111 research outputs found
Poor accuracy of freehand cup positioning during total hip arthroplasty
Several studies have demonstrated a correlation between the acetabular cup position and the risk of dislocation, wear and range of motion after total hip arthroplasty. The present study was designed to evaluate the accuracy of the surgeon’s estimated position of the cup after freehand placement in total hip replacement. Peroperative estimated abduction and anteversion of 200 acetabular components (placed by three orthopaedic surgeons and nine residents) were compared with measured outcomes (according to Pradhan) on postoperative radiographs. Cups were placed in 49.7° (SD 6.7) of abduction and 16.0° (SD 8.1) of anteversion. Estimation of placement was 46.3° (SD 4.3) of abduction and 14.6° (SD 5.9) of anteversion. Of more interest is the fact that for the orthopaedic surgeons the mean inaccuracy of estimation was 4.1° (SD 3.9) for abduction and 5.2° (SD 4.5) for anteversion and for their residents this was respectively, 6.3° (SD 4.6) and 5.7° (SD 5.0). Significant differences were found between orthopaedic surgeons and residents for inaccuracy of estimation for abduction, not for anteversion. Body mass index, sex, (un)cemented fixation and surgical approach (anterolateral or posterolateral) were not significant factors. Based upon the inaccuracy of estimation, the group’s chance on future cup placement within Lewinnek’s safe zone (5–25° anteversion and 30–50° abduction) is 82.7 and 85.2% for anteversion and abduction separately. When both parameters are combined, the chance of accurate placement is only 70.5%. The chance of placement of the acetabular component within 5° of an intended position, for both abduction and anteversion is 21.5% this percentage decreases to just 2.9% when the tolerated error is 1°. There is a tendency to underestimate both abduction and anteversion. Orthopaedic surgeons are superior to their residents in estimating abduction of the acetabular component. The results of this study indicate that freehand placement of the acetabular component is not a reliable method
Climate related shifts in the NCP ecosystem, and consequences for future spatial planning
Een uitgebreide meetinspanning op de Noordzee, in combinatie met wiskundige en statistische modellering, laat zien dat de klimaatveranderingen in de vorm van een verandering in de overheersende windrichting, een toename van de windsnelheid, een toename van de zeewatertemperatuur, als wel als een toenemende CO2 concentratie van de atmosfeer, niet alleen leidt tot een verandering van de samenstelling van het zeewater in de vorm van bijvoorbeeld opgelost anorganisch koolstof en zuurgraad, maar ook tot een, zei het beperkte, verlaging van de productiviteit van op en in de zeebodem levende filterende organismen, die op hun beurt het voedsel zijn van bodembewonende vissen
Benneveld, Almaatsweg gemeente Coevorden
Op 31 mei 2010 heeft aan de Almaatsweg te Benneveld, gemeente Coevorden, provincie Drenthe, een inventariserend archeologisch veldonderzoek plaatsgevonden. De aanleiding voor het onderzoek is de voorgenomen bouw van een woning ten zuidoosten van Almaatsweg 11. Doel van het onderzoek is vast te stellen of er in het plangebied archeologische waarden aanwezig zijn. Het onderzoek bestaat uit een bureau- en een veldonderzoek. Bij het bureauonderzoek zijn bronnen geraadpleegd op het gebied van fysische geografie, archeologie en historische geografie. Tijdens het veldonderzoek zijn zes boringen geplaatst om archeologische indicatoren op te sporen en om de gaafheid van de bodem te bepalen. Het te bebouwen deel van het perceel is circa 0,2 hectare groot. Alleen dit deel is onderzocht. Het plangebied ligt op een zandrug en bevindt zich binnen een terrein van archeologische waarden, waar bewerkt vuursteen is gevonden uit het mesolithicum en neolithicum. In 1991 bleek de bodem hier nog redelijk intact te zijn. Tijdens het veldonderzoek bleek de bodem echter circa 80 centimeter te zijn afgegraven waardoor de C-horizont onder de bouwvoor is komen te liggen. De opgeboorde grond is gezeefd, maar er zijn geen archeologische indicatoren aangetroffen. Het advies luidt daarom geen nader archeologisch onderzoek te laten uitvoeren
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Metastatic melanoma in Florida, 1996-2010: Racial, demographic, occupational and tumor characteristics, and burden of metastasis
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Role, Extent, and Impact of Comorbidity on Prognosis and Survival in Advanced Metastatic Melanoma: A Review
Increased incidence of comorbidity in advanced metastatic melanoma (AMM) is emerging as an important factor in patient prognosis, treatment, and survival. This paper reviews the impact of comorbidities on the prognosis and survival outcomes of patients diagnosed with AMM. Our search initially yielded limited results. We then broadened our search to include breast, colorectal, and prostate cancer and covered malignancies in which screening (like melanoma) is associated with the detection of early-stage disease. Most studies showed that a higher prevalence of comorbidity was associated with more advanced cancer stage. Both treatment and survival of patients were influenced by age and the extent of comorbidity. Racial differences in survival were greatest for patients with no comorbidities and less evident at higher levels of comorbidity. Comorbid conditions showed differential effects for prognosis, treatment, and survival. Limited Information in the literature demonstrates that more research is warranted with respect to comorbidities and AMM
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Survival time distribution of advanced stage metastatic melanoma among whites and minority populations in Florida, 1996-2010
Differences in genetic profiles and environmental exposure may impact on the prognostic factors of metastatic melanoma with major implications on survival of minorities with advanced stage disease at presentation. This study determines the impact of stage at diagnosis, tumor location, grade and histologic type on overall survival time distribution among non-Hispanic Whites, Hispanic Whites and African Americans in Florida. A dataset of 80,349 Non-Hispanic Whites (NHW), African Americans (AA) and Hispanics Whites (HW) stage III and IV metastatic melanoma patients at presentation was obtained from Florida Cancer Data System (FCDS). Measures related to impact of stage at diagnosis, anatomic/primary site or tumor location, grade and histologic type on overall survival time distribution across racial groups are reported. Data were analyzed using SAS. Mean time univariate and multivariate survival statistics across races were analyzed by Kaplan-Meir Method and the nonparametric Log Rank Tests were used to test homogeneity of survival curves. Significant differences in survival time are reported among the races in primary sites, histology and stage at diagnosis, but not in terms of tumor grade; survival curve distributions were still significantly different even when adjustments were made for age, nodes, lymphatic invasion and tumor size
Prevalence of Headache in Tulp's Observationes Medicae (1641) with a Description of Cluster Headache
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