Neste trabalho propõe-se o projeto e a análise estrutural de uma haste femoral de implante de quadril em material compósito polimérico. No trabalho, realizaram-se algumas etapas com a finalidade de obter parâmetros confiáveis de comportamento do material, visando à consistência dos resultados numéricos e experimentais. Primeiramente, faz-se um levantamento bibliográfico sobre o comportamento mecânico dos materiais compósitos poliméricos reforçados, como também dos critérios de falha existentes para este tipo de material. Em seguida, apresentam-se as etapas experimentais com a descrição dos procedimentos de fabricação dos corpos-de-prova e os resultados obtidos a partir dos ensaios quase-estáticos de tração do poliuretano derivado de óleo de mamona. A etapa seguinte foi desenvolver um dispositivo de ensaio monotônico quase-estático para a haste femoral em poliuretano com o objetivo de levantar a curva força-deslocamento seguindo as especificações das normas ISO 7206-3 e ISO 7206-4. Com base nos resultados experimentais obtidos, foi possível propor um reforço estrutural, na forma de tubo, na haste femoral em poliuretano e adotar uma análise de falha progressiva para determinar o seu comportamento mecânico. Para esta finalidade foi implementado um modelo de material em sub-rotina FORTRAN, compilada em conjunto com um programa de elementos finitos (ABAQUS). Concluiu-se, que o modelo de material implementado e o reforço estrutural proposto para a haste femoral traz contribuições inovadoras, visto que se pode prever com mais precisão o comportamento mecânico da haste femoral reforçada com o tubo em material compósito polimérico. / A design and structural analysis of a femoral stem using a polymeric composite material is proposed in this work. The work had some steps in order to achieve trusty parameters for the material behavior aiming the consistence of numerical and experimental results. In the first step, a bibliographic review of mechanical behavior of reinforced polymeric composite materials as well as failure criterion was done. Following experimental steps are presented with specimen manufacturing procedure description and the results obtained from quasi-statics tension tests of polyurethane derivated from castor oil. The next step was the development of a monotonic quasistatic test device for the polyurethane femoral stem aiming to determine the forcedisplacement curve according to ISO 7206-3 and ISO 7206-4 standards. Considering the experimental results obtained it was possible to propose a structural reinforcement, which consists on a tube, in the polyurethane femoral stem and to adopt a progressive failure analysis in order to determine its mechanical behavior. A material model using FORTRAN sub-routine was developed and compiled joint with a finite element program (ABAQUS). The conclusion is that the model developed and the structural proposed reinforcement for the femoral stem bring innovation for this contribution once it is possible to preview accurately the mechanical behavior of the reinforced femoral stem with tube in polymeric composite material.

O domínio da técnica de microanastomose vascular é um pré-requisito essencial para a realização de procedimentos microcirúrgicos reconstrutivos, como reimplantes e transferência livre de tecidos. Até hoje, a técnica de sutura convencional é a mais aceita na prática clínica, por sua segurança e versatilidade. Apesar disso, ela apresenta alguns problemas por ser tecnicamente difícil, consumir tempo considerável e causar traumatismo adicional à parede do vaso. O objetivo deste estudo, foi testar um método alternativo de microanastomose arterial, reduzindo o número de pontos de sutura com aplicação do adesivo de fibrina. Sessenta ratos da raça Wistar foram submetidos a microanastomose vascular nas artérias femorais ou carótidas. Os animais foram divididos em quatro subgrupos de acordo com a artéria operada e a técnica de sutura empregada: FSC (femoral - sutura convencional), FAF (femoral - sutura mínima com adesivo de fibrina), CSC (carótida - sutura convencional) e CAF (carótida - sutura mínima com adesivo de fibrina). As duas técnicas de anastomose foram comparadas através de análise estatística dos parâmetros clínicos e histopatológicos. A média de pontos de sutura por anastomose nos subgrupos FSC e CSC foi de 7,7 e 9,5, respectivamente. No subgrupo FAF, as anastomoses foram realizadas com apenas quatro pontos de sutura e no subgrupo CAF, com apenas seis. O tempo de anastomose foi, em média: 15,81 minutos no subgrupo FSC, 13,62 minutos no subgrupo FAF, 18,87 minutos no subgrupo CSC e 17,33 minutos no subgrupo CAF. A aplicação do adesivo de fibrina reduziu, significativamente, o número de pontos e o tempo necessário para realização das anastomoses, nos subgrupos FAF e CAF. A intensidade do sangramento anastomótico também foi reduzida de maneira significativa nestes subgrupos. A freqüência da permeabilidade imediata e tardia foi de 100% em todos os subgrupos, exceto no subgrupo FAF, onde a permeabilidade tardia foi de 93,33%. Não foram observadas diferenças significativas entre as duas técnicas, em relação aos parâmetros histopatológicos avaliados (processo inflamatório, fibrose da camada média e hiperplasia subintimal). O autor concluiu que a técnica de sutura mínima com aplicação do adesivo de fibrina foi mais fácil e rápida que a técnica de sutura convencional, sem aumento da trombogenicidade das