32 research outputs found

    The Oxford Medial Unicompartmental Knee Arthroplasty: The South African Experience

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    Background; The Oxford unicompartmental knee arthroplasty (OUKA) is a successful treatment for endstage, symptomatic anteromedial osteoarthritis. This study reports the results of a cohort of consecutive cemented and cementless medial OUKAs from an independent center and aims to answer the following questions: what is the survival of OUKA in the hands of a nondesigner surgeon? Are there any differences in the survival of cementless and cemented OUKA? Are the failure modes any different with the cementless and cemented OUKA? Methods; One thousand one hundred twenty consecutive OUKAs were implanted in a single center for the recommended indications. Patients were prospectively identified and followed up. Survival was calculated with revision as the end point. Results; There were 522 cemented and 598 cementless implants. The mean follow-up was 8.3 years for cemented implants (range 0.5-17, standard deviation [SD] 2.9) and 2.7 years (range 0.5-7, SD 1.8) for cementless implants. The Oxford knee score improved from a preoperative mean of 22 (SD 8.1) to 40 (SD 7.9) at the last follow-up (P < .001). There were 59 failures requiring revision surgery, with a 5.3% cumulative revision rate. The most common reason for failure was progression of osteoarthritis in the lateral compartment, occurred in 26 cases (2.3%). The cumulative 10-year survival was 91% (95% confidence interval 87.3-95.2). Conclusion; The results of this prospective, consecutive case series from the African continent demonstrated that excellent results are achievable with the OUKA in independent centers if the correct indications and surgical technique are used

    Selection on age of female reproduction in the marula fruit fly, Ceratitis cosyra (Walker) (Diptera: Tephritidae), decreases total antioxidant capacity and lipid peroxidation

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Data availability: Data are available from the University of Pretoria online repository: https://doi.org/10.25403/UPresearchdata.12480569.v1The oxidative damage caused to cells by Reactive Oxygen Species (ROS) is one of several factors implicated in causing ageing. Oxidative damage may also be a proximate cost of reproductive effort that mediates the trade-off often observed between reproduction and survival. However, how the balance between oxidative damage and antioxidant protection affects life-history strategies is not fully understood. To improve our understanding, we selected on female reproductive age in the marula fruit fly, Ceratitis cosyra, and quantified the impact of selection on female and male mortality risk, female fecundity, male sperm transfer, calling and mating. Against expectations, upward-selected lines lived shorter lives and experienced some reductions in reproductive performance. Selection affected oxidative damage to lipids and total antioxidant protection, but not in the direction predicted; longer lives were associated with elevated oxidative damage, arguing against the idea that accumulated oxidative damage reduces lifespan. Greater reproductive effort was also associated with elevated oxidative damage, suggesting that oxidative damage may be a cost of reproduction, although one that did not affect survival. Our results add to a body of data showing that the relationship between lifespan, reproduction and oxidative damage is more complex than predicted by existing theories.NRF University of Pretori

    The Knee Osteoarthritis Grading System for Arthroplasty

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    Background: The aim of this study is to validate the Knee Osteoarthritis Grading System (KOGS) of progressive osteoarthritic degeneration for the tri-compartmental knee. This system defines the site and severity of osteoarthritis to determine a specific knee arthroplasty. Methods: The radiographic sequence for KOGS includes standing coronal (anteroposterior), lateral, 30° skyline patella, 15° and 45° Rosenberg and stress views in 20° of flexion. Cohen's kappa and related agreement statistical methods were used to assess the level of concordance of the 7 evaluators between A and B cohorts for each evaluator and also against the actual arthroplasty used. Sensitivity and specificity was also assessed for the KOGS in identifying true partial knee arthroplasties (PKAs) and total knee arthroplasties (TKAs) as decided from the cohort A evaluations. Results: From a cohort of 330 patients who were included in the study, 71 (22.5%) underwent a TKA procedure, 258 (78.2%) a PKA, and 1 (0.3%) was neither a TKA nor PKA. KOGS was able to identify true PKAs (sensitivity) in the range of 92.2%-98.5% across all the different evaluators. The KOGS method was able to identify a PKA or a TKA with an accuracy ranging from 92% to 98.8% across all different evaluators. The surgical results after 20 months are at least comparable with the expected average in the academic literature. Conclusion: The KOGS classification provides a reliable and accurate tool to assess suitability of an individual patient for undergoing PKA or TKA

