In Vivo surface wear mechanisms of femoral components of cemented total hip arthroplasties the influence of wear mechanism on clinical outcome

The appearance and mechanism of femoral stem wear was studied in 172 retrieved femoral components, of which 74 stems had been stable in vivo. Macroscopic, microscopic, and nano-level scales of examination were used. Loss of stem surface in response to micromotion (wear) was found to affect 93% of stems. However, changes were frequently difficult to see with the naked eye, and in 19% of cases they would have been missed completely without the use of light microscopy. The surface finish of the prosthesis determined the mechanism of stem wear. Matte surfaces showed typical abrasive processes that also damage the cement, releasing particulate debris from the cement and metal surfaces. This may destabilize the stem within the cement. Polished stems showed a typical fretting appearance with retention of debris on the stem surface and without significant damage to the cement. These differences in wear mechanism between matte and polished stems have significant effects on stem functio

Role of the HLA System in the Pathogenesis of Dupuytren’s Disease

Dupuytren’s disease (DD) is a familial, fibroproliferative, irreversible, and progressive disease of the palmar fascia, yet with unknown etiology. However, there is compelling evidence which has consistently suggested a genetic ethiopathogenesis given the high occurrence among the Northern European extraction, familial nature, and demonstration of concordance in twins. DD is an incurable, recurrent, and potentially debilitating disease with limited and ineffective treatments. Although a number of possible candidate genes have been investigated including matrix metalloproteinases (MMPs) and transforming growth factor-beta (TGF-β) genes, as yet, no consistent genetic biomarker has been identified for DD. The highly polymorphic human leukocyte antigen (HLA) region is an ideal biomarker target. There have been some coherent data within the literature to suggest a genotype to phenotype association between certain HLA loci and a number of fibrotic disorders such as keloid and scleroderma, markedly with class II molecules and disease pervasiveness and clinical progression. The aim of this review, therefore, was to investigate the evidence indicative of both positive and negative associations between particular HLA alleles and DD. There is a clear association with specific HLA alleles and predilection or protection to DD, though there is a pressing need for further supportive data. The most promising of links to the HLA region in terms of a definitive genetic biomarker is with the class II HLA-DR loci. This paper presents a detailed account of the immunogenetic component of DD and explores the possible mechanisms of association between specific HLA molecules and susceptibility to DD