anastomoses, no modelo experimental utilizado. / Mastering of the microvascular anastomosis technique is an essencial requirement to perform reconstructive microsurgical procedures, such as replantation surgery and free tissue transfers. Until now, the conventional suture technique is the most widely accepted in the clinical setting, for its safety and versatility. However, this technique presents some problems for being technically difficult, time consuming and causes additional trauma to the vessel wall. The aim of this study was to test an alternative method of microvascular arterial anastomosis, by reducing the number of sutures with application of fibrin adhesive. Sixty Wistar rats underwent to microvascular anastomosis at the femoral or carotid arteries. The animals were divided into four subgroups, according to the operated artery and the employed suture technique: FCS (femoral - conventional suture), FFA (femoral - minimal suture with fibrin adhesive), CCS (carotid - conventional suture) and CFA (carotid - minimal suture with fibrin adhesive). Both anastomosis techniques were compared by means of statistical analisys of the clinical and histopathological parameters. The mean number of sutures required to complete the anastomosis was 7,7 in subgroup FCS and 9,5 in subgroup CCS. In subgroup FFA, the anastomosis was performed with only four sutures and in subgroup CFA, with only six. The mean anastomotic time was 15,81 minutes in subgroup FCS, 13,62 minutes in subgroup FFA, 18,87 minutes in subgroup CCS and 17,33 minutes in subgroup CCS. The application of fibrin adhesive, significantly reduced the number of sutures and the time taken to perform the anastomosis, in subgroups FFA and CFA. The amount of anastomotic bleeding was also significantly reduced in these subgroups. The immediate and late patency rates were 100% in all subgroups, except in subgroup FFA where it was 93,33%. No significant differences were observed among the two techniques, concerning the evaluated histopathological parameters (inflammatory process, medial fibrosis and subintimal hyperplasia). The author concluded that, the fibrin adhesive application with minimal suture technique was faster and easier than the conventional suture technique, without increasing the trombogenicity of the anastomosis, in this experimental model.

Neste trabalho propõe-se o projeto e a análise estrutural de uma haste femoral de implante de quadril em material compósito polimérico. No trabalho, realizaram-se algumas etapas com a finalidade de obter parâmetros confiáveis de comportamento do material, visando à consistência dos resultados numéricos e experimentais. Primeiramente, faz-se um levantamento bibliográfico sobre o comportamento mecânico dos materiais compósitos poliméricos reforçados, como também dos critérios de falha existentes para este tipo de material. Em seguida, apresentam-se as etapas experimentais com a descrição dos procedimentos de fabricação dos corpos-de-prova e os resultados obtidos a partir dos ensaios quase-estáticos de tração do poliuretano derivado de óleo de mamona. A etapa seguinte foi desenvolver um dispositivo de ensaio monotônico quase-estático para a haste femoral em poliuretano com o objetivo de levantar a curva força-deslocamento seguindo as especificações das normas ISO 7206-3 e ISO 7206-4. Com base nos resultados experimentais obtidos, foi possível propor um reforço estrutural, na forma de tubo, na haste femoral em poliuretano e adotar uma análise de falha progressiva para determinar o seu comportamento mecânico. Para esta finalidade foi implementado um modelo de material em sub-rotina FORTRAN, compilada em conjunto com um programa de elementos finitos (ABAQUS). Concluiu-se, que o modelo de material implementado e o reforço estrutural proposto para a haste femoral traz contribuições inovadoras, visto que se pode prever com mais precisão o comportamento mecânico da haste femoral reforçada com o tubo em material compósito polimérico. / A design and structural analysis of a femoral stem using a polymeric composite material is proposed in this work. The work had some steps in order to achieve trusty parameters for the material behavior aiming the consistence of numerical and experimental results. In the first step, a bibliographic review of mechanical behavior of reinforced polymeric composite materials as well as failure criterion was done. Following experimental steps are presented with specimen manufacturing procedure description and the results obtained from quasi-statics tension tests of polyurethane derivated from castor oil. The next step was the development of a monotonic quasistatic test device for the polyurethane femoral stem aiming to determine the forcedisplacement curve according to ISO 7206-3 and ISO 7206-4 standards. Considering the experimental results obtained it was possible to propose a structural reinforcement, which consists on a tube, in the polyurethane femoral stem and to adopt a progressive failure analysis in order to determine its mechanical behavior. A material model using FORTRAN sub-routine was developed and compiled joint with a finite element program (ABAQUS). The conclusion is that the model developed and the structural proposed reinforcement for the femoral stem bring innovation for this contribution once it is possible to preview accurately the mechanical behavior of the reinforced femoral stem with tube in polymeric composite material.

