Ceramic-on-metal (CoM) is a relatively new bearing
combination for total hip arthroplasty (THA) with few reported outcomes.
A total of 287 CoM THAs were carried out in 271 patients (mean age
55.6 years (20 to 77), 150 THAs in female patients, 137 in male)
under the care of a single surgeon between October 2007 and October
2009. With the issues surrounding metal-on-metal bearings the decision
was taken to review these patients between March and November 2011,
at a mean follow-up of 34 months (23 to 45) and to record pain,
outcome scores, radiological analysis and blood ion levels. The
mean Oxford Hip Score was 19.2 (12 to 53), 254 patients with 268
hips (95%) had mild/very mild/no pain, the mean angle of inclination
of the acetabular component was 44.8o (28o to
63o), 82 stems (29%) had evidence of radiolucent lines
of >
1 mm in at least one Gruen zone and the median levels of cobalt
and chromium ions in the blood were 0.83 μg/L (0.24 μg/L to 27.56 μg/L)
and 0.78 μg/L (0.21 μg/L to 8.84 μg/L), respectively. The five-year
survival rate is 96.9% (95% confidence interval 94.7% to 99%). Due to the presence of radiolucent lines and the higher than
expected levels of metal ions in the blood, we would not recommend
the use of CoM THA without further long-term follow-up. We plan
to monitor all these patients regularly. Cite this article:
