Australian Joint Registry Report

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The results of the Australian Joint Registry as summarised by Dr George Thomas,Consultant Orthopaedic Surgeon, St.Isabel Hopsital, Chennai and also Editor, Indian Journal of Medical Ethics
  • It is now clear that primary total conventional hip  replacement using metal on metal bearing surface and  head sizes over 28mm have a higher risk of revision compared to all other bearing surfaces. The impact of  head size is more apparent in head sizes greater than 32mm.
  • The increased risk of revision of metal on metal  bearing surface is due to higher rates of loosening and  metal sensitivity. It is not age related. There is  however an interaction between age and head size.  The risk of revision for head sizes larger than 32mm is  higher regardless of age and this risk is greater the younger the patient.
  • The use of primary total resurfacing hip replacement has declined for the fourth consecutive year. There was a 17.6% reduction in primary total resurfacing procedures compared to 2008.
  • Posterior stabilised primary total knees are revised  more than minimally stabilised knees. The risk of revision in the first nine years is increased if the patella is not resurfaced and this risk is highest if a  posterior stabilised prosthesis is used.
  • The S-Rom/Duraloc combination has been used in 166 procedures and has a seven year cumulative percent revision of 6.9%. It has two and a half times the risk of revision compared to all other total conventional hip replacement (adj HR=2.46; 95%CI (1.54, 3.91), p<0.001). Seven of the 18 revisions were for loosening and six for lysis.
  • The CLS/Trilogy combination and the Anca Fit femoral stem have been previously identified prostheses. This year’s analysis shows no significant difference in the revision rate compared to all other total conventional hip replacement (CLS/Trilogy adj HR=1.90; 95%CI (0.95, 3.80), p=0.070; Anca_Fit adj HR=1.84; 95%CI (0.96, 3.54), p=0.067).

 

see the whole report at

http://www.dmac.adelaide.edu.au/aoanjrr/documents/aoanjrrreport_2010.pdf

 

Comments

  1. Dr Dhananajaya says

    At last………….Charnley was not a fool.

    Other important highlight ………….revision rate of bipolar prosthesis is less when compared to unipolar modular prosthesis.

    The bottom line is clear…….cemented bipolar prosthesis is better than unipolar prosthesis. All prosthesis used were modular bipolar, not fixed. Revision rate is only 6 % at 7 years in less than 75 yrs, and 3 % thereafter.

    Interestingly the revision rate after primary THR after fracture neck femur is 6.6% at 7 years ( comparable to bipolar). So the battle for fracture neck femur has been a deuce between modular bipolar & THR.

    Hybrid system had lowest revision rate in total whereas cementless THR has least revision rate after 4 years.

    Modular stem (S-ROM) & surface replacement………..are options for selected candidates; not a answer to all hips. A standard THR has its own place.

    Patellar resurfacing decreases revision rates in TKR>

    I strongly feel that instead of getting biased by newer designs launched every year, surgeons should choose the implant according to the patient characteristic to get good result.

  2. George Thomas, Consultant, St Isabel's hospital,Chennai; Editor Indian Journal of Medical Ethics says

    There is a need for comparison of the findings from the different registries and reconciliation of the results. For example, patella resurfacing is very uncommon in Sweden, with over 95% of knees being done without patella resurfacing.
    Corail is not used in Sweden,but is still popular in UK.
    CLS Spotorno – very good results out to twenty years in Sweden.

    I’m waiting for someone to make sense of these conflicting findings.

    Findings common across all registries:
    Resurfacing does poorly compared to THR and is declining world over.
    Cemented hips do better than uncemented at present.
    Metal on metal has poor results compared to metal on UHMWE.
    Big heads (over 32mm) – more loosening.

    TKR : Standard TKR better than rotating platform, LCS.
    Cemented does better than uncemented and very few uncemented knees done anywhere in the world.

  3. Murali Poduval says

    These results are conflicting in many ways. Take the revision rates of posterior stabilised prosthesis. Increased revision rates in the mid term with not resurfacing the patella need to be analysed in detail, but it does set the ground for the purists who advocate that the patella should always be resurfaced. Increased revision rates for posterior stabilised prosthesis which have a long track record is confusing to say the least.
    The S ROm by itself, at least for me, has limited indications, and since these are complex primaries the expected revision rate may be higher. Despite that, the revision rate of close to seven percent is still cause for concern.
    The metal on metal hips have been seeing a mad see saw of opinions, from the very good to the very bad, but a consistent fall in number of resurfacings must have something to do with the surgeons increasing dissatisfaction with the results of the procedure. There are earlier reports that talk of increasing risk of revision especially with smaller head sizes and in women. Here there is also discussion of head sizes greater than 32 mm and a relation with age, greater revision risk with younger age and larger head sizes, this would turn the entire marketing principle upside down. That larger bearings give better range of motion and better function in younger patients would be difficult to sustain. With the fiasco of two major resurfacing implant recalls in the recent past, this should set the ball rolling back into research. The cause for revision being loosening and metallosis is cause for concern citing that the bearing may be at fault.
    regional differences in implant usage may reflect in different registries and a composite analysis is best when it comes to analysing any implant type, as Dr Thomas rightly suggested and by no means will such an analysis be easy.
    cemented hips still stand the test of time and so does the metal on poly bearing.

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