A presente tese investigou o efeito da ingestão de cafeína no desempenho no ciclismo, no recrutamento muscular, na contribuição energética, no lactato sanguíneo, nas respostas fisiológicas e perceptivas e no desenvolvimento de fadiga central e periférica em diferentes modelos de exercício aeróbio de alta intensidade. Nove ciclistas do sexo masculino (32,3 ± 6,0 anos de idade, 79,3 ± 6,8 kg, 181,2 ± 7,9 cm e VO2máx 55,2 ± 5,7 mL.kg-1.min-1) completaram 11 sessões experimentais. Os participantes foram submetidos a testes contrarrelógio de 4.000 m, testes com carga constante até a exaustão realizados na potência média do contrarrelógio (313 ± 41 W e 100 ± 10 rpm), e ainda testes com carga constante com tempo fixo correspondente a 60% do tempo sustentado no teste de carga constante até a exaustão (237,2 ± 56,0 s). Os participantes ingeriram cápsulas contendo placebo ou cafeína (5 mg.kg-1 de massa corporal) 60 minutos antes da realização dos testes, em ordem contrabalançada e em um modelo duplo-cego. Respostas cardiorrespiratórias e perceptivas foram mensuradas durante os testes. Lactato sanguíneo foi coletado antes e após o exercício. Avaliações neuromusculares foram realizadas através de estimulação elétrica no nervo femoral nos momentos Baseline (previamente à ingestão da cápsula), Pré-EX (uma hora após a ingestão, antes do exercício), e Pós-EX (2 min após o exercício). A ingestão de 5 mg.kg-1 de cafeína melhorou o desempenho no teste contrarrelógio de 4.000 m de ciclismo (-6,9 ± 7,4 s; p = 0,024), devido a um aumento na contribuição anaeróbia. O desempenho no teste com carga constante até a exaustão também foi melhor após a ingestão de cafeína (+134,3 ± 81,5 s; p = 0,001), mas neste caso acompanhado por maior contribuição aeróbia. A ingestão de cafeína previamente a realização do exercício proporcionou efeito ergogênico no teste contrarrelógio de 4.000 m e no teste de carga constante até a exaustão, sem alterar o limiar de fadiga periférica. Entre os componentes periféricos avaliados, a taxa máxima de desenvolvimento de força reduziu significativamente menos após o teste de carga constante até a exaustão na condição cafeína, mesmo como o tempo de exercício prolongado, e também reduziu significativamente menos após o teste de carga constante e tempo fixo, o que sugere que a cafeína pode ter alterado o processo acoplamento excitação-contração, o que resultou em atraso da fadiga periférica. Além disso, no teste com carga constante até a exaustão, a disposição e a sensação de prazer foram maiores após a ingestão de cafeína, sugerindo que neste modelo de exercício estas variáveis perceptivas também podem ter contribuído para o efeito ergogênico da cafeína observado no desempenho. Em conclusão, este estudo demonstrou que a cafeína melhorara o desempenho no ciclismo em ambos os modelos de exercício aeróbio de alta intensidade, sendo no contrarrelógio devido ao aumento da quantidade total de energia anaeróbia e no carga constante até a exaustão nas variáveis perceptíveis e alteração no acoplamento excitação-contração, sem alterar o limiar de fadiga periférica / The present thesis investigated the effect of caffeine on cycling performance, muscle recruitment, energetic contribution, blood lactate, physiological and perceptual responses and the development of central and peripheral fatigue in different models of high-intensity aerobic exercises. Nine male cyclists (32.3 ± 6.0 years old, 79.3 ± 6.8 kg, 181.2 ± 7.9 cm and VO2max 55.2 ± 5.7 mL.kg-1.min-1) completed 11 experimental sessions. The participants performed 4,000 m cycling time trial, constant-load to exhaustion in the average power output of the time trial (313 ± 41 W and 100 ± 10 rpm), and also performed constant-load with fixedtime corresponding to 60% of the time sustained in the constant-load to exhaustion (237.2 ± 56.0 s). Participants ingested capsules containing placebo or caffeine (5 mg.kg-1 body weight) 60 minutes prior to the tests, in a counterbalanced order and in a double-blind model. Cardiorespiratory and perceptual responses were measured during the tests. Blood lactate was collected before and after exercises. Neuromuscular assessments were performed via electrical femoral nerve stimulation at Baseline (prior to capsule ingestion), Pre-EX (one hour after capsules ingestion, before exercise), and Post-EX (2 min after exercise). 