<p>Validerat; 20101217 (root)</p>

Introdução: Com o desenvolvimento das artroplastias não cimentadas, estudos vêm sendo realizados com o objetivo de se determinar se as hastes femorais não cimentadas poderiam ser utilizadas em qualquer paciente,ou estaria reservada apenas para aqueles que possuem boa qualidade óssea. Um estudo comparativo é realizado para avaliar a osteointegração de hastes femorais não cimentadas nas artroplastias totais de quadril em pacientes que apresentam má qualidade óssea, comparando com pacientes que apresentam boa qualidade óssea. Materiais e métodos: Este estudo inclui 196 pacientes submetidos à artroplastia total do quadril primária não cimentada por diagnóstico de osteoartrite primária e secundária com no mínimo de 12 meses de seguimento, divididos em dois grupos: um contendo pacientes com boa qualidade óssea (DorrA); e outro com pacientes com má qualidade óssea (Dorr B e C). Foi avaliada a osteointegração através da análise radiográfica seguindo os critérios estabelecidos por Engh, além de avaliar o resultado clínico e funcional através do questionário de WOMAC. Foram também avaliadas as complicações decorrentes do processo cirúrgico em ambos os grupos. Resultados:Há diferença na frequência do gênero no grupo Má Qualidade Óssea (MQO) (p=0,009) com predomínio de mulheres e diferença no diagnóstico inicial,havendo um número maior de casos de patologias reumatológicas e sequelas de displasia no grupo MQO (p=0,0002). Não observamos diferença quanto a idade, lado operado e tempo de seguimento entre os dois grupos. Não observamos diferença entre os grupos quando avaliado o escore clínico, a osteointegração ou a necessidade de revisão. Observamos um maior risco de fratura intraoperatória do fêmur proximal no grupo MQO (p=0.03) comparando-se com o grupo Boa Qualidade Óssea (BQO). Conclusão: Concluímos que as hastes femorais não cimentadas osteointegram igualmente, independentemente da qualidade óssea do paciente e que fraturas intraoperatórias ocorrem mais quando realizadas hastes femorais não cimentadas em pacientes com má da qualidade óssea / Introduction: With the development of the non cemented total hip replacement, many studies were carried out to determinate if uncemented femoral stem can be used in every patient, or if this kind of implants are reserved for those patients with good bone quality. A comparative study was carried out to evaluate the osseointegration of uncemented femoral stem in total hip replacements in patients that have poor bone quality, comparing with patients that have good bone quality. Methods: The study included 196 cases of primary uncemented total hip arthroplasties due to a diagnosis of primary or secondary osteoarthritis, with a minimum of 12 months of follow-up, divided in two groups: one with patients that have good bone quality (Type A Dorr), and another with patients that have poor bone quality (Types B and C Dorr). Osseointegration was evaluated by X ray analysis, following the Engh\'s criteria. Clinical and functional results were also evaluated by the application of the WOMAC questionnaire, and complication in both groups were reported. Results: Regarding our patient\' gender, we observed a significant difference between the two groups: there was more women in the group of Poor Bone Quality (PBQ) (p=0,009). We also observed a significant difference in the initial diagnosis of the patients: there was more osteoarthritis secondary to rheumatic pathologies and hip dysplasia in the PBQ group (p=0,0002). There was no difference when observed the mean age, operation\' side and mean time of follow-up between the two groups. We also did not observed differences between the groups when evaluated the clinical scores, the osseointegration of the femoral stem and the need of revision of the arthroplasty by any reason. But, in the PBQ, we observed a higher risk of intra operative fracture in the proximal femur compared with the group Good Bone Quality (GBQ) (p=0,03). Conclusion: We concluded that the uncemented femoral stem has an equal rate of osseointegration, despite the bone quality and that there is a higher risk of intra operative fracture when implanted an uncemented femoral stem in bone with poor quality