    Radiological Decision Aid to determine suitability for medial unicompartmental knee arthroplasty: development and preliminary validation

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    Aims: An evidence-based radiographic Decision Aid for meniscal-bearing unicompartmental knee arthroplasty (UKA) has been developed and this study investigates its performance at an independent centre. Patients: and Methods Pre-operative radiographs, including stress views, from a consecutive cohort of 550 knees undergoing arthroplasty (UKA or total knee arthroplasty; TKA) by a single-surgeon were assessed. Suitability for UKA was determined using the Decision Aid, with the assessor blinded to treatment received, and compared with actual treatment received, which was determined by an experienced UKA surgeon based on history, examination, radiographic assessment including stress radiographs, and intra-operative assessment in line with the recommended indications as described in the literature. Results: The sensitivity and specificity of the Decision Aid was 92% and 88%, respectively. Excluding knees where a clear pre-operative plan was made to perform TKA, i.e. patient request, the sensitivity was 93% and specificity 96%. The false-positive rate was low (2.4%) with all affected patients readily identifiable during joint inspection at surgery. In patients meeting Decision Aid criteria and receiving UKA, the five-year survival was 99% (95% confidence intervals (CI) 97 to 100). The false negatives (3.5%), who received UKA but did not meet the criteria, had significantly worse functional outcomes (flexion p < 0.001, American Knee Society Score - Functional p < 0.001, University of California Los Angeles score p = 0.04), and lower implant survival of 93.1% (95% CI 77.6 to 100). Conclusion: The radiographic Decision Aid safely and reliably identifies appropriate patients for meniscal-bearing UKA and achieves good results in this population. The widespread use of the Decision Aid should improve the results of UKA

    Satellite Tagging and Biopsy Sampling of Killer Whales at Subantarctic Marion Island: Effectiveness, Immediate Reactions and Long-Term Responses

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    Remote tissue biopsy sampling and satellite tagging are becoming widely used in large marine vertebrate studies because they allow the collection of a diverse suite of otherwise difficult-to-obtain data which are critical in understanding the ecology of these species and to their conservation and management. Researchers must carefully consider their methods not only from an animal welfare perspective, but also to ensure the scientific rigour and validity of their results. We report methods for shore-based, remote biopsy sampling and satellite tagging of killer whales Orcinus orca at Subantarctic Marion Island. The performance of these methods is critically assessed using 1) the attachment duration of low-impact minimally percutaneous satellite tags; 2) the immediate behavioural reactions of animals to biopsy sampling and satellite tagging; 3) the effect of researcher experience on biopsy sampling and satellite tagging; and 4) the mid- (1 month) and long- (24 month) term behavioural consequences. To study mid- and long-term behavioural changes we used multievent capture-recapture models that accommodate imperfect detection and individual heterogeneity. We made 72 biopsy sampling attempts (resulting in 32 tissue samples) and 37 satellite tagging attempts (deploying 19 tags). Biopsy sampling success rates were low (43%), but tagging rates were high with improved tag designs (86%). The improved tags remained attached for 26±14 days (mean ± SD). Individuals most often showed no reaction when attempts missed (66%) and a slight reaction-defined as a slight flinch, slight shake, short acceleration, or immediate dive-when hit (54%). Severe immediate reactions were never observed. Hit or miss and age-sex class were important predictors of the reaction, but the method (tag or biopsy) was unimportant. Multievent trap-dependence modelling revealed considerable variation in individual sighting patterns; however, there were no significant mid- or long-term changes following biopsy sampling or tagging

    Current Data on and Clinical Insights into the Treatment of First Episode Nonaffective Psychosis: A Comprehensive Review

