Orientador: Alberto Cliquet Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-11T22:08:58Z (GMT). No. of bitstreams: 1 Ravaglia_FabioFerrazdoAmaral_M.pdf: 3548953 bytes, checksum: 43be45b122388651863a7129f73a3c73 (MD5) Previous issue date: 2008 / Mestrado / Cirurgia / Mestre em Cirurgia

The presented Master Thesis is focused on the structural analysis of the proximal femur on which the Proximal Femoral Nail (PFN) and Proximal Femoral Tele-Screw (PFT) systems are applied. These systems are used for a treatment of the intertrochanteric and femoral neck fractures. However, in some cases a loss of stability of the systems may be expected. The presented thesis describes a development of numerical models in which stress distribution of implants and strain distribution of bone tissue are compared. Numerical models were created from real objects. The model of femur geometry was created by using the Computed Tomography (CT). Boundary conditions of the model were estimated from the force equilibrium of the lower limb. All numerical models were processed in the commercial package ANSYS Workbench v15.0. It is shown that the hip screws of the PFN system result in lower equivalent stresses than the screws of the PFT system. Maximal strains of the bone tissue, when using the PFN system, are situated near the fracture, close the hip screw thread. For the PFT system, the maximal strains are only near the area of fracture.

Topology-based optimization techniques and lattice structures are powerful ways to accomplish lightweight components with enhanced mechanical performance. Recent developments in additive manufacturing (AM) have led the way to extraordinary opportunities in realizing complex designs that are derived from topology and lattice-based structural optimization. The main aim of this work is to give a contribution, in the integration between structural optimization techniques and AM, by proposing a setup of a proper methodology for rapid development of optimized medical implants addressing oseeointegration and minimization of stress shielding related problems. The validity of the proposed methodology for a proof of concept was demonstrated in two real-world case studies: a tibia intramedullary implant and a shoulder hemi prosthetics for two bone cancer patients. The optimization was achieved using topology optimization and replacement of solid volumes by lattice structures. Samples of three lattice unit cell configurations were designed, fabricated, mechanically tested, and compared to select the most proper configuration for the shoulder hemi prosthesis. Weight reductions of 30% and 15% were achieved from the optimization of the initial design of the tibia intramedullary implant and the shoulder hemiprosthesis respectively compared to initial designs. Prototypes were fabricated using selective laser melting (SLM) and direct light processing (DLP) technologies. Validation analysis was performed using finite element analysis and compressive mechanical testing. Future work recommendations are provided for further development and improvement of the work presented in this thesis.

INTRODUÇÃO: As fraturas diafisárias do fêmur e da tíbia encontram-se em destaque devido a sua elevada incidência e alto impacto econômico e social. A osteossíntese com uso da haste intramedular (HIM) é o procedimento cirúrgico de escolha. A infecção de sítio cirúrgico (ISC) relacionada a HIM é considerada uma complicação grave e de difícil tratamento. OBJETIVOS: 1. Determinar a incidência de ISC após a implantação de HIM para fixação de fraturas diafisárias de fêmur e tíbia. 2. Avaliar os possíveis fatores associados. MÉTODOS: Estudo prospectivo observacional do tipo coorte. Para definição de ISC, foram utilizados os critérios do CDC-NHSN. A incidência de ISC foi calculada como a relação entre o número de pacientes com ISC em relação ao número total de pacientes. Para avaliação dos potenciais fatores associados, foram analisados aqueles relacionados aos pacientes (idade, gênero, índice de massa corpórea, presença de focos ativos de infecção à distância, presença condições imunossupressoras, avaliação de estado físico segundo escore ASA, etilismo, tabagismo, uso de drogas ilícitas, politrauma, etiologia do trauma, tipo de fratura quanto à exposição óssea, classificação da fratura segundo Müller AO, classificação segundo Tcherne para as fraturas fechadas, classificação segundo Gustilo-Anderson para as fraturas expostas, permanência em outro serviço de saúde, uso prévio de fixador