L’objectif de ce travail de thèse était d’évaluer les bénéfices thérapeutiques d’un entraînement par imagerie motrice chez les patients ayant subi une prothèse totale de genou unilatérale. Combiner l’imagerie motrice avec la physiothérapie classique a permis de diminuer la douleur et d’augmenter la force du quadriceps durant la phase aiguë, au 1er mois postopératoire. Durant la phase chronique, au 6ème mois postopératoire, l’imagerie motrice permettrait de corriger l’asymétrie de la marche, d’une part en augmentant la force du quadriceps ipsilatéral et, par conséquent, en accentuant la charge sur le genou opéré, et d’autre part en augmentant la flexion maximale du genou durant la phase oscillante. L’imagerie motrice pourrait également aider les personnes âgées après la prothèse totale du genou à monter les escaliers plus rapidement, en toute sécurité. Cela peut atténuer le risque de chute dans les escaliers et, par conséquent, diminuer la fréquence des blessures graves. En conclusion, intégrer l’imagerie motrice dans les programmes de rééducation après prothèse totale du genou primaire unilatérale est pertinent et prometteur / The primary aim of the present work was to determine the therapeutic benefits of a specific motor imagery training. Combining motor imagery with classical physical therapy was found to be effective in reducing pain and increasing quadriceps strength after total knee arthroplasty during the acute phase at the first month postoperatively. During the chronic phase, at the 6th month postoperatively, motor imagery might contribute to correct the asymmetry of gait by increasing the strength of the ipsilateral quadriceps and, consequently accentuating the weight loading on the operated knee, as well as by improving knee proprioception through an increase in the maximum knee flexion during the swing phase. MI might also help elderly people after total knee arthroplasty to climb stairs more quickly, easily, and safely. This could attenuate the risk of falls on stairs, and consequently decrease the frequency of major injuries. In summary, the integration of motor imagery in clinical rehabilitation programs after primary unilateral total knee arthroplasty is relevant and promising

A evolução da artroplastia total do quadril (ATQ) tem sido auxiliada por informações geradas a partir de estudos de análise de marcha, sendo possível avaliar objetivamente a função do quadril após a substituição total da articulação. Seus resultados podem ser utilizados para estudar fatores que poderiam influenciar no resultado da cirurgia, como tipos de acesso, implantes e reabilitação pós-operatória. A abordagem lateral direita, descrita por Hardinge em 1982 apresenta uma excelente exposição à porção anterior do quadril e do fêmur proximal, porém com uma potencial desvantagem que é a secção da parte anterior do músculo glúteo médio do trocânter maior. Apesar da sua reinserção adequada, pode haver insuficiência abdutora após ATQ, em decorrência da avulsão pós-operatória desta sutura, resultando em fraqueza abdutora, comprometendo a marcha. O objetivo do estudo foi comparar parâmetros cinemáticos da marcha após ATQ primária pela via de acesso lateral direta utilizando dois tipos de sutura da musculatura abdutora. Fizeram parte do estudo 43 pacientes com osteoartrite do quadril unilateral submetidos à ATQ primária pela via de acesso lateral direta. A alocação dos pacientes foi feita de modo quase randomizado, sendo 19 pacientes submetidos à sutura do tipo transóssea e 24 à sutura do tipo transtendínea. Foram avaliados os parâmetros cinemáticos da marcha dos pacientes no período pré-operatório e com seis meses de pós-operatório, e em relação ao tipo de sutura da musculatura abdutora. Não houve diferença estatística nos parâmetros cinemáticos da marcha avaliados em relação ao tipo de sutura da musculatura abdutora na ATQ primária pela via de acesso lateral direta. / The evolution of total hip arthroplasty (THA) has been improved by information produced from gait analysis, and it is possible to objectively evaluate hip function after a total joint replacement. The results can be used to study the factors that influence the outcome of the surgery, such as types of access, implants and postoperative rehabilitation. The lateral direct surgical approach described by Hardinge in 1982 provides an excellent exposure to the anterior portion of the hip joint and proximal femur, but with drawbacks that is the necessity to detach the anterior and medial part of the gluteus medius muscle from the greater trochanter to obtain access to the hip joint. Despite its adequate reinsertion, there may be abductor insufficiency after THA, as a consequence of the postoperative avulsion of this suture, resulting in abductor weakness, compromising the gait. The objective of the study was to compare gait parameters after THA via the direct lateral approach using two types of abductor muscle suture. The study included 43 patients with unilateral hip osteoarthritis who have undergone primary THA performed via direct lateral surgical approach. The patients were allocated in a quasi-randomized manner, 19 of whom were submitted to transosseous suture and 24 to transtendineal suture. The kinematic parameters of the gait of patients were analyzed preoperatively and 6 months after surgery, and in relation to the type of the abductor muscle suture. There was no statistically significant difference regarding the kinematic gait parameters between the two types of the abductor muscle suture in the THA via the direct lateral surgical approach.

