The primary aim of this independent prospective randomised trial was to compare serum metal ion levels for ceramic-on-metal (CoM) and metal-on-metal (MoM) bearing surfaces in total hip arthroplasty (THA). Our one-year results demonstrated elevation in metal ion levels above baseline with no significant difference between the CoM and MoM groups. This paper reviews the five-year data.
The implants used in each patient differed only in respect to the type of femoral head (ceramic or metal). At five-year follow-up of the 83 enrolled patients, data from 67 (36 CoM, 31 MoM) was available for comparison.
The mean serum cobalt (Co) and chromium (Cr) ion levels remained above baseline in both groups (CoM: Co 1.16 μg/l (0.41 to 14.67), Cr 1.05 μg/l (0.16 to 12.58); MoM: Co 2.93 μg/l (0.35 to 30.29), Cr 1.85 μg/l (0.36 to 17.00)) but the increase was significantly less in the CoM cohort (Co difference p = 0.001, Cr difference p = 0.002). These medium-term results, coupled with lower revision rates from national joint registries, suggest that the performance of CoM THA may be superior to that of MoM.
While both bearing combinations have since been withdrawn these results provide useful information for planning clinical surveillance of CoM THAs and warrants continued monitoring. Cite this article: Bone Joint J 2017;99-B:1298-1303.
This research output has an Altmetric Attention Score of 2. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 10 January 2018.
All research outputs
#22,981,424
of 34,411,289 outputs
Outputs from The Bone & Joint Journal
#4,572
of 5,771 outputs
Outputs of similar age
#222,582
of 361,887 outputs
Outputs of similar age from The Bone & Joint Journal
#26
of 39 outputs
Altmetric has tracked 34,411,289 research outputs across all sources so far. This one is in the 32nd percentile – i.e., 32% of other outputs scored the same or lower than it.
So far Altmetric has tracked 5,771 research outputs from this source. They typically receive more attention than average, with a mean Attention Score of 8.6. This one is in the 19th percentile – i.e., 19% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 361,887 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 37th percentile – i.e., 37% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 39 others from the same source and published within six weeks on either side of this one. This one is in the 30th percentile – i.e., 30% of its contemporaries scored the same or lower than it.