externo, antecedente de manipulação cirúrgica na topografia da fratura, uso de hemoderivados); dos fatores relacionados ao ambiente cirúrgico e ao ato operatório (classificação da ferida quanto ao potencial de contaminação, duração da cirurgia, tricotomia, possível contaminação intraoperatória, uso de antimicrobianos relacionados ao procedimento cirúrgico, uso de drenos, ocorrência de hipotermia ou hipóxia no período perioperatório, tipo de HIM utilizada, fresagem, necessidade de necessidade de reparo do revestimento cutâneo associado à topografia da fratura, uso de terapia por pressão negativa) e dos fatores relacionados à microbiota (colonização por S. aureus ou A. baumannii). RESULTADOS: 221 pacientes foram incluídos e completaram o período de 12 meses de seguimento. A incidência de ISC associada à osteossíntese com HIM foi de 11,8%. Na análise inicial por regressão logística não ajustada, os seguintes fatores apresentaram associação com ISC: etiologia do trauma relacionada a acidentes de carro e bicicleta, classificação Müller AO do traço da fratura 2 ou 3, uso prévio de fixador externo, cirurgias com maiores tempos de duração, uso de drenos, uso de terapia por pressão negativa e necessidade de reparo do revestimento cutâneo na topografia da fratura. Na análise ajustada por regressão logística múltipla, contudo, apenas o uso prévio de fixador externo e a necessidade de reparo do revestimento cutâneo mantiveram-se associados à ocorrência de ISC. CONCLUSÕES: A incidência de ISC associada à fixação de fraturas diafisárias de fêmur e tíbia com HIM foi de 11,8%. O uso prévio de fixadores externos e a necessidade de reparo do revestimento cutâneo na topografia da fratura foram fatores associados à ocorrência de infecção / BACKGROUND: Diaphyseal fractures of femur and tibia are prominent due to its high incidence and high economic and social impact. Intramedullary nailing (IN) is the surgical procedure of choice. Surgical site infection (SSI) related to this procedure is considered a difficult to treat complication. OBJECTIVES: Determine the incidence of SSI after IM in femoral and tibial diaphyseal fractures and evaluate possible risk factors. METHODS: Prospective observational cohort study. SSI was defined according to CDC-NHSN criteria. Incidence of SSI was calculated as the ratio between the number of patients with SSI and total number of patients. Analysis of potential risk factors included patients-related factors (age, gender, body mass index, active foci of infection, immunosuppressive conditions, ASA score, alcohol or illicit drug abuse, smoking, polytrauma, etiology of fracture, type of fracture if closed or open, classification of fracture according to Müller AO, Tcherne classification for closed fractures, to Gustilo-Anderson classification for open fractures, previous surgical manipulation, use of blood products); environmental and surgical-related factors (surgical wound classification, duration of surgery, hair removal, intraoperative contamination, antimicrobial use, presence of drains, hypothermia or hypoxia in the perioperative period, type of IN used, reaming, need for muscle or skin flap repair, use of negative pressure therapy) and microbiotarelated factors (S. aureus and A. baumannii colonization). RESULTS: 221 patients were included and completed the 12-month follow-up period. Incidence of SSI was 11.8%. In the initial analysis by unadjusted logistic regression, following factors were associated SSI: trauma etiology related to car and bicycle accidents, Müller AO classification of the fracture morphology groups 2 or 3, previous use of external fixator, surgeries with larger length of time, presence of drains, use of negative pressure therapy and need for muscle or skin flap repair. In the multiple logistic regression-adjusted analysis, previous use of external fixator and need for muscle or skin flap repair remained associated with SSI. CONCLUSIONS: Incidence of SSI associated with IN for femoral and tibial diaphyseal fractures was 11.8%. Previous use of external fixators and need for muscle or skin flap repair were factors associated with occurrence of infection

