Metal Artifact Reduction Sequence MRI Abnormalities Occur in Metal-on-polyethylene Hips

Abstract

Background To determine the importance of MRI abnormalities in metal-on-metal (MoM) bearings, it is important to understand the baseline features of this diagnostic tool in conventional metal-on-polyethylene (MoP) bearings.Questions/purposes What are the frequency, size, and types of MRI-documented adverse local tissue reactions in asymptomatic patients with MoP bearings? Methods We recruited 50 patients 5 years after a MoP total hip arthroplasty from a pool of patients in our joint registry who had a Harris hip score of [ 90. To be included, patients had to be without pain and have adequate radiographs. Our data set included 50 asymptomatic patients with MoP bearings who underwent a metal artifact reduction sequence MRI. Results MRI abnormalities were seen in 14 of 50 (28%) asymptomatic patients who were studied. Thirteen of the 14 abnormalities were cystic thin-walled lesions with a mean of 18 cm 3 (range, 1-79 cm 3 ). Conclusions MRI abnormalities were noted in nearly one-third of asymptomatic patients with MoP bearings. Decisions concerning revision of MoM bearings should not be based on isolated MRI findings because MRI abnormalities are commonly seen regardless of bearing type. A number of factors should determine the need for intervention including pain, mechanical symptoms, abductor weakness, component type, component position, and ion levels as well as MRI findings.

Standardizing terms for tribocorrosion-associated adverse local tissue reaction in total hip arthroplasty

“…Aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) is not a clinical diagnosis; however, it represents histological appearance of tissues characterized by lymphocyte infiltration and perivascular cuffing [9]. Fluid alone on an MRI may be interpreted as an adverse local tissue reaction (ALTR) [10,11], and systems to grade these MRI changes show only moderate agreement among reviewers [12]. A group of other such terms and test parameters, often adopted from research of failed metal-on-metal (MoM) hip arthroplasties, adds to confusion in this field ( Table 1).…”

“…3). Reactions may include osteolysis, bone necrosis, muscle necrosis, tendon necrosis with or without detachment, capsular necrosis with or without dehiscence, capsular thickening, cystic lesion(s), excessive fluid collection(s), ALVAL, and soft tissue masses [10,11,[33][34][35][36][37]. Many of these features are seen in variable amounts in cases of ALTR and it is not clear why some lesions show a predominance of one feature over the others.…”

“…A serum Co of >1 ppb has been shown to be associated with both tribocorrosion and associated ALTR [34,37]. It is acknowledged that MRI abnormalities may not be significant in patients without MACC [10], but such findings are likely to be important in patients with MACC [3,19].…”

Adaptive SAR mass‐averaging framework to improve predictions of local RF heating near a hip implant for parallel transmit at 7 T

“…Magnetic resonance imaging is being used increasingly for the diagnosis of complications after total hip replacements . The introduction of metal artifact reduction sequences enables the excellent contrast between soft tissues available with MRI to assess the presence of pathology in cases in which conventional radiographs are considered normal . In addition, the number of patients aged 45 and over undergoing total hip replacement has doubled between 2000 and 2010 in the United States, with numbers expected to grow over the next decade .…”

Radiofrequency safety and shimming near metal hip prostheses at high and ultra-high field

“…Magnetic resonance imaging is being used increasingly for the diagnosis of complications after total hip replacements (THR) [15,77]. The introduction of metal artefact reduction sequences [11,13,189] enables the excellent contrast between soft tissues available with MRI to assess the presence of pathology in cases where conventional radiographs are considered normal [10,176]. In addition, the number of patients aged 45 and over undergoing THR has doubled between 2000 and 2010 in the US, with numbers expected to grow over the next decade [9].…”