities commissioned by
  industry come to be main sites of R and D

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Multi national firms

• Mostly US based, but Smith and Nephew bought in
• Mostly from orthopaedic mfrs esp Zimmer so
  three are in Warsaw Indiana
• Complex relations with pharmaceuticals bought
  up, spun off
• From product champions, to securing young
  surgeons
• Industrial med research, exclusive deals,
  company reps etc

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Early Growth of Orthopaedic Companies United
States
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Acquisitions by USA Manufacturers of British
Companies

• Howmedica purchased London Splint Company 1969
• Zimmer purchased Delero Surgical 1980
• Depuy purcahsed Thackray 1990

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Acquisitions by Zimmer
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Acquisitions by DePuy (ALL)
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Acquisitions Relating to Hips Smith and Nephew
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Orthopaedic Manufacturers Association with
Pharmaceuticals

• ZIMMER Bristol Myers Squibb 1972-2000
• HOWMEDICA Pfizer 1972-1998
• RICHARDS Rorer 1968-1986
• DEPUY BoehringerMannheim 1974-1998
• Johnson and Johnson 1998

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Conclusions (ii)Nature of Competition

• a) Technology still in play all major suppliers
  supply full range of models (e.g. primary THRs)
• Depuy
• Stryker
• Zimmer
• Biomet

C-Stem Exeter MS-30 Genera-tion 4
Charnley Omnifit Allo Classic Stanmore
AML Securfit APR Balance
S-Rom Meridian Natural- Hip Bio-
Groove
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Nature of Competition

• b) Surgeons as testers and purchasers though
  they may have to conform to hospital purchasing
  patterns and company allegiances and exclusive
  supplier incentives
• c) Companies control R D and dissemination of
  research and look after their surgeons
• Support surgeons research and follow up with with
  personnel, equipment, conference infrastructure
  and funds to present papers
• Offer training and other incentives to use their
  prostheses and equipment
• Training under a consultant allies registrars
  with particular companies through social networks
• Non-technical features important in take up of
  particular prosthesis and method

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Nature of Competition

• d) Role of reps in theatre major source of
  assistance and education for surgeons
• E) Company support re recording, legal defence
  etc

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National differences

• UK NHS, less market competition, cost/ benefit
  analysis
• Conservative range of patients cement common
• Lack of regulatory body until MDA in 1990s
• Register from c 2005
• France persistence of ceramic heads (relates to
  specialist industries

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USA

• USA price tolerance, indeed inflation
• Worries re legal in cases of breakage
• FDA restricts use of certain innovations until
  thorough testing (e.g. cement)
• Medicare restrictions fr 80s, reduced cost of
  hospitalisation, not of prostheses
• Generally high cost variants, poorly documented,
  many worked less well than UK models.

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TRENDS

• Techniques
• Minimally Invasive Surgery
• Robotics
• Computer Assisted Surgery
• Resurfacing from Birmingham, UK, tow surgeons
  and a local metal company
• sold to S and N for 100m