- Oxinium or otherwise “oxidised zirconium” was suggested as a good bearing surface by Bourne in his article in CORR 2005.
- These oxinium surfaces are derived from a zirconium base that is heated and then infused with oxygen, transforming the outermost layer into a ceramic shell
- This surface possibly combines the fracture resistance of metal, with wear resistance of ceramics
- The major advantage of oxinium is its apparent capacity for reduced wear when coupled as a femoral head component to a polyethylene cup
- Unfortunately not enough long term outcome studies are available for this bearing surface
- Infact, there have been case reports, by Kop et al.. in J Arthroplasty, 2007 and McCalden JBJS(B) 2011 where there is early damage of these ‘oxinium’ components, especially the zirconium bases on which they are built upon.
Further Reading:
1. Damage of an Oxinium femoral head and polyethylene liner following ‘routine’ total hip replacement.
McCalden RW, Charron KD, Davidson RD, Teeter MG, Holdsworth DW.
J Bone Joint Surg Br. 2011 Mar;93(3):409-13.
2. Damage of oxinium femoral heads subsequent to hip arthroplasty dislocation three retrieval case studies.
Kop AM, Whitewood C, Johnston DJ. J Arthroplasty. 2007 Aug;22(5):775-9
3. http://www.ncbi.nlm.nih.gov/pubmed/18848427
4. Arthroplasty options for the young patient: Oxinium on cross linked polyethylene
Bourne RB, Barrack R, Rorabeck CH, Salehi A, Good V.Clin Orthop Relat Res. 2005 Dec;441:159-67.
Dear Hitesh,
Thanks for requesting my opinion.
The articles bring out the fact that the oxinium material is prone for damage if not handled properly. This is a well established fact as oxinium is relatively a softer material. However the advantages of oxinium is its wear properties being significantly superior than that of Co-Cr. This has not been disputed in recent studies. Oxinium heads are relatively cheaper and probably have comparable wear properties as ceramics.
Any material if not handled properly and scratched will give rise to precipitous wear of the poly.
I have attached a link to an an article by Micheal Ries where the same changes occured with a scratched Co_Cr head
Delamination of a highly cross-linked polyethylene liner associated with titanium deposits on the cobalt-chromium modular femoral head following dislocation.
Patten EW, Atwood SA, Van Citters DW, Jewett BA, Pruitt LA, Ries MD.
Bone Joint Surg Br. 2010 Sep;92(9):1306-11.
Therefore the message in these studies is that one must handle all types of femoral heads with great caution and any scratch will have disastrous consequences on the poly.
Oxinium heads are very popular in revision hip surgeries because it can be used with some taper damage ( unlike ceramic heads) and high offset like +8 and +12 are possible unlike ceramics. However these advantages have to be tempered with caution as any dislocation will damage the oxinium heads.
with best regards
vijay bose
chennai
Yes hitesh, Do agree with the comments by Vijay.
Unlike COCR, oxinium scratches do not have the peaks and only have troughs around scratches. it is evident when comparable in vitro studies compared scratched cocr and oxinium on poly simulator studies showed less wear in scratched oxinium.
secondly, there has been issues with metal allergy in various cocr implants even causing arthrofibrosis in TKR (specially in patients having allergy to imitation jewellery). in such cases there may be role for oxinium
there has been some comments on phase transformation in oxinium something which is less understood and not proven.
Oxinium implants are relatively recent entrants into the already confusing world of bearings. I tend to agree with Dr Bose, that the alternative bearings depend on careful handling. The same is true for ceramics, and as far as my limited knowledge goes, with oxinium. I know for a fact that Dr Vijay Bose has implanted some of these, I personally haven’t. I wouldn’t jump to discredit the bearing entirely in such a hurry based on recent isolated reports but would give it some time. Im rather more concerned at the more frequent reports on failure of large head metal bearings at the moment. Oxinium will have its utilities and will have a role in the future, the way I see it.
Dear Hitesh,
Many thanks for asking me to comment on this issue. Although I have NO experience with this bearing, I feel I need to share something with you. Practically speaking, I would be hesitant to start any new technology, in my private practice, unless I am totally convinced that it is very, very safe to my patients. Although I had many requests from my patients, I have not used this bearing simply because I have had no problems with what I have been using so far as they have a very good track record! In India, as we do not have a central safety watchdog , like NICE in the UK, we need to be careful. I have recently done a meta-analysis with Mo Bhandari from Canada (in print) and we felt that the long-time survival at 10 years is good with metal-on-metal bearing. Of course, we need to look at the right indications.
Very best wishes,
Vijay Shetty
Mumbai
oxynium can be used when the patient is allergic to cobalt chrome..
otherwise i do not see the need to pay extra…