16 research outputs found
Surface pretreatment for prolonged survival of cemented tibial prosthesis components: full- vs. surface-cementation technique
BACKGROUND: One of few persisting problems of cemented total knee arthroplasty (TKA) is aseptic loosening of tibial component due to degradation of the interface between bone cement and metallic tibial shaft component, particularly for surface cemented tibial components. Surface cementation technique has important clinical meaning in case of revision and for avoidance of stress shielding. Degradation of the interface between bone cement and bone may be a secondary effect due to excessive crack formation in bone cement starting at the opposite metallic surface. METHODS: This study was done to prove crack formation in the bone cement near the metallic surface when this is not coated. We propose a newly developed coating process by PVD layering with SiO(x )to avoid that crack formation in the bone cement. A biomechanical model for vibration fatigue test was done to simulate the physiological and biomechanical conditions of the human knee joint and to prove excessive crack formation. RESULTS: It was found that coated tibial components showed a highly significant reduction of cement cracking near the interface metal/bone cement (p < 0.01) and a significant reduction of gap formation in the interface metal-to-bone cement (p < 0.05). CONCLUSION: Coating dramatically reduces hydrolytic- and stress-related crack formation at the prosthesis interface metal/bone cement. This leads to a more homogenous load transfer into the cement mantle which should reduce the frequency of loosening in the interfaces metal/bone cement/bone. With surface coating of the tibial component it should become possible that surface cemented TKAs reveal similar loosening rates as TKAs both surface and stem cemented. This would be an important clinical advantage since it is believed that surface cementing reduces metaphyseal bone loss in case of revision and stress shielding for better bone health
Cost-effectiveness of an integrated 'fast track' rehabilitation service for multi-trauma patients involving dedicated early rehabilitation intervention programs: design of a prospective, multi-centre, non-randomised clinical trial
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79649.pdf (publisher's version ) (Open Access)ABSTRACT: BACKGROUND: In conventional multi-trauma care service (CTCS), patients are admitted to hospital via the accident & emergency room. After surgery they are transferred to the IC-unit followed by the general surgery ward. Ensuing treatment takes place in a hospital's outpatient clinic, a rehabilitation centre, a nursing home or the community. Typically, each of the CTCS partners may have its own more or less autonomous treatment perspective. Clinical evidence, however, suggests that an integrated multi-trauma rehabilitation approach ('Supported Fast-track multi-Trauma Rehabilitation Service': SFTRS), featuring: 1) earlier transfer to a specialised trauma rehabilitation unit; 2) earlier start of 'non-weight-bearing' training and multidisciplinary treatment; 3) well-documented treatment protocols; 4) early individual goal-setting; 5) co-ordination of treatment between trauma surgeon and physiatrist, and 6) shorter lengths-of-stay, may be more (cost-)effective.This paper describes the design of a prospective cohort study evaluating the (cost-) effectiveness of SFTRS relative to CTCS. METHODS/DESIGN: The study population includes multi-trauma patients, admitted to one of the participating hospitals, with an Injury Severity Scale score > = 16, complex multiple injuries in several extremities or complex pelvic and/or acetabulum fractures. In a prospective cohort study CTCS and SFTRS will be contrasted. The inclusion period is 19 months. The duration of follow-up is 12 months, with measurements taken at baseline, and at 3,6,9 and 12 months post-injury.Primary outcome measures are 'quality of life' (SF-36) and 'functional health status' (Functional Independence Measure). Secondary outcome measures are the Hospital Anxiety & Depression Scale, the Mini-Mental State Examination as an indicator of cognitive functioning, and the Canadian Occupational Performance Measure measuring the extent to which individual ADL treatment goals are met. Costs will be assessed using the PROductivity and DISease Questionnaire and a cost questionnaire. DISCUSSION: The study will yield results on the efficiency of an adapted care service for multi-trauma patients (SFTRS) featuring earlier (and condensed) involvement of specialised rehabilitation treatment. Results will show whether improved SFTRS logistics, combined with shorter stays in hospital and rehabilitation clinic and specialised early rehabilitation training modules are more (cost-) effective, relative to CTCS. TRIAL REGISTRATION: Current Controlled Trials register (ISRCTN68246661) and Netherlands Trial Register (NTR139)
Eine differenzierte Bewertung "Schwerverletzter" zur effizienten Dokumentation von kritischen Unfallschwerpunkten im StraĂźenverkehr
