Tags
DePuy, Fellowship of the Royal College of Surgeons, Food & Drug Administration, Hip Replacement, Journal of Bone and Joint Surgery, Magnetic resonance imaging, metal, Orthopedic surgery
Corrosion at the neck-stem junction as a cause of metal ion release and pseudotumour formation.
Corrosion at the neck-stem junction as a cause of metal ion release and pseudotumour formation
- I. P. S. Gill, FRCS(Tr & Orth), Arthroplasty Fellow1
; - J. Webb, FRCS(Tr & Orth), Consultant Orthopaedic Surgeon2;
- K. Sloan, MSc, Research Co-ordinator1; and
- R. J. Beaver, FRACS, Consultant Orthopaedic Surgeon1
+Author Affiliations
- Correspondence should be sent to Mr R. J. Beaver; e-mail:
Abstract
We present a series of 35 patients (19 men and 16 women) with a mean age of 64 years (36.7 to 75.9), who underwent total hip replacement using the ESKA dual-modular short stem with metal on-polyethylene bearing surfaces. This implant has a modular neck section in addition to the modular head. Of these patients, three presented with increasing post-operative pain due to pseudotumour formation that resulted from corrosion at the modular neck-stem junction. These patients underwent further surgery and aseptic lymphocytic vaculitis associated lesions were demonstrated on histological analysis.
Retrieval analysis of two modular necks showed corrosion at the neck-stem taper. Blood cobalt and chromium levels were measured at a mean of nine months (3 to 28) following surgery. These were compared with the levels in seven control patients (three men and four women) with a mean age of 53.4 years (32.1 to 64.1), who had an identical prosthesis and articulation but with a prosthesis that had no modularity at neck-stem junction. The mean blood levels of cobalt in the study group were raised at 50.75 nmol/l (5 to 145) compared with 5.6 nmol/l (2 to 13) in control patients.
Corrosion at neck-stem tapers has been identified as an important source of metal ion release and pseudotumour formation requiring revision surgery. Finite element modelling of the dual modular stem demonstrated high stresses at the modular stem-neck junction. Dual modular cobalt-chrome hip prostheses should be used with caution due to these concerns.
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Which is exactly where I can see evidence of abrasive activity, Earl, inside of the tapered modular ‘sleeve’ on my desk which was affixed around that very neck-stem. I am increasingly concerned that the femoral implant and neck that was ‘re-used’ in my revision is what is still giving me such intense pain, as this recovery is not at all like the first surgery. I am beginning to think that stem was abraded to the point where it too should have been taken from my body, as another pseudotumor has now appeared around my latest implant (Metal modular head into Polyethylene acetabular cup), as recently seen in MRI images taken late last month.
My surgeon contends it’s ‘residual’ fluid, if you will, expecting me to find solace in the fact that the AVAL is smaller this time! “Fantastic, doc, but wasn’t it excised at revision”?, I asked. Disturbingly, my (whose?) doctor offered no reply, and I got the distinct impression HE DID NOT HAVE ONE.
And so goes the continuing saga of ‘hip hell’ up here, from which at times it feels I will never ascend. I don’t know whether to cry or scream — well, actually, screaming might lead to anger, which might lead to me lashing out and injuring myself, such that I require yet another surgery in a different part of my body (he wrote, typing with but one functional hand).
That currently leaves crying (in pain) as my only viable option. Oh well, back to bed, where most pain disappears, and I sometimes dream I’m running along forest trails. I love that dream while immersed in it, but am crestfallen upon awakening to the dull, throbbing pain that is my hip. — nay, that has become my world!
I feel as if I must change that to pull out of this nose-dive.
Brooks – didn’t realise they had reused the stem. Not a good move – I think you have your answer. Now to find someone who will believe you.
I had the stem head and cup replaced. Got rid of the S&N shit.
Earl
Yeah Earl, they convinced me of the incredible versatility of their wonderful Smith and Nephew femoral ‘system’, and how easy it would be to revise without disturbing the femur. I bought it man. Hook, line and sinker. And when I read this post of yours I too knew the truth (in my gut). This conclusion had been sneaking up on me for awhile, as after receiving my revision records I found the surgeon’s chart notes on the matter. In those recently discovered notes, he says, and I paraphrase, “The neck appears well-placed, and the small amount of visible abrasive activity is low enough so as to safely warrant using the stem in revision”. They don’t give the details until after the fact.
So once again I have been hoodwinked, another time hornswoggled by this Corporate Health Care System. I was all too willing to avoid messing around with that femoral component, because it exposes the ‘revisee’ (in this case me) to oh so much more pain.
Well sir, I now wish I had discussed with you this matter and its risky implications beforehand, as opposed to after the fact. Once again I find I’m a day late and a dollar short! How can you not get riled when you’ve been had? I shouldn’t have trusted them, but then again, this is the top hospital in five states out here and ‘the best of the best’, etc., so forth and so on, ad infinitum (ad nauseum).
Bottom line is that hindsight is always a perfect 20-20, and the last thing I need to add to my platter right now is another heaping helping of regret and very critical second-guessing. But I am pissed at myself for this act of sheer stupidity, just complete gullibility on my end.
Well, yes, now we all know, don’t we? Have ’em yank the whole poisonous piece of crap outta there and start anew. Good lord, man! It seems like we learn something six months after we needed to know it. It’s all falling apart though, and the Ivory Tower telling me to proceed in such and such a manner belies their professionally informed impartiality, so called. To me it reveals either a physician uninformed or (to whatever degree) complicit, at least in this specific revision. I trusted them, and as a 59 year old I had been inculcated to ‘trust the doctor’ throughout my youth and onward.
I now feel as if everything has been of a disguise, a sleight of hand, a well-played ruse. All a deliberate act of obfuscation. Their over-arching edict seems to be that the patient must be kept in the dark, at whatever the cost. Because he — and only he — is the only one to carries that cost. The burden is now placed squarely on our backs; Caveat Emptor! Even when advised in the hospital by those who have taken the Hippocratic Oath.
Who’s to protect us? Perhaps we simply don’t matter. Expendable. Like a product.
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