INTRODUÇÃO: As fraturas diafisárias do fêmur e da tíbia encontram-se em destaque devido a sua elevada incidência e alto impacto econômico e social. A osteossíntese com uso da haste intramedular (HIM) é o procedimento cirúrgico de escolha. A infecção de sítio cirúrgico (ISC) relacionada a HIM é considerada uma complicação grave e de difícil tratamento. OBJETIVOS: 1. Determinar a incidência de ISC após a implantação de HIM para fixação de fraturas diafisárias de fêmur e tíbia. 2. Avaliar os possíveis fatores associados. MÉTODOS: Estudo prospectivo observacional do tipo coorte. Para definição de ISC, foram utilizados os critérios do CDC-NHSN. A incidência de ISC foi calculada como a relação entre o número de pacientes com ISC em relação ao número total de pacientes. Para avaliação dos potenciais fatores associados, foram analisados aqueles relacionados aos pacientes (idade, gênero, índice de massa corpórea, presença de focos ativos de infecção à distância, presença condições imunossupressoras, avaliação de estado físico segundo escore ASA, etilismo, tabagismo, uso de drogas ilícitas, politrauma, etiologia do trauma, tipo de fratura quanto à exposição óssea, classificação da fratura segundo Müller AO, classificação segundo Tcherne para as fraturas fechadas, classificação segundo Gustilo-Anderson para as fraturas expostas, permanência em outro serviço de saúde, uso prévio de fixador externo, antecedente de manipulação cirúrgica na topografia da fratura, uso de hemoderivados); dos fatores relacionados ao ambiente cirúrgico e ao ato operatório (classificação da ferida quanto ao potencial de contaminação, duração da cirurgia, tricotomia, possível contaminação intraoperatória, uso de antimicrobianos relacionados ao procedimento cirúrgico, uso de drenos, ocorrência de hipotermia ou hipóxia no período perioperatório, tipo de HIM utilizada, fresagem, necessidade de necessidade de reparo do revestimento cutâneo associado à topografia da fratura, uso de terapia por pressão negativa) e dos fatores relacionados à microbiota (colonização por S. aureus ou A. baumannii). RESULTADOS: 221 pacientes foram incluídos e completaram o período de 12 meses de seguimento. A incidência de ISC associada à osteossíntese com HIM foi de 11,8%. Na análise inicial por regressão logística não ajustada, os seguintes fatores apresentaram associação com ISC: etiologia do trauma relacionada a acidentes de carro e bicicleta, classificação Müller AO do traço da fratura 2 ou 3, uso prévio de fixador externo, cirurgias com maiores tempos de duração, uso de drenos, uso de terapia por pressão negativa e necessidade de reparo do revestimento cutâneo na topografia da fratura. Na análise ajustada por regressão logística múltipla, contudo, apenas o uso prévio de fixador externo e a necessidade de reparo do revestimento cutâneo mantiveram-se associados à ocorrência de ISC. CONCLUSÕES: A incidência de ISC associada à fixação de fraturas diafisárias de fêmur e tíbia com HIM foi de 11,8%. O uso prévio de fixadores externos e a necessidade de reparo do revestimento cutâneo na topografia da fratura foram fatores associados à ocorrência de infecção / BACKGROUND: Diaphyseal fractures of femur and tibia are prominent due to its high incidence and high economic and social impact. Intramedullary nailing (IN) is the surgical procedure of choice. Surgical site infection (SSI) related to this procedure is considered a difficult to treat complication. OBJECTIVES: Determine the incidence of SSI after IM in femoral and tibial diaphyseal fractures and evaluate possible risk factors. METHODS: Prospective observational cohort study. SSI was defined according to CDC-NHSN criteria. Incidence of SSI was calculated as the ratio between the number of patients with SSI and total number of patients. Analysis of potential risk factors included patients-related factors (age, gender, body mass index, active foci of infection, immunosuppressive conditions, ASA score, alcohol or illicit drug abuse, smoking, polytrauma, etiology of fracture, type of fracture if closed or open, classification of fracture according to Müller AO, Tcherne classification for closed fractures, to Gustilo-Anderson classification for open fractures, previous surgical manipulation, use of blood products); environmental and surgical-related factors (surgical wound classification, duration of surgery, hair removal, intraoperative contamination, antimicrobial use, presence of drains, hypothermia or hypoxia in the perioperative period, type of IN used, reaming, need for muscle or skin flap repair, use of negative pressure therapy) and microbiotarelated factors (S. aureus and A. baumannii colonization). RESULTS: 221 patients were included and completed the 12-month follow-up period. Incidence of SSI was 11.8%. In the initial analysis by unadjusted logistic regression, following factors were associated SSI: trauma etiology related to car and bicycle accidents, Müller AO classification of the fracture morphology groups 2 or 3, previous use of external fixator, surgeries with larger length of time, presence of drains, use of negative pressure therapy and need for muscle or skin flap repair. In the multiple logistic regression-adjusted analysis, previous use of external fixator and need for muscle or skin flap repair remained associated with SSI. CONCLUSIONS: Incidence of SSI associated with IN for femoral and tibial diaphyseal fractures was 11.8%. Previous use of external fixators and need for muscle or skin flap repair were factors associated with occurrence of infection

