Metal Artifact Reduction Sequence Magnetic Resonance Imaging Abnormalities in Asymptomatic Patients With a
Jason M Jennings1, Gregory J Czuczman2, Roseann M Johnson3
1Colorado Joint Replacement, Porter Adventist Hospital, Denver, CO; Department of Biomedical Engineering, University of Denver, Denver, CO.
Background:
Metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) has recently gained increased utilization as a screening modality in patients with a total hip arthroplasty (THA). Fluid collections have been documented in asymptomatic patients with various bearing surfaces. The purpose of this study is to determine the frequency and types of MARS MRI-documented abnormalities in asymptomatic patients with a ceramic-on-ceramic (CoC) THA.
Methods:
Thirty-seven patients (42 hips) with a minimum 2-year follow-up after THA with CoC THA implants were enrolled in this study. The inclusion criteria were the absence of hip pain and the availability of appropriate follow-up radiographs. All patients underwent a MARS MRI. Abnormalities were documented using a previously described method.
Results:
Fluid collections were observed in 8 (19%) asymptomatic hips in this cohort. Four of the 8 hips demonstrated intracapsular synovitis, and 3 of these hips had a thickened synovium. Extra-articular fluid collections with direct intra-articular communication were identified in 4 hips, with 2 of these hips demonstrating synovial thickening. No signs of osteolysis were noted on radiographs or the MARS MRI scans.
Conclusion:
Asymptomatic fluid collections occur in patients after CoC THA similar to other bearing surfaces. We continue to follow these patients in an effort to determine the clinical significance and natural history of these findings.
Level Of Evidence:
Diagnostic Level IV.
Insights
Asymptomatic fluid collections are common in patients with ceramic-on-ceramic total hip arthroplasty (THA) implants, as seen on Metal Artifact Reduction Sequence (MARS) MRI. Further research will determine the clinical significance of these findings.
Area of Science:
- Orthopedic Surgery
- Radiology
- Biomaterials Science
Background:
- Metal Artifact Reduction Sequence (MARS) magnetic resonance imaging (MRI) is increasingly used for screening patients with total hip arthroplasty (THA).
- Fluid collections have been observed in asymptomatic patients with various THA bearing surfaces.
- Ceramic-on-ceramic (CoC) THA is a common bearing surface, but the prevalence of MRI-detected abnormalities in asymptomatic patients is not well-established.
Purpose of the Study:
- To determine the frequency and types of abnormalities detected by MARS MRI in asymptomatic patients with CoC THA.
- To characterize fluid collections and assess for osteolysis in this patient cohort.
Main Methods:
- Thirty-seven patients (42 hips) with at least a 2-year follow-up after CoC THA and no hip pain were included.
- All patients underwent MARS MRI.
- Abnormalities were documented using a standardized method, and radiographs were reviewed for osteolysis.
Main Results:
- Fluid collections were identified in 19% (8 of 42) of asymptomatic hips.
- Intracapsular synovitis was present in 4 hips, with synovial thickening in 3.
- Extra-articular fluid collections with intra-articular communication were found in 4 hips, with synovial thickening in 2.
- No osteolysis was detected on radiographs or MARS MRI.
Conclusions:
- Asymptomatic fluid collections are a common finding after CoC THA, similar to other bearing surfaces.
- The clinical significance and natural history of these fluid collections require ongoing investigation.
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