5 mg.kg-1 of caffeine improved their performance in the 4,000 m cycling time trial (-6.9 ± 7.4 s; p = 0.024), due to an increase in anaerobic contribution. The performance in the constant-load to exhaustion was also enhanced after caffeine intake (+134.3 ± 81.5 s; p = 0.001), but in this case accompanied by greater aerobic contribution. Caffeine intake prior to cycling performance provided an ergogenic effect in the 4,000 m time trial and in the constant-load to exhaustion, without altering the critical threshold of peripheral fatigue. Among the peripheral components evaluated, the maximum rate of force development significantly reduced less after the constant-load to exhaustion in the caffeine condition, even as the prolonged exercise time, and also reduced significantly less after the constant-load with fixed-time, which suggests that caffeine may have altered the excitation-contraction coupling, which resulted in delayed peripheral fatigue. In addition, during the constant-load to exhaustion test, the felt arousal and feeling were higher after the caffeine, suggesting that in this exercise model these perceptions may also have contributed to the observed ergogenic effect of caffeine on the cycling. In conclusion, this study demonstrated that caffeine improved the cycling performance in both models of high-intensity aerobic exercise, being in the time-trial due to the increase of the total amount of anaerobic energy and the constant load until the exhaustion due to alteration in the perceptible variables and in the excitation-contraction coupling, without change the peripheral fatigue threshold

Every year, about 1 million patients worldwide and 16000 patients in Sweden undergo total hip arthroplasty (THA). This surgical intervention is considered a successful, safe and cost-effective procedure to regain pain-free mobility and restore hip joint function in patients suffering from severe hip joint disease or trauma. Besides relieving the pain, restoration of biomechanical forces around the hip with appropriate femoral offset (FO), leg length and proper component position and orientation are important goals. The radiographic preoperative planning and postoperative evaluation of these parameters require good validity, interobserver reliability and intraobserver reproducibility. It remains controversial as to how much postoperative leg length discrepancy (LLD) and FO change are acceptable. Generally, lengthening of the operated leg ≥ 10mm and FO reduction of the operated hip > 5mm should be avoided by using preoperative radiological templating and intraoperative measurement methods. There is no consensus on the association between LLD and FO and outcome after THA. The aims of this thesis were to: 1. To determine the influence of non-corrected LLD after THA on patients’ reported hip function and quality of life (QoL). 2. To study the association of global FO changes after THA with patients’ reported hip function, QoL and abductor muscle strength. 3. To evaluate the concurrent validity of the Sundsvall method of measuring postoperative global FO by comparing it to a standard method and to evaluate the interobserver reliability and intraobserver reproducibility of measurement of postoperative global FO, LLD and acetabular cup inclination and anteversion. 4. To analyse the postoperative radiographs of THA patients with leg lengthening and FO reduction to determine whether the problem is located in the stem, cup or both. Study I: A prospective cohort study of 174 patients with unilateral osteoarthritis (OA), comparing patients with lengthening ≥ 10mm, restoration (between 9 mm lengthening and 5 mm shortening) or shortening > 5 mm of the operated leg after THA. Follow up was 12–15 months. We found that a LLD of up to 20 mm did not influence the functional outcome (WOMAC) or QoL (EQ-5D). However, the lengthening group showed less improvement in WOMAC and more use of a shoe lift. Study II: A prospective cohort study of 222 patients with unilateral hip OA, comparing patients with decreased global FO (> 5 mm reduction), restored FO (within 5 mm restoration), and increased FO (> 5 mm increment) after THA. Follow up was was 12–15 months. The unadjusted results showed that the decreased FO group had a worse WOMAC index, less abductor muscle strength, and more use of walking aids. When these results were adjusted for possible confounding factors, only global FO reduction was statistically significantly associated with reduced abductor muscle strength. The incidence of residual hip pain and analgesics use was similar in the 3 groups. Study III: A prospective cohort study of 90 patients with primary unilateral OA treated with THA. Global FO using the Sundsvall method, global FO (standard method), LLD, acetabular cup inclination and anteversion were measured on postoperative radiographs. The interobserver reliability and intraobserver reproducibility