Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Arthroplasty - Hip
Abstract number: 25010
CONTEMPORARY VIEW AT THR USING METAL-ON-METAL BEARINGS OF
ANATOMICAL SIZES
Nikolai ZAGORODNIY , Kyrillos HADJICHARALAMBOUS, Inar SEIDOV, Nik WEYAL,
Denis ELKIN, Sergei BEZVERKHIY, Timofei SKIPENKO, Levon MAKINYAN
Peoples’ Friendship University of Russia, Chair of Traumatology & Orthopaedics,
Moscow (RUSSIA)
More than 575 publications have been made in the leading forums and journals from
2004 to 2005 concerning THR with metal-on-metal bearings using modular
components of anatomical sizes. Older designs of THR implants do not meet the
expectations placed upon them by increased demands. New technologies enable the
achievement of equal or better characteristics of MoM bearings, than UHMWPE and
ceramic bearings. This has led to extended indications for THR and an increase in
the number of procedures, using metal-on-metal bearings of anatomical sizes. In
Sweden, the number of patients younger than 50 years old undergoing primary THR
rose 6% from 2002 to 2004. In Canada, there was an increase of 11% of primary
THRs in patients younger than 45 years of age in 2002 in comparison with 1994. On
the down side, metal-on-metal bearings are susceptible to galvanic corrosion,
abrasion and fretting. While the volumetric wear of polyethylene is greater than that
of MoM bearings, the smaller metallic wear particles produce soluble metallic ions.
High serum levels of metallic ions such as cobalt, chrome and molybdenum may
have a cytotoxic, mutagenic, cancerogenic and immune-modulating effect, although
currently there is no consensus on the matter. In our Clinic we widely use MoM
bearings for THR in the younger, high-demand patients since for the time being the
pros outweigh the possible cons. On the other hand, we refrain from using these
bearings in patients with systemic diseases, altered immune status, renal
insufficiency, women of childbearing age, until more data becomes available.
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