Bei der Behandlung kindlicher Femurfrakturen ist es wichtig die Besonderheiten des kindlichen Knochens zu berücksichtigen. Resultierende Beinlängendifferenzen sowie die psychosoziale Belastung der Kinder stellen Probleme in der Therapie dar. Ziel der vorliegenden Studie war es unter Berücksichtigung dieser Aspekte einen Vergleich konservativer und operativer Therapieverfahren im Verlauf der Jahre herzustellen. Zugrunde gelegt wurden die Daten von 210 Kindern und Jugendlichen, die in dem Zeitraum von 1992 bis 2008 in der Universitätsmedizin Göttingen an einer Femurfraktur behandelt wurden. Als komplikationsarmes und kindgerechtes Verfahren hat sich in den letzten Jahren die Elastisch Stabile Intramedulläre Nagelung (ESIN) immer mehr durchgesetzt. Sie stellt mittlerweile bei Kindern über vier Jahren das Verfahren der Wahl dar. Die Verwendung der Plattenosteosynthese und des Fixateur externe hat deutlich abgenommen und sollte nur noch Spezialindikationen vorbehalten sein. Bei Kindern unter vier Jahren kann ebenfalls die ESIN mit guten Ergebnissen verwendet werden. Eine Alternative stellt in dieser Altersgruppe der Beckenbeingips dar. Die Extensionsverfahren werden auf Grund der vielen Nachteile, vor allem in psychosozialer Hinsicht, so gut wie nicht mehr verwendet.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A chalcona à um complexo fitoterÃpico derivado da aroeira-do-sertÃo (Myracrodruon urundeuva Fr. All.), planta usada popularmente como antiinflamatÃrio e cicatrizante. Avaliaram-se os efeitos anti-sÃpticos e cicatrizantes das chalconas nas feridas e o seu efeito sobre a consolidaÃÃo Ãssea nas fraturas expostas induzidas em ratos. Utilizaram-se ratos Wistar machos adultos, com peso mÃdio de 300g. A fratura foi realizada no fÃmur esquerdo dos animais e exposta por 3h antes de iniciar o tratamento. Os animais foram distribuÃdos ao acaso em dois grupos: o grupo 1 o foco da fratura foi limpo com 100 mL de soro fisiolÃgico 0,9% e o grupo 2, o foco da fratura foi limpo com 100 mL de soro fisiolÃgico 0,9% e 40 mL de chalconas, na concentraÃÃo de 10 mg de chalcona por 1 mL de soluÃÃo salina a 0,9%. Em todos os animais foram realizadas culturas dos focos de fraturas antes de iniciar o tratamento que consistiu na osteosÃntese intramedular com fio de Kirschener de 1 mm de diÃmetro. Foi realizada a avaliaÃÃo clÃnica e radiolÃgica no pÃs-operatÃrio imediato, no 7Â, 14Â, 21 e 28 dias do tratamento. Na avaliaÃÃo clÃnica verificava-se o aspecto da ferida: sinais flogÃsticos, deiscÃncia da ferida, fÃstula e ferida cicatrizada. No primeiro grupo, a cicatrizaÃÃo ocorreu apÃs a 3 semana em 78,9 % dos animais; no segundo grupo, a cicatrizaÃÃo ocorreu a partir da 2 semana em 50 % dos ratos. Em todos os animais ocorreram contaminaÃÃes, sendo o Staphylococcus aureus o microorganismo isolado mais comumente. No primeiro grupo, 80% dos animais perderam a reduÃÃo na segunda semana, e no segundo grupo, 50% dos animais perderam a reduÃÃo na terceira semana. Conclui-se que a chalcona na concentraÃÃo testada nÃo tem efeito na consolidaÃÃo da fratura exposta induzida em rato, porÃm à benÃfica na cicatrizaÃÃo da ferida operatÃria.

This master's thesis is focused on determination and analysis of stress and strain in femur with distraction intramedullary nail for treating leg length discrepancy with the method of distraction osteogenesis. Thesis is mainly focused on states after distraction when the callus consolidates. Problem of determining stress and strain is solved by computational modeling using FEM. Detailed description of modeling is included in this thesis, complicated 3D geometry of bone was acquired from segmentation of CT images. Computational model is solve with 4 different types of callus geometry and also material properties of callus are varied. The influence on stress and strain when the middle distal screw is not applied is also analyzed.

