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Updated: May 18, 2026
Protocol for the Evaluation of MRI Artifacts Caused by Metal Implants to Assess the Suitability of Implants and the Vulnerability of Pulse Sequences
Published on: May 17, 2018
MRI findings in painful metal-on-metal hip arthroplasty
Catherine L Hayter1, Stephanie L Gold, Matthew F Koff
1Department of Radiology and Imaging, Hospital for Special Surgery, Weill Cornell Medical College of Cornell University, 535 E 70th St, New York, NY 10021, USA.
Objective:
The objective of our study was to compare the frequency of osseous and soft-tissue abnormalities in patients presenting with hip pain after resurfacing arthroplasty and after total hip arthroplasty (THA), correlate the MRI findings with histologic results, and determine which MRI findings are predictive of aseptic lymphocytic vasculitis-associated lesions.
Materials And Methods:
The MRI examinations of patients with metal-on-metal hip prostheses placed at resurfacing arthroplasty (n=31) or THA (n=29) were reviewed for osteolysis, synovitis, extracapsular disease, synovial pattern, and mode of decompression into adjacent bursae. Regional muscles and tendons were assessed for tendinosis, tear, atrophy, and edema. Histologic and operative findings were reviewed in 19 patients (20 hips) who underwent revision surgery. Chi-square tests were performed to detect differences between the resurfacing arthroplasty and THA groups. The Wilcoxon rank sum test was performed to detect differences in MRI findings in patients with and those without aseptic lymphocytic vasculitis-associated lesions.
Results:
Synovitis was detected in 77.4% of resurfacing arthroplasty hips and 86.2% of THA hips. Extracapsular disease was present in 6.5% of resurfacing arthroplasty hips and 10.3% of THA hips. Osteolysis was detected in 9.7% of resurfacing arthroplasty hips and 24.1% of THA hips. There was no difference in the incidence of synovitis (p=0.51), osteolysis (p=0.17), or extracapsular disease (p=0.67) between the resurfacing arthroplasty and THA groups. Patients with aseptic lymphocytic vasculitis-associated lesions had higher volumes of synovitis (p=0.04) than patients without aseptic lymphocytic vasculitis-associated lesions. Extracapsular disease and muscle edema were seen only in patients with aseptic lymphocytic vasculitis-associated lesions.
Conclusion:
Synovitis is common in patients with metal-on-metal hip prostheses and occurs with a similar incidence after resurfacing arthroplasty and after THA; osteolysis and extracapsular disease are uncommon. The MRI signs most suggestive of aseptic lymphocytic vasculitis-associated lesions are high volumes of synovitis, extracapsular disease, and intramuscular edema.
Insights
Synovitis is common in metal-on-metal hip implants, with similar rates after resurfacing arthroplasty and total hip arthroplasty (THA). MRI findings like extensive synovitis and extracapsular disease may indicate aseptic lymphocytic vasculitis-associated lesions.
Area of Science:
- Orthopedic Surgery
- Radiology
- Biomaterials Science
Background:
- Metal-on-metal hip prostheses, including resurfacing arthroplasty and total hip arthroplasty (THA), are used to treat hip conditions.
- Patients may experience hip pain post-implantation, necessitating investigation of potential complications.
- Aseptic lymphocytic vasculitis-associated lesions (ALVAL) are a concern in metal-on-metal implants.
Purpose of the Study:
- To compare osseous and soft-tissue abnormalities between hip resurfacing and THA using MRI.
- To correlate MRI findings with histologic results in revision surgeries.
- To identify MRI predictors of aseptic lymphocytic vasculitis-associated lesions (ALVAL).
Main Methods:
- Retrospective review of MRI examinations in 31 hip resurfacing and 29 THA patients with metal-on-metal prostheses.
- Assessment for osteolysis, synovitis, extracapsular disease, and muscle/tendon abnormalities.
- Correlation of MRI findings with histologic data from 20 revision surgeries and statistical analysis.
Main Results:
- Synovitis was common (77.4% resurfacing, 86.2% THA), with no significant difference between groups.
- Osteolysis and extracapsular disease were infrequent and similar between groups.
- Higher synovitis volumes and the presence of extracapsular disease/muscle edema were associated with ALVAL.
Conclusions:
- Synovitis is a frequent finding in metal-on-metal hip prostheses, irrespective of implant type (resurfacing vs. THA).
- Osteolysis and extracapsular disease are uncommon complications.
- MRI findings suggestive of ALVAL include significant synovitis, extracapsular disease, and intramuscular edema.
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