45 research outputs found

    Improvements in survival of the uncemented Nottingham Total Shoulder prosthesis: a prospective comparative study

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    <p>Abstract</p> <p>Background</p> <p>The uncemented Nottingham Total Shoulder Replacement prosthesis system (Nottingham TSR) was developed from the previous BioModular<sup>® </sup>shoulder prosthesis taking into consideration the causes of the initial implant's failure.</p> <p>We investigated the impact of changes in the design of Nottingham TSR prosthesis on its survivorship rate.</p> <p>Methods</p> <p>Survivorship analyses of three types of uncemented total shoulder arthroplasty prostheses (BioModular<sup>®</sup>, initial Nottingham TSR and current Nottingham TSR systems with 11, 8 and 4 year survivorship data respectively) were compared. All these prostheses were implanted for the treatment of disabling pain in the shoulder due to primary and secondary osteoarthritis or rheumatoid arthritis. Each type of the prosthesis studied was implanted in consecutive group of patients – 90 patients with BioModular<sup>® </sup>system, 103 with the initial Nottingham TSR and 34 patients with the current Nottingham TSR system.</p> <p>The comparison of the annual cumulative survivorship values in the compatible time range between the three groups was done according to the paired <it>t </it>test.</p> <p>Results</p> <p>The 8-year and 11-year survivorship rates for the initially used modified BioModular<sup>® </sup>uncemented prosthesis were relatively low (75.6% and 71.7% respectively) comparing to the reported survivorship of the conventional cemented implants. The 8-year survivorship for the uncemented Nottingham TSR prosthesis was significantly higher (81.8%), but still not in the desired range of above 90%, that is found in other cemented designs. Glenoid component loosening was the main factor of prosthesis failure in both prostheses and mainly occurred in the first 4 postoperative years. The 4-year survivorship of the currently re-designed Nottingham TSR prosthesis, with hydroxylapatite coating of the glenoid baseplate, was significantly higher, 93.1% as compared to 85.1% of the previous Nottingham TSR.</p> <p>Conclusion</p> <p>The initial Nottingham shoulder prosthesis showed significantly higher survivorship than the BioModular<sup>® </sup>uncemented prosthesis, but lower than expected. Subsequently re-designed Nottingham TSR system presented a high short term survivorship rate that encourages its ongoing use</p

    A novel method to compare protein structures using local descriptors

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    <p>Abstract</p> <p>Background</p> <p>Protein structure comparison is one of the most widely performed tasks in bioinformatics. However, currently used methods have problems with the so-called "difficult similarities", including considerable shifts and distortions of structure, sequential swaps and circular permutations. There is a demand for efficient and automated systems capable of overcoming these difficulties, which may lead to the discovery of previously unknown structural relationships.</p> <p>Results</p> <p>We present a novel method for protein structure comparison based on the formalism of local descriptors of protein structure - DEscriptor Defined Alignment (DEDAL). Local similarities identified by pairs of similar descriptors are extended into global structural alignments. We demonstrate the method's capability by aligning structures in difficult benchmark sets: curated alignments in the SISYPHUS database, as well as SISY and RIPC sets, including non-sequential and non-rigid-body alignments. On the most difficult RIPC set of sequence alignment pairs the method achieves an accuracy of 77% (the second best method tested achieves 60% accuracy).</p> <p>Conclusions</p> <p>DEDAL is fast enough to be used in whole proteome applications, and by lowering the threshold of detectable structure similarity it may shed additional light on molecular evolution processes. It is well suited to improving automatic classification of structure domains, helping analyze protein fold space, or to improving protein classification schemes. DEDAL is available online at <url>http://bioexploratorium.pl/EP/DEDAL</url>.</p

    Like mother, like child : investigating perinatal and maternal health stress in post-medieval London.

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    Post-Medieval London (sixteenth-nineteenth centuries) was a stressful environment for the poor. Overcrowded and squalid housing, physically demanding and risky working conditions, air and water pollution, inadequate diet and exposure to infectious diseases created high levels of morbidity and low life expectancy. All of these factors pressed with particular severity on the lowest members of the social strata, with burgeoning disparities in health between the richest and poorest. Foetal, perinatal and infant skeletal remains provide the most sensitive source of bioarchaeological information regarding past population health and in particular maternal well-being. This chapter examined the evidence for chronic growth and health disruption in 136 foetal, perinatal and infant skeletons from four low-status cemetery samples in post-medieval London. The aim of this study was to consider the impact of poverty on the maternal-infant nexus, through an analysis of evidence of growth disruption and pathological lesions. The results highlight the dire consequences of poverty in London during this period from the very earliest moments of life

    Posterior Malleolar Ankle Fractures

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    Category: Ankle Introduction/Purpose: There is an increasing acceptance that the clinical outcomes following posterior malleolar fractures are less than satisfactory. In creating a treatment guiding classification and algorithm, we report our results in a system change in management of posterior malleolar fractures in our unit. Methods: All fractures were classified according to Mason and Molloy classification (Foot Ankle Int. 2017 Nov;38(11):1229-1235) based on CT scans obtained pre-operatively. This dictated the treatment algorithm. Type 1 fractures underwent syndesmotic fixation. Type 2A fractures underwent ORIF through a posterolateral incision, and type 2B and 3 fractures underwent ORIF through a posteromedial incision. The patient remained NWB for 6 weeks postoperative. Data was collected prospectively from December 2014 to July 2017. Results: Patient-related outcome measures were obtained in 50 patients with at least 1 year follow up (mean 18 months). The overall OMAS score for all posterior malleolar fractures in this cohort was 74.1 (range 35-100). According to Mason and Molloy classification, the mean OMAS for type 1 was 75.9 (Range 30-100), type 2A 75.0 (range 35-100), type 2B 74.0 (range 55-100) and type 3 70.5 (Range 35-100). Using one way ANOVA test, there was no significant difference (p=.886) between groups or within groups. There was a trend, however, that the lower the Mason and Molloy classification had higher OMAS outcomes. The overall 1-year EQ-5D index for this cohort was 0.88 (SD 0.22). The average visual analogue score for this patient group was 77.5 (SD 26.2). Conclusion: We have been able to demonstrate an improvement in functional scores for all posterior malleolar fractures with the treatment algorithm applied using the Mason and Molloy classification. This is compared to our previous study where traditional posterior malleolar management was undertaken. Our OMAS scores have now improved to what would be expected from unimalleolar fractures, illustrating the importance of understanding the injury mechanism and patterns of injury. Mason and Molloy type 3 fractures have marginally poorer outcomes, which correlates with a more significant injury
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