Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Arthroplasty - Hip
Abstract number: 26144
METAL ION LEVELS AND ASSOCIATED CHROMOSOME ABERRATIONS IN
METAL-ON-METAL TOTAL HIP ARTHROPLASTIES
Kieran GALLAGHER, Ben SPIEGELBERG, Sammy HANNA, T W R BRIGGS
Royal National Orthopaedic Hospital, London (UNITED KINGDOM)
Metal-on-metal arthroplasties are being increasingly inserted in younger patients due
to the increased durability and reduced requirement for revision in these implants.
Recent studies have raised many concerns over possible genotoxicity of MoM
implants. This is a prospective study of patients who have undergone elective total
hip replacement, they were selected and then randomised into two groups. Group A
received a MoP implant and group B received a MoM implant. Patients are reviewed
pre-operatively (control group), at 3 months, 6 months, 1 year and 2 years postoperatively.
Blood tests are taken to quantify metal ion levels (chromium, cobalt,
titanium, nickel and vanadium) using HR-ICPMS method and chromosome
aberrations in T lymphocytes using 24 colour fluorescent in situ hybridisation (FISH).
53 patients have been recruited to date. 24 of whom had MoP prosthesis and 29 a
MoM. 34 of these have had their one year follow-up with blood analysis and 10 have
had 2 year follow up. Cobalt and chromium concentration increased during the first 6
months in both MoM and MoP groups, in the MoM group the chromium levels were
twice that of MoP group and 12x that of the preoperative samples. Chromosome
aberrations occurred in both groups. At 6 months both the MoM and MoP groups
showed increase frequency of aneuploidy aberrations with further increases after one
year. Structural damage in the form of translocations occurred in the MoM group after
one year, but not in the MoP group, by two years there was a profound increase in
translocations
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