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Lactococcus garvieae is a fish pathogen, rarely causing opportunistic infections in humans. There are only a few cases reported in the literature, mainly endocarditis, suggesting an association with raw fish consumption. We report a case of a periprosthetic hip infection successfully treated with a two-stage revision surgery.
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BACKGROUND: Periprosthetic bone remodelling may increase fracture risk and deplete bone stock around hip implants. These changes are in part caused by implant design, advocating an early evaluation of bone remodelling properties of new implants. This can be done by repeated dual-energy x-ray absorptiometry (DXA) measurements. We know that radiopaque cement falsely elevates bone mineral density (BMD) in single measurements, however, its impact on repeated measurements, i.e. BMD changes is unexplored. We have therefore investigated whether the presence of radiopaque cement affect repeated BMD measurements. METHODS: 33 patients eligible for total hip replacement were randomly assigned to either radiopaque or radiolucent cement. BMD changes up to 12 months were measured by DXA, in addition to Harris Hip Score, plain radiographs and radiostereometric analysis (RSA). RESULTS: Periprosthetic BMD declined during the first 3-6 months in all zones in both groups. The greatest reduction (14%) was seen in the proximal Gruen zones (1 and 7). We found a significant difference in Gruen zones 1 and 2, where the measured bone loss was higher in the radiolucent cement group. CONCLUSIONS: The presence of radiopaque agents in bone cement may influence DXA measurements of bone remodelling.ClinicalTrials.gov identifier NCT00473421.
Assuntos
Absorciometria de Fóton/métodos , Artroplastia de Quadril/métodos , Cimentos Ósseos , Doenças Ósseas Metabólicas/diagnóstico , Remodelação Óssea , Fêmur/diagnóstico por imagem , Prótese de Quadril , Adulto , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea , Doenças Ósseas Metabólicas/metabolismo , Feminino , Fêmur/cirurgia , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Análise RadioestereométricaRESUMO
BACKGROUND AND PURPOSE: Hydroxyapatite has been used for a long time as an adjunct to enhance cementless fixation. The benefit of this is still debated, but new methods of hydroxyapatite deposition have emerged, offering possible gains. In order to investigate this further, we compared the migration pattern and periprosthetic bone remodeling in a cementless femoral stem with either electrochemically deposited hydroxyapatite-called Bonemaster (BM)-or a conventional plasma-sprayed hydroxyapatite (HA) coating. PATIENTS AND METHODS: 55 hips were randomized to either BM or HA cementless femoral stems. Patients were followed with radiostereometry (RSA), dual-energy X-ray absorptiometry (DXA), radiographic measurements, and hip questionnaires for 5 years. RESULTS: For both stems, migration occurred mainly as subsidence and retroversion during the first 3 months. The BM group had a higher retroversion rate of 0.17° per month during this period, as compared to 0.06° per month for the HA group (p = 0.006). Thereafter, there was almost no movement in any direction for both stem types. Bone resorption occurred mainly during the first year, and subsequently decreased to a rate close to what is seen in normal ageing. The greatest total decrease occurred in Gruen zones 1 and 7, similar in the groups at 5 years. There was a slightly higher resorption rate in Gruen zone 7 from 2 to 5 years in the BM group (1.3% per year; p = 0.04), but in a magnitude that would scarcely affect stem stability or survival. INTERPRETATION: There were no clinically relevant differences between the 2 stems regarding stability or periprosthetic bone loss at 5 years. Electrochemically deposited HA does not appear to affect fixation or bone remodeling when compared to conventional plasma spraying at 5 years. Thus, at this point, Bonemaster appears to be safe.
Assuntos
Artroplastia de Quadril/métodos , Remodelação Óssea/fisiologia , Durapatita/química , Articulação do Quadril/diagnóstico por imagem , Prótese de Quadril , Desenho de Prótese , Absorciometria de Fóton/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Artroplastia de Quadril/efeitos adversos , Cimentos Ósseos/química , Densidade Óssea/fisiologia , Materiais Revestidos Biocompatíveis/química , Intervalos de Confiança , Feminino , Fêmur/cirurgia , Seguimentos , Articulação do Quadril/fisiopatologia , Articulação do Quadril/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios/métodos , Análise Radioestereométrica/métodos , Propriedades de Superfície , Fatores de Tempo , Resultado do TratamentoRESUMO
PURPOSE: Cross-linking has proven effective in reducing polyethylene wear in total hip replacements. However, increasing the amount of cross-links will impair other mechanical properties of the polyethylene. The optimal threshold of crosslinking has still not been established. This led to the development of a moderately cross-linked (5 Mrad) cemented cup in which wear and stability is yet to be determined. METHODS: A total of, 70 hips were included in this case series on the cemented Marathon® cup. Mean age of the patients was 78 years (SD 15). We measured wear and migration by radiostereometry at 3, 12 and 24 months. RESULTS: The proximal wear rate estimate between 3 to 24 months was 0.036 mm/year, and a total proximal wear estimate at 2 years of 0.11 mm (95% CI 0.09-0.14). Translations and rotations along the 3 cardinal axes were all at or below the precision limit, and less than what is believed to be predictive of later loosening, namely 0.2-1 mm for proximal migration. The cups remained stable after the initial "bedding in" that occurred during the first 3 months. CONCLUSIONS: Our results indicate that moderate cross-linking (5Mrad) yields low wear and high stability in this specific acetabular cup, comparable to other cups with higher cross-linking.