were tested using three independent observers. We found that the Sundsvall method is as reliable as the standard method and the evaluated radiographic measurement methods have the required validity and reliability to be used in clinical practice. Study IV: A prospective cohort study of 174 patients with unilateral primary OA treated with THA. LLD and global FO were measured on postoperative radiographs. Patients with lengthening of the operated leg ≥ 10mm (n=41) and patients with reduction of global FO > 5mm (n=58) were further studied to investigate the amount of lengthening and global FO reduction that took place in the stem and in the cup compared with the contralateral side. The interobserver reliability and intraobserver reproducibility were tested using two independent observers. We found that post-THA lengthening of the operated leg ≥ 10mm was mainly caused by improper placement of the femoral stem, whereas a decrease of global FO > 5 was caused by improper placement of both acetabular and femoral components. The radiological measurement methods used showed substantial to excellent interobserver reliability and intraobserver reproducibility and are therefore clinically useful. The main conclusions of this thesis are: LLD up to 20 mm and reduced global FO more than 5 mm did not influence the functional outcome or quality of life at 12–15 months postoperatively. Lengthening ≥ 10mm was associated with increased use of a shoe lift. A reduction of global FO more than 5 mm compared to the contralateral hip was associated with weaker hip abductor muscles and more use of walking aids. Therefore both should be avoided. The radiographic measurement methods of LLD, global FO, cup inclination and anteversion have the required validity and reliability to be used in clinical practice. Lengthening of the operated leg is mainly caused by improper femoral stem positioning while global FO reduction results from improper positioning of both acetabular and femoral components. Surgeons should be aware of these operative pitfalls in order to minimize component malpositioning. / Varje år opereras ungefär 1 miljon patienter runt om i världen och 16000 patienter i Sverige med en total höftledsprotes (THA). Operation med höftledsprotes anses vara enav de mest framgångsrika, säkra och kostnadseffektiva kirurgiska åtgärderna med syfte att för att återställa livskvalité. Målet är att smärtlindra och återställa rörligheten i dendestruerade höftleden vid artros, reumatisk destruktion eller men efter exempelvis Perthes sjukdom. Vid operation med THA är det viktigt att återställa de biomekaniskakrafterna runt höftleden med en adekvat så kallad femoral offset (FO), postoperativ benlängdsskillnad (BLS) och ett tillfredsställande komponentläge. Den preoperativaplaneringen och den postoperativa bedömning av dessa parametrar kräver god tillförlitlighet, det vill säga validitet och reproducerbarhet både mellan olika bedömareoch vid upprepade mätningar av samma bedömare. Det är fortfarande inte klarlagt hur mycket postoperativ förändring i FO och BLS som är acceptabla. I dagsläget är detacceptabelt om den postoperativa benförlängningen understiger 1 cm och förändringen i FO är under 5 mm. Det finns ingen konsensus huruvida det föreligger ett sambandmellan BLS, FO och den patientrapporterade höftfunktionen och livskvalitén efter THA. Syftet med denna avhandling var: 1. Att studera effekten av icke-korrigerad BLS efter THA på den patientrapporterade höftfunktionen och livskvalitén. 2. Att studera effekten av förändringen i FO efter THA på den patientrapporterade höftfunktion, livskvalitén och muskelstyrka i abduktion. 3. Att utvärdera validitet och reliabilitet av en så kallad global FO genom att jämföra den med den gällande standard metoden samt studera tillförlitlighet av de radiologiskamätningar av postoperativa BLS, FO, cup inklination och anteversion efter THA. 4. Att radiologiskt undersöka i vilken av komponenterna (stam eller cup) somförändringen i FO och BLS verkar vara förlagd. Studie I: En prospektiv kohortstudie med 174 patienter som behandlats med THA för en primär unilateral koxartros. Patienterna delades in i tre grupper; de som fått en BLSförlängning över 10mm, återställning (mellan 9mm förlängning och 5mm förkortning) eller förkortning >5mm av det opererande benet efter THA. Uppföljning gjordes 12-15månader postoperativt. Vi fann att BLS upp till 20mm påverkade inte höftfunktion (WOMAC) och livskvalité (EQ-5D), men den förlängda gruppen visade en mindreförbättring i WOMAC och rapporterade en mer frekvent användning av skoinlägg. Studie II: En prospektiv kohortstudie med 