Review of the 2010 Australian Joint Registry Results for hips having higher than anticipated revision rates(4 of 4) : The Depuy ASR

1)  Reason for revision of the ASR vs other total conventional hips

Revision diagnosis	ASR number	ASR %revision	ASR % of all primary procedures	Other conventional hips (number)	Other conventional hip revisions  (% revision)	Other conventional hips (% primary)
Loosening/lysis	92	43.8%	2.1%	1427	29.3%	.9%
Prosthesis dislocation	15	7.1%	.3%	1385	28.5%	.8%
infection	42	20%	1%	804	16.5%	.5%
fracture	19	9%	.4%	725	14.9%	.4%
pain	7	3.3%	.2%	97	2%	.1%
Other (14 categories)	35	16%	.9%	429	1%	0
revisions	210	100%	4.8%	4867	100%	2.9%
Primary	4406			16,698

[ comments from connie: When you look at these numbers, you begin to see why a surgeon would have used this  Depuy ASR device.  This chart shows several likely reasons:

• Prosthesis dislocation is 400% higher in the Other hips vs Depuy ASR
• Fracture is 60% higher in the other hips vs the Depuy ASR

On the other side of the equation, you can see the downside:

• loosening of the prosthesis and lysis is about 70% higher in the Depuy ASR (Lysis (Greek λύσις, lýsis from lýein "to separate") refers to the breaking down of a cell, often by viral, enzymic, or osmotic mechanisms that compromise its integrity)

You have to pick your risks.  The surgeon likely looked at younger patients who were more active-like me- and chose the hip with the lower chance of dislocating and fracture.  Unfortunately, as it turned out, in the long run, the lysis turned out to be a major issue.

This little exercise reaffirms the concept that with every reward in medicine there are risks.  Somehow, surgeons have to balance them out sometimes absent complete information.]

2.  Number of revisions of ARS by year of implant (remember the data here is all from Australia joint registry.)  Note:  Primary procedures performed in later years have had less follow up time therefore the number revised is expected to be less than the number revised in early years which is why you wouldn't calculate percents.

In the early years, you can see that the percents are relatively high comparatively:

• 4.7% /2004
• 7%/ 2005

Year of Implant	Number revised	Total Number
2004	4	84
2005	41	583
2006	60	958
2007	56	2284
2008	45	1172
2009	4	425
total	210	4406

this is kind of interesting as well because if you look at the calculation of these rates in the last few posts, something seems to be incongruous...not sure what?  Likely the cumulative numbers would be better to look at not the annual numbers.  These were published in the last few posts.

Anyway, this was very interesting especially the first point above.  It provides perspective on the surgeon's dilemma doesn't it?