In a randomized study of 60 patients allergic reactions are evaluated in three joint prosthesis groups, a resurfacing arthroplasty (ReCap), a non-cemented, large metal-on-metal head (Bimetric Magnum) and a non-cemented, alumina ceramic-on-ceramic bearing in a titanium shell (Bimetric C2a). The inclusion criteria were osteoarthritis, ASA I–II, MRI-scan without caput necrosis, DXA-scan without osteoporosis. The exclusion criteria were short neck (<2cm.), large cysts (>1cm.), medical treatment affecting the bone metabolism, severe deformity of the femoral head, impaired kidney function and inability to co-operate. Blood samples were drawn prior to and 6 weeks, 6 months, 1 year, and 3 years after surgery; two tubes from which plasma was prepared, and two tubes for serum. From the last included 20 patients in each group was also taken blood one and three years after surgery for an in vitro lymphocyte assay for scoring of possible hypersensitivity to prosthesis metals. The isolated lymphocytes were subjected to measurement of proliferation and expression of CD69 by flow cytometry and measurement of the Migration Inhibitory Factor (MIF) by ELISA. Plasma concentrations of the cytokines IL-1, IL-4, IL-6, IL-8, IL-12p70, IL-15, interferon-and osteoprotegerin were determined by multiplex-immunoassay. Serum concentrations of chromium and cobalt were determined by graphite furnace atomic absorption spectrometry. The serum concentrations of chromium and cobalt were lowest in patients with the C2a implant and highest with Magnum, some of these differences were significant at 6 weeks, 6 months, and 1 year after surgery. No patient had a very high serum metal concentration. The values of the variables measured in the in vitro lymphocyte assay mainly changed in the expected direction depending on the concentration of the same metal in the serum sample drawn at the same time, but no significant correlation was seen. One patient had uncertain symptoms of metal hypersensitivity and relatively high serum metal concentrations 3 years after arthroplasty with a Magnum prosthesis and was assessed extraordinarily, and elicited the marginally highest MIF responses in the lymphocyte assay. A strong correlation was found between the plasma concentrations of most cytokines, but the cytokine concentrations were not correlated to contemporary metal concentrations.
To compare regional body composition, bone mineral density (BMD), and clinical outcome in patients with two different shoulder arthroplasty designs. This cross-sectional study included 54 patients with a total of 63 shoulder arthroplasties. There were 18 men and 45 women with a mean age of 68.9 years SD ± 10.5. Mean follow-up time was 39.2 months SD ± 14.4. The patients were divided into three groups according to their history: 22 patients were diagnosed with a proximal humeral fracture and treated with a stemmed hemi arthroplasty, 11 patients were diagnosed with osteoarthritis and treated with a stemmed hemi arthroplasty, and 30 patients were diagnosed with osteoarthritis and treated with a resurfacing arthroplasty. All patients underwent a one-day protocol: Regional Dual X-ray Absorptiometri (DXA) was used to measure BMD of the distal third of humerus and regional body composition of the upper arm. The clinical outcome was measured using Western Ontario Osteoarthritis of the Shoulder index (WOOS) and Constant-Murley score.Objective
Materials and Methods