Este estudo objetivou avaliar o perfil clínico e epidemiológico de pacientes submetidos à cirurgia de prótese de quadril e que sofreram complicações relacionadas a esta no pós-operatório. A pesquisa foi realizada no período de 2002 a 2006; a amostra inicial foi composta de 398 cirurgias de pacientes submetidos à Artroplastia Primária de Quadril, realizadas em um hospital escola especializado da Cidade de São Paulo. Em 48 destas cirurgias ocorreram complicações pós-operatórias, compondo a amostra final deste estudo. Houve predominância de indivíduos do sexo feminino (66,7%), com média de idade de 59 anos, casados ou em união estável/amasiado (43,4%), provenientes da cidade de São Paulo (55,3%). Referente à escolaridade a maioria (58,1%) tinha fundamental completo. Quanto à ocupação houve predominância de aposentados e pacientes que desenvolvem atividades técnicas e ocupacionais, ambos com 35,1%. Infecção do quadril foi o motivo predominante para revisão da prótese de quadril (33,3%). A Vancomicina e a Ceftazidima, associadas, foram os antibióticos mais utilizados (58,1%). O estudo contribui para a estruturação de um cuidar multidisciplinar e especializado, pois possibilita o conhecimento da clientela, através de um perfil sociodemográfico e clínico, proporcionando mecanismos para intervenções de modo a transformar a assistência de Enfermagem em Ortopedia e Traumatologia e Reabilitação Física / This study was aimed at evaluating the clinical and epidemiological profile of patients submitted to hip prosthesis surgery who had complications related to it in the post-surgery period. The research was conducted between 2002 and 2006; the initial sample was comprised of 398 surgeries of patients submitted to Primary Hip Arthroplasty, performed at a specialized school hospital in the city of São Paulo. In 48 of those surgeries there were post-surgery complications, thus comprising the final sample of this study. There was a predominance of females (66.7%), with average age of 59, married or with a stable union (43.4%), living in the city of São Paulo (55.3%). Regarding education, most (58.1%) had finished primary school. As for occupation, the majority were retirees and patients that perform technical and occupational activities, both with 35.1%. Hip infection was the most common cause for hip prosthesis revision (33.3%). Vancomycin and ceftazydime, used together, were the most used antibiotics (58.1%). The study helps the development of a multidisciplinary, specialized care because it brings information about the clientele through a socio-demographic and clinical profile, thus providing mechanisms for interventions so as to transform care in Orthopedic and Traumatology Nursing and in Physical Rehabilitation Nursing

