title: A longitudinal study of MARS MRI scanning of soft-tissue lesions around metal-on-metal total hip arthroplasties and disease progression.
abstract: We investigated the changes seen on serial metal artefact reduction magnetic resonance imaging scans (MARS-MRI) of metal-on-metal total hip arthroplasties (MoM THAs). In total 155 THAs, in 35 male and 100 female patients (mean age 70.4 years, 42 to 91), underwent at least two MRI scans at a mean interval of 14.6 months (2.6 to 57.1), at a mean of 48.2 months (3.5 to 93.3) after primary hip surgery. Scans were graded using a modification of the Oxford classification. Progression of disease was defined as an increase in grade or a minimum 10% increase in fluid lesion volume at second scan. A total of 16 hips (30%) initially classified as 'normal' developed an abnormality on the second scan. Of those with 'isolated trochanteric fluid' 9 (47%) underwent disease progression, as did 7 (58%) of 'effusions'. A total of 54 (77%) of hips initially classified as showing adverse reactions to metal debris (ARMD) progressed, with higher rates of progression in higher grades. Disease progression was associated with high blood cobalt levels or an irregular pseudocapsule lining at the initial scan. There was no association with changes in functional scores. Adverse reactions to metal debris in MoM THAs may not be as benign as previous reports have suggested. Close radiological follow-up is recommended, particularly in high-risk groups.
authors.affiliation: Hampshire Hospitals NHS Foundation Trust, Aldermaston Rd, Basingstoke, UK.
authors.forename: T W
authors.initials: TW
authors.lastname: Briant-Evans
authors.affiliation: Hampshire Hospitals NHS Foundation Trust, Aldermaston Rd, Basingstoke, UK.
authors.forename: N
authors.initials: N
authors.lastname: Lyle
authors.affiliation: Hampshire Hospitals NHS Foundation Trust, Aldermaston Rd, Basingstoke, UK.
authors.forename: S
authors.initials: S
authors.lastname: Barbur
authors.affiliation: Derby Teaching Hospital, Uttoxeter New Road, Derby DE22 3NE, UK.
authors.forename: J
authors.initials: J
authors.lastname: Hauptfleisch
authors.affiliation: University of Oxford, Nuffield Orthopaedic Centre, Windmill Road, Oxford OX3 7LD, UK.
authors.forename: R
authors.initials: R
authors.lastname: Amess
authors.affiliation: Hampshire Hospitals NHS Foundation Trust, Aldermaston Rd, Basingstoke, UK.
authors.forename: A R
authors.initials: AR
authors.lastname: Pearce
authors.affiliation: Hampshire Hospitals NHS Foundation Trust, Aldermaston Rd, Basingstoke, UK.
authors.forename: K S
authors.initials: KS
authors.lastname: Conn
authors.affiliation: Hampshire Hospitals NHS Foundation Trust, Aldermaston Rd, Basingstoke, UK.
authors.forename: G J
authors.initials: GJ
authors.lastname: Stranks
authors.affiliation: Hampshire Hospitals NHS Foundation Trust, Aldermaston Rd, Basingstoke, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: Britton
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D016477:Artifacts; D003035:Cobalt / Q000097:blood; D018450:Disease Progression; D005260:Female; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D061825:Metal-on-Metal Joint Prostheses / Q000009:adverse effects*; D008875:Middle Aged
chemical_list: D003035:Cobalt
keywords: Follow-up; Longitudinal; MARS; MRI; Metal-on-metal; Pseudotumours; Total hip arthroplasty