Which Primary Total Hip Replacement - Kate Owers 15/1/2004
Which primary THR?
Murray, Carr and Bulstrode JBJS Br July 1995 77B p520-27
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essentially compared all the available THR implants in
- 62 implants , 19 companies, 50% introduced in last 5 yrs
- 10-fold price difference
- only 30% had any results in peer reviewed journals- only 8 had 5 yr survival data
- some designs have good 5 year, but poor 10 year data
- once get to good 10 yr data, will probably behave like Charnley
- 5000 revision THRs per year – cost++ and worse outcome
- v. few randomised trials comparing implants – none for cemented vs. uncemented
Only 3 implants had >10 yr data
- Muller 10 year data
o straight stem better than curved
- Stanmore 15 year data (now 22 yr data)
o small straight or curved stem, 25mm head, UHMWPE cup
- Charnley 20 year data – 85-90% survival (now 25 yr data)
o gold standard against which all other designs should be compared
o cheap
o originally monoblock – stainless steel, 22.25mm head and UHMWPE cup
but modifications in design and cementing techniques since 1960s
- cannot compare studies if different outcome scores used – not just ‘revision’ or radiological loosening
- paper suggests various end-points more realistic eg. level of pain, not just revision
- Swedish study looks at ‘revision’, many surgeons and techniques
- results NOT just down to implant design and behaviour in lab
Cemented THRs
The outcome of Charnley THR with cement after minimum 20 year follow-up
Schulte, Callaghan, Kelley and Johnston JBJS 75A 1993 961-75
- 330 THRs, 262 patients 1970-72
- one surgeon
- > 20 yrs 98 THRs (83 pts) still alive, 5 lost to f/u
- 85% retained original prosthesis
- overall 90% retained original prosthesis at f/u or until death
- however, loose on Xray or at revision - 22% cups , 7% stems
- 85% no pain, 14% mild pain, 1% moderate pain
Charnley THR with cement: minimum 25 year follow-up
Callaghan, Albright, Goetz, Olejniczak and
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