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Updated: Jun 22, 2026
Potentiodynamic Corrosion Testing
Published on: September 4, 2016
The painful metal-on-metal hip resurfacing
1Department of Radiology Imperial College, Charing Cross Hospital, London, UK. a.hart@imperial.ac.uk
Abstract:
We carried out metal artefact-reduction MRI, three-dimensional CT measurement of the position of the component and inductively-coupled plasma mass spectrometry analysis of cobalt and chromium levels in whole blood on 26 patients with unexplained pain following metal-on-metal resurfacing arthroplasty. MRI showed periprosthetic lesions around 16 hips, with 14 collections of fluid and two soft-tissue masses. The lesions were seen in both men and women and in symptomatic and asymptomatic hips. Using three-dimensional CT, the median inclination of the acetabular component was found to be 55 degrees and its positioning was outside the Lewinnek safe zone in 13 of 16 cases. Using inductively-coupled plasma mass spectrometry, the levels of blood metal ions tended to be higher in painful compared with well-functioning metal-on-metal hips. These three clinically useful investigations can help to determine the cause of failure of the implant, predict the need for future revision and aid the choice of revision prostheses.
Insights
Investigating unexplained pain after metal-on-metal hip resurfacing, this study found periprosthetic lesions and malpositioned components. Elevated blood metal ion levels correlated with hip pain, aiding in implant failure diagnosis and revision planning.
Area of Science:
- Orthopedic surgery
- Biomaterials science
- Diagnostic imaging
Background:
- Metal-on-metal resurfacing arthroplasty can lead to unexplained pain.
- Identifying the causes of implant failure is crucial for patient outcomes.
Purpose of the Study:
- To evaluate the utility of MRI, 3D CT, and blood metal ion analysis in diagnosing pain after metal-on-metal hip resurfacing.
- To correlate imaging findings and metal ion levels with clinical symptoms.
Main Methods:
- Metal artefact-reduction MRI, 3D CT component positioning, and inductively-coupled plasma mass spectrometry (ICP-MS) for cobalt and chromium in whole blood.
- Analysis of 26 patients with unexplained pain following metal-on-metal resurfacing arthroplasty.
Main Results:
- MRI revealed periprosthetic lesions (fluid collections or soft-tissue masses) in 16 hips.
- 3D CT showed acetabular component inclination outside the Lewinnek safe zone in 13 of 16 cases.
- Blood metal ion levels were generally higher in painful hips compared to well-functioning ones.
Conclusions:
- Combined use of MRI, 3D CT, and ICP-MS is clinically valuable for diagnosing metal-on-metal hip implant failure.
- These investigations can predict the need for revision surgery and guide the selection of revision prostheses.