The dachshund, a chondrodystrophic dog breed, presents a unique challenge in the treatment of tibial fractures by having short and curvaceous tibiae, leading to high implant failure risk. In this study, intramedullary pins with full cerclage wires as an option in the treatment of oblique diaphyseal tibial fractures was studied in vitro. This fixation technique was biomechanically compared with the current gold standard in internal stabilization, namely bone plates and screws. Twenty tibiae recovered from adult dachshund cadavers were randomly allocated into two groups of ten bones each. Oblique fractures running in a proximo-cranial-disto-caudal direction in the middle third of the tibial diaphysis were simulated by osteotomy and each bone repaired by using one of the following methods: <ul> <li> Pre-bent intramedullary pin, filling 40% to 60% of the medullary cavity at its narrowest point, inserted normograde and combined with a set of three full cerclage wires (group 1).</li> <li> Lag screw at the osteotomy site, combined with a six hole 2.7 mm contoured dynamic compression plate and cortical screws in neutral mode (group 2).</li> </ul> Each test specimen was subjected to a two point single cycle axial compression test by applying a standardized, increasing compression load to the point of fixation failure or bone collapse. A stress-strain graph for each test specimen was drawn from the raw data. Radiographs and digital photographs were made pre-osteotomy, post-osteotomy, post-repair and post-test, and modes of failure noted for each test specimen. Stress (applied load) and strain (deformation) at yield, ultimate strength, and at failure were determined for each test specimen from the stress-strain graphs and the mean values statistically compared between the groups using the ANCOVA method. Significance levels of p < 0.05 were used, while p < 0.1 and p < 0.01 were also indicated. In group 1, 50% specimens failed due to unraveling or slippage with displacement of the cerclage wires, 30% due to bone fracture at a cerclage wire, and 20% due to bone fracture elsewhere. In group 2, 80% specimens failed due to bone fracture at one or more of the screw holes, whereas 20% failed due to bone fracture not directly associated with implants. No bone plate or screw underwent plastic (permanent) deformation, whereas 80% of the intramedullary pins and 30% of the cerclage wires underwent plastic deformation. Mean stress at the yield point in groups 1 and 2 were 0.323 MPa and 0.403 MPa respectively, at the point of ultimate strength 0.383 MPa and 0.431 MPa respectively, and at the failure point 0.345 MPa and 0.403 MPa respectively. Mean strain at the yield point in groups 1 and 2 were 0.296% and 0.362% respectively, at the point of ultimate strength 0.412% and 0.472% respectively, and at the failure point 0.713% and 0.838% respectively. Clinically, there was an indication that plates and screws were more resistant to deformation by the loads applied than intramedullary pins and cerclage wires. However, statistically, there were no significant differences in stress at yield (p = 0.299), ultimate strength (p = 0.275), or failure (p = 0.137) between the two groups. Similarly, there were no significant differences in strain at yield (p = 0.684), ultimate strength (p = 0.778), or failure (p = 0.505) between the two groups. Main limitations of the study were the relatively small number of specimens tested, the smoothness of the osteotomy cuts which limited interdigitation between the fragments, and that only three of the five recognized loads acting on bones in vivo, were tested in vitro. In conclusion, this study did not show enough evidence to prove a significant difference between the two methods of fixation. Therefore, it is suggested that intramedullary pins and full cerclage wires be used as an acceptable alternative to bone plates and screws in the treatment of oblique mid-diaphyseal tibial fractures in chondrodystrophic dog breeds. / Die dachshund, ‘n chondrodistrofiese honderas, bied ‘n unieke uitdaging in die behandeling van frakture van die tibia, deurdat hulle tibias kort en krom is, wat lei tot ‘n hoë risiko van inplantaat mislukking. In hierdie studie is intramedullêre penne met vol sirkeldrade as ‘n keuse in die behandeling van skuins frakture van die tibiale skag in vitro bestudeer. Hierdie tegniek van herstel is vergelyk met die huidige goue standaard in interne stabilisering, naamlik beenplate en skroewe. Twintig tibias wat van volwasse dachshund kadawers herwin is, is lukraak aan twee groepe van tien bene elk toegewys. Skuins frakture in ‘n proksimo-kranio-disto-koudale rigting in die middelste derde van die tibiale skag is nageboots deur ‘n osteotomie, waarna elke been herstel is deur die gebruik van een van die volgende metodes: <ul> <li> Vooraf gebuigde intramedullêre pen, wat 40% tot 60% van die murgholte by die dunste punt vul, normograad geplaas en gekombineer met ‘n stel van drie vol sirkeldrade (groep 1).