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.
Subject(s)
Arthroplasty, Replacement, Hip/methods , Hip Prosthesis/adverse effects , Magnetic Resonance Imaging/methods , Metal-on-Metal Joint Prostheses/adverse effects , Adult , Aged , Aged, 80 and over , Artifacts , Cobalt/blood , Disease Progression , Female , Humans , Longitudinal Studies , Male , Middle AgedABSTRACT
We describe two cases of fracture of Corin Taper-Fit stems used for cement-in-cement revision of congenital dysplasia of the hip. Both prostheses were implanted in patients in their 50s, with high offsets (+7.5 mm and +3.5 mm), one with a large diameter (48 mm) head and one with a constrained acetabular component. Fracture of the stems took place at nine months and three years post-operatively following low-demand activity. Both fractures occurred at the most medial of the two stem introducer holes in the neck of the prosthesis, a design feature that is unique to the Taper-Fit stem. We would urge caution in the use of these particular stems for cement-in-cement revisions.
Subject(s)
Arthroplasty, Replacement, Hip/methods , Hip Dislocation, Congenital/surgery , Hip Prosthesis , Acetabulum/surgery , Bone Cements , Female , Femur/surgery , Humans , Middle Aged , Prosthesis Failure , Reoperation , Treatment OutcomeABSTRACT
Local recurrence in breast cancer surgery is related to the completeness of excision. Histological analysis of excision margins is time consuming and impractical for use intra-operatively. Our group evaluated breast imprint and scrape cytology (ISC) for the assessment of excision margins in a feasibility study in 1993-4, with 10 year clinical follow-up. Twenty-six consecutive women undergoing 27 wide local excisions for breast cancer had excision margins prospectively assessed with intra-operative ISC blinded to histology. All ISC results were ready (range 22-30 min) before surgery was completed. ISC agreed with histology in 21/27 (=78%) and disagreed in 6/27 (=22%) of the cases. In two cases with local recurrence, histology was positive in one case, whereas ISC margins were positive in both. Intra-operative ISC is reliable and could help the surgeon to excise more tissue to prevent a second (re-excision) operation. ISC margins may predict clinical outcome, although a larger interventional follow-up study is required.
