Two-year Study of serum metal ion levels in hipresurfacing 2014
Two-year serum metal ion levels in minimally invasive total conservative hip
resurfacing: preliminary results of a prospective study
Tai SM1, Millard N, Munir S, Jenabzadeh AR, Walter LR, Walter WL.
Complete Study
http://www.ncbi.nlm.nih.gov/pubmed/25288230
Metal-on-metal (MoM) hip resurfacings have been associated with the potential
development of metallic debris and its associated pathology. Serum cobalt and
chromium levels are a reliable surrogate marker of wear rates in MoM bearings.
The aim of the study was to examine the trend in serum metal ion levels in the
initial 2-year post-operative period following implantation of the minimally
invasive total conservative hip MoM hip resurfacing and to determine whether
head size, acetabular component orientation, clinical outcome scores or
post-operative range of movement would affect these levels.
METHODS:
In this prospective cohort study, serum cobalt and chromium ion levels were
measured pre- and post-operatively in 25 patients who underwent minimally
invasive total conservative hip MoM hip resurfacing. The results were correlated
with acetabular component orientation, head size, outcome scores and
post-operative range of movement.
RESULTS:
The mean serum cobalt and chromium levels at 2 years were 1.2 ppb (0.4-4.4 ppb)
and 2.1 ppb (0.7-5.7 ppb). The mean cup inclination was 43° (30°-60°) and
anteversion was 18° (1°-47°). There was no clear relationship between serum ions
and acetabular component orientation, outcome scores or range of movement.
Patients with a head size ≤52 mm had significantly higher metal ion levels
(cobalt P = 0.02, chromium P = 0.045).
CONCLUSION:
Our preliminary results show all patients had cobalt and chromium levels below
those indicating a high-risk implant, suggesting successful early outcome from
minimally invasive total conservative hip resurfacing surgery.