Die instabile pertrochantäre Femurfraktur. Komplikationen, Frakturdynamik und Outcome nach extra- und intramedullärer Versorgung - Vergleich zwischen PCCP(TM), PFN und PFNA
Implications of the center of rotation concept for the reconstruction of anterior column lordosis and axial preloads in spinal deformity surgery
eine fMRI-Fallstudie bei zwei Patienten nach schwerer Unfalltraumatisierung
Neuroimaging research on the neurobiology of chronic PTSD (posttraumatic stress disorder) has revealed structural and functional alterations primarily affecting areas of the medial temporal lobe (hippocampus, amygdala, and parahippocampal gyrus) and the frontal cortex known to be associated with the disorder. Using functional magnetic resonance imaging (fMRI), the present study studied the functional neuroanatomy of traumatic and non-traumatic emotional memory in two surgical patients who had sustained severe accident trauma. While patient 1 had developed acute PTSD following the traumatic event, patient 2 (control) did not. When confronted with traumatic (relative to negatively valenced non-traumatic) memory, the PTSD patient exhibited evidence for increased neural activity in the right and the left superior temporal lobe, the amygdala, the left angular gyrus, and the medial frontal gyrus, while the non-PTSD patient exposed to identical conditions showed increased activations in frontal and parietal regions. Both patients exhibited identical activation patterns when recalling non-traumatic memories relative to neutral memories. It is concluded that the pronounced activation patterns in the PTSD patient may be considered specific for acute PTSD, involved with the emotional arousal and the vivid visual recollections typical for the acute phase of the disorder.Neuere bildgebende Studien zur Neurobiologie der chronifizierten PTSD lassen vermuten, dass das Störungsbild sowohl mit funktionellen als auch strukturellen Veränderungen in umschriebenen Hirnregionen des medialen Temporallappens (Hippokampus, Amygdala, Parahippokampaler Gyrus) und des frontalen Cortex einhergeht. Die vorliegende fMRT(funktionelle Magnetresonanztomografie)-Studie untersuchte die funktionelle Neuroanatomie traumatischer und nicht-traumatischer Erinnerungen bei zwei chirurgischen Patienten nach schwerer Unfalltraumatisierung. Nur Patient 1 entwickelte eine akute PTSD, während Patient 2 ohne klinisch relevante PTSD-Symptomatik blieb. Konfrontiert mit der Unfallerinnerung (im Vergleich zu negativen, aber nicht traumatischen Erinnerungen) zeigte der PTSD-Patient vermehrte neuronale Aktivitäten im Bereich des rechten und linken superioren Temporallappens, im Bereich der Amygdalae, des linken Gyrus angularis, und des Gyrus frontalis medialis. Der Patient ohne PTSD-Symptome zeigte bei gleichen Untersuchungsbedingungen vermehrte neuronale Aktivitäten in frontalen und parietalen Regionen. Beide Patienten zeigten identische Aktivierungsmuster für den Vergleich negativer, nicht-traumatischer zu neutralen Erinnerungen. Die Untersuchungsergebnisse lassen vermuten, dass die besonderen Aktivierungsmuster bei dem Patienten mit akuter PTSD spezifisch für das Stadium einer akuten PTSD sind, die typischerweise durch sehr lebendige und emotional belastende Wiedererinnerungen der traumatischen Situation charakterisiert ist
Hydrolytic stability of composite repair bond
The hydrolytic stability of composite repairs is a desirable property. In the present study, the composite repair microtensile bond strength, failure mode distribution, and nanoleakage occurrence before and after thermocycling were evaluated. Standardized, 1-month-old composite substrates were roughened, cleaned, and randomly assigned to seven groups according to the intermediate agent applied. Resin-based, silane-based, and combined silane/adhesive coupling agents were investigated. The same resin composite as the substrate was used for repair. For each group, repaired samples were wet stored for 24 h (37 degrees C) or thermocycled (5,000 cycles, 5-55 degrees C). Failure mode and silver nitrate penetration were examined by stereomicroscopy. Intermediate agent, experimental condition, and their interaction were significant factors. Hydrophobic flowable composites resulted in statistically higher repair strengths, lower occurrence of adhesive failures, and good quality interfacial coupling without any silver uptake in both conditions. Light-curing, hydrophilic resin monomer-based intermediate agents, although not affected by thermocycling, showed a more pronounced silver penetration. The composite repair strength of a self-curing silane/adhesive agent was significantly affected by thermal stresses, despite the absence of silver uptake. A prehydrolized silane agent recorded the lowest repair strength, with minimal or no evidence of interfacial silver impregnation after thermocycling. In conclusion, flowability and hydrophobic nature can be considered important properties when selecting intermediate agents for composite repair