222 patienter som behandlats med THA för en primär unilateral koxartros. Patienterna delades in i tre grupper; de patienter medförminskad FO (> 5mm minskning), återställd FO (inom 5mm) eller ökad FO (>5mm ökning). Uppföljning genomfördes efter 1 år med WOMAC, styrkemätning av höftensabduktorer och en frågeformulär. En minskad FO var associerade med en minskad styrka i höftens abduktorer. Det var ingen skillnad mellan grupperna gällandekvarstående höftsmärta och användning av analgetika. Studie III: En prospektiv kohortstudie med 90 patienter som behandlats med THA på grund av primär unilateral koxartros. På de postoperativa röntgenbilderna uppmättesglobala FO (Sundsvalls metodologi), globala FO (standard metod), BLS, cup inklination och anteversion. Reliabilitet och reproducerbarhet bedömdes mellan treoberoende observatörer. Vi fann att global FO (enligt Sundsvalls metodologi) är lika tillförlitlig som den nuvarande standardmetoden och de utvärderade radiologiskamätmetoderna har hög validitet och reliabilitet och kan således användas i klinisk praxis. Studie IV: En prospektiv kohortstudie med 174 patienter som behandlats med en THA för en primär unilateral koxartros. På de postoperativa röntgenbilderna uppmättes BLSoch globala FO. Patienter med förlängning ≥ 10mm (n=41) och patienter med minskning av globala FO >5mm (n=58) studerades for att mäta förlängning ochglobala FO minskning som sitter i stammen eller i cup jämfört med kontralaterala sidan. Reliabilitet och reproducerbarhet bedömdes av två oberoende observatörer. Vifann att en BLS över 10mm sitter framför allt i stamkomponenten i lårbenet medan en minskning i FO över 5 mm sitter i båda stam och cup. De radiologiska mätmetodernahar hög reliabilitet och reproducerbarhet och kan således användas i klinisk praxis. De viktigaste slutsatserna i denna avhandling är: 1. BLS med en förlängning upp till 20 mm och en minskning av globala FO mer än 5 mm påverkar inte patientrapporterad höftfunktion eller livskvalitet 1 år postoperativt. 2. BLS med en förlängning mer än 9 mm var associerad med mer användning av skoinlägg. En minskad FO med mer än 5 mm jämfört med den icke opererade höftenvar associerad med en sämre muskelstyrka i abduktion och ökat användning av gånghjälpmedel. 3. De radiologiska mätmetoderna av BLS, FO, acetabulära komponentens inklination och anteversion har hög validitet och reliabilitet, vilket kan användas i klinisk praxis. 4. En förlängning av det opererade benet orsakas främst av en positioneringen av stamkomponenten i lårbenet medan förlust av FO beror på otillfredsställande placeringav både stam och den acetabulära komponenten. Kirurger bör vara medveten om dessa operativa fallgropar för att optimera det kirurgiska resultatet.

Total Hip Arthroplasty (THA) is an orthopaedic procedure that is performed to reduce pain and restore the functionality of hip joints that are affected by degenerative diseases. The outcomes of THA are generally good. However, the stress shielding of the periprosthetic femur is a factor that can contribute towards the premature loosening of the femoral stem. In order to improve the stress shielding characteristics of metallic femoral stems, stiffness configurations that offer more flexibility should be considered. This research has investigated the potential of more flexible and lightweight cobalt chromium molybdenum (CoCrMo) femoral stems that can be manufactured using Selective Laser Melting (SLM). Square pore cellular structures with compressive properties that are similar to human bone have been presented and incorporated into femoral stems by utilising fully porous and functionally graded designs. A three dimensional finite element model has been developed to investigate and compare the load transfer to the periprosthetic femur when implanted with femoral stems offering different stiffness configurations. It was shown that the load transfer was improved when the properties of the square pore cellular structures were incorporated into the femoral stem designs. Factors affecting the manufacturability and production of laser melted femoral stems have been investigated. A femoral stem design has been proposed for cemented or cementless fixation. Physical testing has shown that a functionally graded stem can be repeatedly manufactured using SLM, which was 48% lighter and 60% more flexible than a traditional CoCrMo prosthesis. The research presented in this thesis has provided an early indication of utilising SLM to manufacture lightweight CoCrMo femoral stems with levels of flexibility that have the potential to reduce stress shielding in the periprosthetic femur.