Prosthetic joint infection (PJI) is an emergent concern given the wide usage of prosthetic joints in old and young population to assist with activities of daily living. While the public health burden of PJI appears to be relatively low compared with other potentially fatal infections such as blood stream infections, PJI is associated with excess morbidity and steep healthcare costs. Appropriate and timely diagnosis and management are crucial in preventing poor clinical outcomes and restoring adequate function in patients with PJI. There is lack of studies using robust epidemiologic methods to evaluate effectiveness of existing treatment protocols for PJI. We conducted retrospective studies using the Veterans Affairs (VA) database using data from 123 VA hospitals between 2003 and 2012. We also abstracted clinical data from VA medical records to achieve the objectives of this research. The effectiveness of an antibiotic — rifampin and a surgical management – exchange arthroplasty was assessed in separate studies. These treatments were adjudicated based on their effectiveness in prevention of PJI recurrence and two-year postoperative mortality, respectively. Seven hundred thirty-one of the 2838 patients with first episode of PJI were treated with surgery and medical management for Staphylococcus aureus PJI and were retained in the thesis dataset. In the first study, we compared 300 patients treated with rifampin for the first 42 days of treatment period to 364 patients treated with antibiotics other than rifampin during the 42 days (unexposed). Overall, 255 patients (38.4%) were observed to have a treatment failure defined as recurrence of S. aureus PJI with or without a repeat surgery or death in the 90 days after surgery for the PJI. The rifampin-treated and unexposed groups did not differ on time to treatment failure (p=0.92). It was noted that patients treated with a less invasive surgery that resulted in retention of the infection prosthesis with removal of infected tissue and rifampin treatment had lower risk for treatment failure compared to patients with similar surgery but not treated with rifampin (HR=0.79, 95%CI 0.52-1.20). We also observed that patients who had surgery for removal of the infected prosthesis and were treated with rifampin had significantly greater risk for treatment failure compared to those treated with the prosthesis removal surgery but no rifampin. In our second study we further analyzed this research question in depth using advanced epidemiologic methods to attenuate any bias in our previous findings. We noted that the groups did not differ in their risk for treatment failure after matching patients on their probability of receiving rifampin treatment (HR=1.08, 95%CI 0.71-1.65). In addition, we observed that patients whose treatment decision with rifampin was determined by the rifampin prescription rate in the treating facility substantially benefited with use of rifampin antibiotic for S. aureus PJI. In the third study we assessed the effectiveness of a surgery — exchange arthroplasty (involves removal of infected prosthesis and insertion of new prosthesis) to reduce the risk of death two years after surgery in a sample of 566 S. aureus PJI patients. Patients with this procedure were compared to patients treated with retention of their infected prosthesis and removal of infected tissue (DAIR). Overall, 90 patients (15.9%) died in the 2 years after surgery. Of these, 14 (9.9%) died after exchange surgery while 76 (17.9%) died after the DAIR procedure. We observed that the exchange surgery reduced the risk for death by almost 60% compared to the DAIR (OR=0.42, 95%CI 0.19-0.89). In conclusion, epidemiological studies conducted as part of this thesis identified considerable burden of treatment failure (38.4%) and all-cause mortality (15.9%) among veterans treated for S. aureus PJI. Rifampin combination antibiotic regimen was not observed to be effective in reducing the burden of the infection, in comparison to other antibiotics. Exchange arthroplasty reduced the risk for death in old veteran patients compared to a less invasive but potentially life-threatening procedure such as DAIR. Choice of treatment should be made on a case-by-case basis for patients with S. aureus PJI after thorough consideration of patient characteristics.

Computational modeling in the field of biomechanics is becoming increasingly popular and successful in practice for its ability to predict function and provide information that would otherwise be unobtainable. Through the application of these new and constantly improving methods, kinematics and joint contact characteristics in pathological conditions of femoroacetabular impingement (FAI) and total hip arthroplasty (THA) were studied using a lower extremity computational model. Patients presenting with FAI exhibit abnormal contact between the femoral neck and acetabular rim leading to surrounding tissue damage in daily use. THA is the replacement of both the proximal femur and acetabular region of the pelvis and is the most common surgical intervention for degenerative hip disorders. A combination of rigid osteoarticular anatomy and force vectors representing soft tissue structures were used in developing this model. Kinematics produced by healthy models were formally validated with experimental data from Burnfield et al. This healthy model was then modified to emulate the desired morphology of FAI and a THA procedure with a range of combined version (CV) angles. All soft tissue structures were maintained constant for each subsequent model. Data gathered from these models did not provide any significant differences between the kinematics of healthy and FAI but did show a large amount of variation in all THA kinematics including incidents of dislocation with cases of lower CV angles. With the results of these computational studies performed with this model, an increased understanding of hip morphology with regards to STS has been achieved.

Total ankle arthroplasties (TAAs) are mechanical devices used to replace the articular surfaces of the ankle joint in order to relieve pain for patients with osteoarthritis. Since most osteoarthritis is post-traumatic, and due to the highly variable individual foot geometry, TAAs are rarely inserted into normal geometry. This leads to serious problems with stresses and contact pressures in TAA components. This study uses finite element (FE) modeling to determine how hindfoot alignment, or how far in varus or valgus the most distal part of the calcaneus is perpendicularly from the axis of the tibia, affects the stresses and contact pressures in the articulating surfaces of two different TAA models. To investigate the effects of foot alignment on hardware stresses after TAA, FE models were generated. Models of the mobile bearing, three component Scandinavian Total Ankle Replacement (STAR) and the fixed bearing, two component Zimmer Trabecular Metal Total Ankle (Zimmer) were generated from laser scans of the hardware and virtually implanted into 3D models of the tibia and talus. Ligaments were modeled as linear springs to impart physiologically realistic flexibility in the model. The stance phase of a walking gait cycle was applied and stresses and contact pressures at the articulation between model components were recorded for various degrees of hindfoot alignment [1]. Data analyzed shows that both models have areas of high concentrations of stress and contact pressure. The Zimmer TAA seems to favor a valgus alignment due to the lower stresses and contact pressures in valgus alignments compared to varus. Though the STAR does not generally favor one alignment over the other, it does have significantly lower stresses and contact pressures than the Zimmer. These differences may be due to the geometric congruency of the STAR versus the anatomical articulation of the Zimmer.