</li> <li> Trekskroef by die osteotomie area, gekombineer met ‘n ses-gat 2.7 mm gekontoerde dinamiese drukplaat en kortikale skroewe geplaas op neutrale wyse (groep 2).</li> </ul> Elke toetsmonster is onderwerp aan ‘n twee-punt enkel siklus aksiale druktoets deur die toepassing van ‘n gestandardiseerde, verhogende druklading tot by die punt van fiksasie breuk of kollaps van die been. ‘n Druk-spanning grafiek vir elke toetsmonster is vanaf die rou data saamgestel. X-straalfoto’s en digitale foto’s van elke been is pre-osteotomie, post-osteotomie, post-herstel and post-toets geneem en die maniere van faal vir elke toetsmonster aangeteken. Druk (toegepaste lading) en spanning (vervorming) by meegee (“yield”), treksterkte (“ultimate strength”) en faal (“failure”) is vir elke toetsmonster bepaal vanaf die druk-spanning grafieke en die gemiddelde waardes statisties vergelyk tussen die groepe deur gebruik te maak van die ANCOVA metode. Beduidenis vlakke van p < 0.05 is gebruik, terwyl p < 0.1 en p < 0.01 ook aangedui is. In groep 1 het 50% toetsmonsters gefaal as gevolg van losgaan of gly van die sirkeldrade met verplasing, 30% as gevolg van beenfrakture by ‘n sirkeldraad, en 20% as gevolg van beenfrakture elders. In groep 2 het 80% toetsmonsters gefaal as gevolg van beenfrakture by een of meer skroefgate, terwyl 20% gefaal het as gevolg van beenfrakture wat nie direk met die inplantate geassosieer is nie. Geen beenplaat of skroef het plastiese (permanente) vervorming ondergaan nie, terwyl 80% van die IM penne en 30% van die sirkeldrade plastiese vervorming ondergaan het. Gemiddelde druk by die meegeepunt in groepe 1 en 2 was 0.323 MPa en 0.403 MPa onderskeidelik, by die punt van treksterkte 0.383 MPa en 0.431 MPa onderskeidelik, en by die faalpunt 0.345 MPa en 0.403 MPa onderskeidelik. Gemiddelde spanning by die meegeepunt in groepe 1 en 2 was 0.296% en 0.362% onderskeidelik, by die punt van treksterkte 0.412% en 0.472% onderskeidelik, en by die faalpunt 0.713% en 0.838% onderskeidelik. Klinies was daar ‘n indikasie dat plate en skroewe meer weerstandbiedend was teen vervorming deur die toegepaste ladings as intramedullêre penne en sirkeldrade. Statisties was die druk wat die toetsmonster laat meegee (p = 0.299), en die druk by die treksterkte- (p = 0.275) en faalpunte (p = 0.137) egter nie beduidend verskillend tussen die twee groepe nie. Net so was die spanning by die meegee- (p = 0.684), treksterkte- (p = 0.778) en faalpunte (p = 0.505) nie beduidend verskillend tussen die twee groepe nie. Hoof beperkings van die studie was die relatief klein getal monsters wat getoets is, die gladheid van die osteotomie-snitte wat interdigitasie tussen die fragmente beperk het, en dat slegs drie van die vyf erkende ladings wat op bene in vivo inwerk, in vitro getoets kon word. Laastens het hierdie studie nie genoeg getuienis opgelewer om ‘n beduidende verskil te bewys trussen die twee metodes van herstel nie. Derhalwe word voorgestel dat IM-penne en vol sirkeldrade gebruik word as aanvarbare alternatief tot beenplate en skroewe in die behandeling van skuins midskag tibia frakture in chondrodistrofiese honderasse. / Dissertation (MSc)--University of Pretoria, 2012. / Companion Animal Clinical Studies / unrestricted

INTRODUÇÃO: As fraturas do terço médio da clavícula representam 80% das fraturas claviculares e seu tratamento é motivo de discussão na literatura ortopédica. Estudos prévios relativos ao tratamento cirúrgico têm demonstrado bons resultados clínicos com o uso das placas de reconstrução ou a fixação intramedular elástica estável com hastes flexíveis de titânio. O objetivo deste estudo foi a comparação desses métodos no tratamento das fraturas do terço médio da clavícula, quanto aos resultados funcionais, parâmetros radiográficos, dor pós-operatória, taxa de satisfação e taxa de complicações. MÉTODOS: Neste ensaio clínico comparativo, prospectivo e randomizado, 59 pacientes com fratura desviada do terço médio da clavícula foram alocados aleatoriamente para receberem osteossíntese com placa de reconstrução (33 pacientes - grupo Placa) ou haste flexível de titânio (26 pacientes - grupo Haste). O desfecho primário do estudo foi a avaliação funcional pelo escore DASH aos 6 meses de pós-operatório. Os desfechos secundários foram: o escore DASH aos 12 meses; o escore de Constant- Murley aos 6 e 12 meses; o tempo de consolidação da fratura; o encurtamento residual; o nível de dor pela escala visual analógica no 1º pósoperatório; a taxa de pacientes satisfeitos e a taxa de complicações. RESULTADOS: Cinquenta e quatro pacientes completaram o seguimento, sendo 29 do grupo Placa e 25 do grupo Haste. O escore DASH médio aos 6 meses foi de 9,9 pontos no grupo Placa e 8,5 no grupo Haste, sem diferença estatisticamente significante (p = 0,329). Da mesma forma, não houve diferenças significantes no escore DASH aos 12 meses ou no escore de Constant aos 6 e 12 meses. O tempo de consolidação foi equivalente entre os grupos (p = 0,352), enquanto o encurtamento residual foi maior no grupo Placa, com significância estatística (p = 0,032), mas sem relevância clínica (0,4 cm). Os resultados da escala visual analógica para dor no 1º pósoperatório e a taxa de pacientes satisfeitos foram similares entre os grupos. O grupo Placa apresentou mais casos com angulação do implante (11 casos) do que o grupo Haste (um caso) (p = 0,003), enquanto o grupo Haste foi mais associado à dor relacionada ao implante (10 casos), em comparação ao grupo Placa (4 casos) (p = 0,035). Não houve diferenças significantes entre os grupos quanto às complicações maiores, incluindo falha do implante, infecção pós-operatória, pseudoartrose e reoperação. CONCLUSÕES: A osteossíntese das fraturas desviadas do terço médio da clavícula com placa de reconstrução ou haste flexível de titânio produzem resultados semelhantes quanto aos escores funcionais, tempo de consolidação, dor pós-operatória, satisfação dos pacientes e complicações maiores. As placas de reconstrução são mais suscetíveis à angulação do implante, enquanto as hastes flexíveis de titânio causam mais dor relacionada ao implante / INTRODUCTION: Midshaft clavicle fractures represent 80% of all clavicular fractures, and their treatment is controversial in the literature. Previous studies have shown good clinical results in patients with midshaft clavicular fractures treated with reconstruction plate fixation or elastic stable intramedullary nailing (ESIN). The objective of this study was to compare these methods in terms of functional results, radiographic parameters, postoperative pain, satisfaction rates and complication rates. METHODS: In this prospective, randomized, controlled trial, 59 patients with displaced midshaft clavicular fractures were randomly assigned to receive either reconstruction plate (33 patients - Plate group) or ESIN fixation (26 patients - ESIN group). The primary outcome was the DASH score at 6 months. The secondary outcomes were the following: DASH score at 12 months; Constant-Murley scores at 6 and 12 months; time to fracture union; residual shortening; visual analog scale for pain on the first post-operative day; percentage of satisfied patients; and complications rates. RESULTS: Fifty-four patients completed the follow-up, 29 in the Plante group and 25 in the ESIN group. The mean DASH score at 6 months was 9.9 in the plate group and 8.5 in the ESIN group, with no significant difference (p = 0.329). Similarly, there were no differences in the DASH score at 12 months or the Constant-Murley scores at 6 and 12 months. The time to union was equivalent between the groups (p = 0.352), whereas the residual shortening was significantly greater in the plate group (p = 0.032) but was not clinically relevant (0.4 cm). The visual analog scale scores for pain and the percentage of satisfied patients were similar between the groups. Implant bending was significantly more common in the plate group (eleven patients) than in the ESIN group (one patient) (p = 0.003), whereas hardware-related pain was more frequent in the ESIN group (10 patients vs. 4 patients) (p = 0.035). There were no differences in terms of major complications, including implant failure, postoperative infection, nonunion and reoperation. CONCLUSIONS: Reconstruction plates and ESIN yielded similar results in terms of functional results, time to union, post-operative pain, patient satisfaction and major complications in patients with displaced midshaft clavicular fractures. Reconstruction plates are more susceptible to implant bending, whereas ESIN causes more hardwarerelated pain