Informações em tempo real da direção e tipo de fluxo sanguíneo podem ser obtidas com ultrassonografia com Doppler. Não foram encontrados dados na literatura de valores obtidos por este método da artéria celíaca e mesentérica cranial de gatos. Além disso, ocasionalmente há necessidade de sedar os gatos e cães para realização deste exame em quaisquer vasos em que se deseja obter mais informações. O trabalho possui dois objetivos. Um foi avaliar os aspectos quantitativos da onda espectral formada pelo fluxo sanguíneo das artérias: aorta, celíaca, mesentérica cranial, renal, ilíaca externa e femoral de gatos e cães hígidos; e compará-los aos obtidos dos mesmos animais submetidos à sedação, com um protocolo para cada espécie. Os gatos foram sedados com midazolam, cetamina e butorfanol, e os cães, com acepromazina e butorfanol. Outro objetivo foi obter valores velocimétricos de referência para artéria celíaca e artéria mesentérica cranial em gatos, através do Doppler espectral. Para isso, foram avaliados 20 gatos e 20 cães hígidos. Como resultado dos gatos, foram obtidos os valores de pico de velocidade sistólica, velocidade diastólica final, média da velocidade média, média da velocidade máxima, índice de resistividade e índice de pulsatilidade, tanto da artéria celíaca quanto da artéria mesentérica cranial de animais hígidos não sedados, e; foram obtidos esses mesmos dados das artérias aorta, renal, ilíaca externa e femoral e todos comparados entre os gatos sedados e não sedados, onde não foram encontradas diferenças estatisticamente significativas, exceto na velocidade diastólica final e velocidade média da artéria celíaca, e índice de resistividade e de pulsatilidade da artéria ilíaca. Já nos cães, observou-se que houve diferença de pelo menos dois dos parâmetros dopplervelocimétricos avaliados das artérias selecionadas, exceto da artéria femoral. Dessa forma, nos gatos foram fornecidos parâmetros dopplervelocimétricos da artéria celíaca e mesentérica cranial de animais não sedados, e conclui-se que, enquanto o protocolo utilizado nos gatos, com midazolam, cetamina e butorfanol, não alterou os valores encontrados nos vasos selecionados, exceto da artéria celíaca e da ilíaca; nos cães, o uso de acepromazina e butorfanol levou a modificação de parte desses valores em todos os vasos, exceto na artéria femoral. Assim, na realização deste exame com esses protocolos, essas diferenças devem ser consideradas. / Real time information about direction and type of blood flow can be obtained with Doppler ultrasound. No data was found in the literature regarding values of the celiac and cranial mesenteric artery in cats obtained through this method. Moreover, occasionally, for examining cats and dogs’ vessels about which we desire to get more information, there is a need to sedate these animals. This study has two objectives. One was to evaluate the quantitative aspects of spectral wave formed by the blood flow of aorta, celiac, cranial mesenteric, renal, external iliac and femoral arteries from healthy cats and dogs and compare them to the same animal under sedation, using one protocol for each species. The cats were sedated with midazolam, ketamine and butorphanol and the dogs with acepromazine and butorphanol. The second objective was to obtain velocimetric reference values from celiac and mesenteric cranial artery in cats. Twenty healthy cats and dogs were evaluated. As a result for the cats, values of peak systolic velocity, end diastolic velocity, time averaged mean velocity, time averaged maximum velocity, resistivity index and pulsatility index of both the celiac and the cranial mesenteric artery were obtained in healthy non-sedated animals, and; these same data from aorta, renal, external iliac and femoral were obtained, and all compared, between sedated and non-sedated cats, where statistically significant differences were not found, except in end diastolic velocity and average speed of the celiac artery, and resistance and pulsatility index of the iliac artery. In dogs, a difference was observed in at least two of the Doppler velocity parameters measured of the arteries, except for the femoral artery. Thus, Doppler velocity parameters of the celiac and cranial mesenteric artery in non-sedated cats were provided and it was concluded that the protocol used in cats, with midazolam, ketamina and buthorphanol did not alter the values of Doppler ultrasound in the selected vessels in cats, except celiac and external iliac artery. In addition, in dogs, the use of acepromazine and buthorphanol led to modification of part of these values in all vessels, except in the femoral artery. Thus, when carrying out this examination with these protocols, such differences should be considered.