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    Implementing the most suitable treatment strategies and making appropriate clinical decisions about individuals with a first episode of psychosis (FEP) is a complex and crucial task, with relevant impact in illness outcome. Treatment approaches in the early stages should go beyond choosing the right antipsychotic drug and should also address tractable factors influencing the risk of relapse. Effectiveness and likely metabolic and endocrine disturbances differ among second-generation antipsychotics (SGAs) and should guide the choice of the first-line treatment. Clinicians should be aware of the high risk of cardiovascular morbidity and mortality in schizophrenia patients, and therefore monitoring weight and metabolic changes across time is mandatory. Behavioral and counseling interventions might be partly effective in reducing weight gain and metabolic disturbances. Ziprasidone and aripiprazole have been described to be least commonly associated with weight gain or metabolic changes. In addition, some of the SGAs (risperidone, amisulpride, and paliperidone) have been associated with a significant increase of plasma prolactin levels. Overall, in cases of FEP, there should be a clear recommendation of using lower doses of the antipsychotic medication. If no or minimal clinical improvement is found after 2 weeks of treatment, such patients may benefit from a change or augmentation of treatment. Clinicians should provide accurate information to patients and relatives about the high risk of relapse if antipsychotics are discontinued, even if patients have been symptom free and functionally recovered on antipsychotic treatment for a lengthy period of time.This review was carried out at the Hospital Marque´s de Valdecilla, University of Cantabria, Santander, Spain, with the following Grant support: Instituto de Salud Carlos III PI020499, PI050427, PI060507, Plan Nacional de Drugs Research Grant 2005-Orden sco/3246/2004, SENY Fundacio´ Research Grant CI 2005-0308007, Fundacio´n Marque´s de Valdecilla API07/011 and CIBERSAM

    The development and validation of a radiological Decision Aid to determine suitability for medial unicompartmental knee replacement

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    Aims An evidence based radiographic Decision Aid for meniscal-bearing unicompartmental knee replacement (UKR) has been developed and this study investigates its performance at an independent centre. Patients and Methods Pre-operative radiographs, including stress views, from a consecutive cohort of 550 knees undergoing replacement (UKR or TKR) by a single-surgeon were assessed. Suitability for UKR was determined using the Decision Aid with the assessor blinded to treatment received. Results The sensitivity and specificity of the Decision Aid was 92% and 88% respectively. Excluding knees where a clear pre-operative plan was made to perform TKR, i.e. patient request, the sensitivity was 93% and specificity 96%. The false-positive rate was low (2.3%) with all readily identifiable during joint inspection at surgery. In patients meeting Decision Aid criteria and receiving UKR the 5-year survival was 99% (95%CI 97 to 100%). The false-negatives (3.3%), who received UKR, but did not meet criteria, had significantly worse functional outcomes (flexion (p&lt;0.001), AKSS-Functional (p&lt;0.001), UCLA (p=0.04)), and lower implant survival 93.1% (95%CI 77.6 – 100%). Conclusion The radiographic Decision Aid safely and reliably identifies appropriate patients for meniscal-bearing UKR and achieves good results in this population. The widespread use of the Decision Aid should improve the results of UKR.</p

    The Knee Osteoarthritis Grading System (KOGS) for arthroplasty

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    Background The aim of this study is to validate the Knee Osteoarthritis Grading system (KOGS) of progressive osteoarthritic (OA) degeneration for the Tri-compartmental knee. This system defines the site and severity of OA to determine a specific knee replacement. Methods The radiographic sequence for KOGS includes standing coronal (antero-posterior), lateral, 30° skyline patella, 15° and 45° Rosenberg and stress views in 20° of flexion. Cohen’s Kappa and related agreement statistical methods were used to assess the level of concordance of the seven evaluators between A and B cohorts for each evaluator and also against the actual arthroplasty used. Sensitivity and specificity was also assessed for the KOGS in identifying true partial knee replacements (PKR) and total knee replacements (TKR) as decided from the cohort A evaluations. Results From a cohort of 330 patients who were included in the study, 71 (22.5%) underwent a TKR procedure, 258 (78.2%) a PKR and 1 (0.3%) was neither a TKR nor PKR. KOGS was able to identify true PKRs (sensitivity) in the range of 92.2% to 98.5% across all the different evaluators. The KOGS method was able to identify a PKR or a TKR with an accuracy ranging from 92% to 98.8% across all different evaluators. The surgical results after 20 months are at least comparable with the expected average in the academic literature. Conclusion The KOGS classification provides a reliable and accurate tool to assess suitability of an individual patient for undergoing partial or total knee replacement
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