Groin hernia is common, and each year 200 repairs per 100 000 adult inhabitants are performed in Sweden. Groin hernias are either inguinal or femoral (2-4%). Elective repair is not associated with an excess mortality, but adverse outcomes include recurrence and long-term pain. Emergency procedures have a 4% mortality rate with an increased risk for bowel resection and postoperative complications. The aim of this thesis was to identify risk factors for adverse outcomes and to propose measures to improve groin hernia treatment. Twenty-three per cent of female hernias were femoral. Thirty-six per cent of femoral hernias, and 5% of inguinal hernias, have emergency procedures. Females (OR 1.47) and patients above 65 years-of-age (OR 2.24) were at higher risk for emergency repair. Bowel resection was performed in 23% of emergency femoral repairs, and the 30-day mortality was 10 times that of an age- and gender-matched population. The majority of emergency patients were unaware of their hernia, and one third had previously had no groin symptoms. Femoral repairs were at larger risk for recurrence than inguinal repairs. The surgical techniques with least risk for recurrence were preperitoneal mesh repairs (open HR 0.28, and laparoscopic HR 0.31). Long-term pain was present in 24% of femoral hernia patients, of whom 5.5% described pain interfering with daily activities. The only factor predicting the risk for long-term pain was pain preoperatively. Pain decreased with time. In a randomized study on inguinal hernia, TEP resulted in less pain six weeks after surgery than Lichtenstein repair performed under local anesthesia (LLA). TEP patients were to a larger extent able to perform sporting activities. No difference was seen in intra-operative complications. Femoral hernias should be given high priority for repair and preperitoneal techniques should be used. Earlier diagnosis, in the elective setting, is probably difficult to attain. Heightened awareness in the emergency department is required. TEP is safe, and results in less pain than LLA six weeks after surgery. A widening of indications for TEP in primary inguinal hernia repair is justifiable.

Displaced femoral neck fractures comprise more than a third of all hip fractures. There is controversy as to the optimal treatment. Despite attempts to improve the methods for internal fixation, complication rates have been almost unchanged: 20-40% non-union and late segmental collapse in another 10-20%. Internal fixation has been the preferred treatment in Scandinavia, whereas primary hemi- or total arthroplasty have been more prevalent in the rest of Europe and North America. In this study, patients 75 years or older, including those with mental impairment, were randomized to either internal fixation or cemented primary total hip arthroplasty (THA). A total of 146 hips in 143 patients were followed for two years. After one year 23% had died, and after two years 29%. Mortality was about the same in both groups. The accumulated mortality was pronounced among the mentally impaired patients. In the internal fixation group, 44% underwent further surgery. In the THA group, 18% dislocated. The dislocation rate was higher for the mentally impaired patients. The Harris hip scores were higher in the THA group, whereas pain was more common in the internal fixation group. The first 50 patients in each treatment group were studied concerning heterotopic ossification (HO), a well-known complication after THA. The incidence of HO in the THA group was similar to what is found after THA due to osteoarthritis. However, only 1/39 developed severe symptoms. A subgroup of 100 patients was included in a study concerning nutritional status and functional capacity using the Modified Norton scale, Katz index of ADL and a questionnaire measuring instrumental activities of daily living. The THA group fared better concerning weight change over time, locomotion and pain. The nutritional intervention did not show any measurable effects. All patients were followed until two years postoperatively and all fracturerelated hospital costs, including reoperations, were calculated. We found no difference in total costs between the treatment groups. Costs to the municipality were calculated comparing the baseline cost before surgery with the average cost per month during the first postoperative year. No difference was found between the treatment groups. On the basis of our results, we recommend arthroplasty for patients in this age group with normal mental function and high functional demands.

Although blood viscosity is an important component in determining vascular function, it is often assumed constant. Emerging evidence linking individual differences in viscosity to cardiovascular disease casts doubt on this assumption. The purpose of this study was to determine the contribution of whole blood viscosity to key measures of vascular function. To address this aim as comprehensively as possible, first, whole blood viscosity was compared with traditional risk factors for cardiovascular disease. Then flow-mediated dilation (FMD), carotid-femoral pulse wave velocity (cfPWV), and carotid artery compliance were calculated either with or without blood viscosity taken into account. Lastly, we tested whether the removal of blood viscosity could influence well-established associations between age and vascular function. Blood viscosity and vascular function were measured in 97 adults ranging in age from 18-63 years. No significant differences were observed between whole blood viscosity and traditional risk factors for cardiovascular disease. Whole blood viscosity was not significantly correlated with FMD, cfPWV, and carotid compliance. As expected, age was positively correlated with cfPWV (r=0.65, p<0.001) and negatively correlated with FMD (r=-0.21, p<0.05) and carotid compliance (r=-0.45, p<0.01). Even after controlling for viscosity, these relationships remained statistically significant (cfPWV r=0.65, p<0.001; FMD r=-0.24, p<0.05; carotid compliance r=-0.44, p<0.05). These results indicate that whole blood viscosity does not appear to significantly impact measures of vascular function and that the rationale for including whole blood viscosity in the calculation of vascular function remains weak. / text