Reverse shoulder arthroplasty (RSA) is performed to decrease pain and improve function and range of motion (ROM) primarily for patients with rotator cuff arthropathy, an arthritis of the shoulder secondary to rotator cuff insufficiency. However, RSA has suffered from high early to mid-term rates of complication, with instability being one of the most common. The shoulder biomechanics post-RSA depend on multiple factors such as implant geometry, positioning, and cuff integrity. This study built upon prior finite element (FE) analysis of RSA to investigate the effects of glenoid lateralization and retentive liner design on shoulder stability. A previously validated FE model was extended to model shoulder external rotation (ER) after implantation of the Zimmer Trabecular Metal RSA system. The FE model included the scapula bone with an implanted glenosphere implant, the humerus bone with implanted humeral sections of the RSA implant, and muscle tendons representing the subscapularis, infraspinatus, and deltoid. Six different models matched glenospheres in three cases of lateralization (2mm, 4mm, and 10mm) with two humeral poly liner designs (normal: 150° neck shaft angle or retentive: 155° neck shaft angle). Using Abaqus/Explicit FE software, the proximal ends of the soft tissues were pulled to their anatomical positions, and then fixed in space while the humerus was externally rotated 80° about the humeral long axis from a neutral position with the shoulder abducted 25°. The displacements, deltoid and subscapularis forces, impingement-free ROMs, and subluxation gap distances were recorded. Although greater glenosphere lateralization was associated with higher impingement-free ROM, larger deltoid and subscapularis forces developed. Deltoid tension contributes to shoulder stability and control, but elevated amounts of deltoid tension may contribute to scapular fractures and greater stress at impingement sites post-RSA. Further analysis such as inclusion of more anatomical features and additional motions may offer greater insight to orthopedic surgeons when planning for RSA insertion.

The cause and best treatment option for mechanical low back pain due to disc degeneration remains unsolved, despite `spinal fusion' being the gold standard of surgical treatment, post conservative care, for a very long time. However, the potential drawbacks of spinal fusion and the ongoing evolution in the understanding of normal and symptomatic spine biomechanics, biology and mechanobiology in conjunction with the advancements in material sciences, and tissue engineering has led to a change in the clinical perspective towards treatment methodologies for spinal disorders. Clinically, a gradual shift in philosophy is being observed from a `one size fits all', i.e. spinal fusion for all patients with symptomatic low back pain to a `customized approach', i.e. patient and indication specific treatment modalities for spine care. This philosophy has laid the ground for concepts of `motion preservation' and `dynamic stabilization', the former being an established treatment modality in orthopedics for a long time. The aim of the current study is to perform a comprehensive scientific investigation to understand, evaluate and establish the in vitro biomechanical characteristics and performance of indication specific treatment modalities incorporating the concept of Posterolateral Disc Arthroplasty and Posterior Dynamic Stabilization for the treatment of symptomatic mechanical back pain. The results of this comprehensive study may help the clinicians to make an informed decision while selecting and designing a treating modality for their patients. To this end, the current thesis was undertaken to study the biomechanics of indication specific treatment modalities like motion preservation and dynamic stabilization with a goal to guide clinical and product development decision making. Through the comprehensive biomechanical investigation conducted in the current thesis we were able to theoretically prove the importance of a customized approach towards the treatment of spine care. Also, the most important conclusion of the biomechanical investigation was the fact that Range of Motion results alone are not sufficient to draw significant conclusions. It is imperative that in depth analysis of the quality of motion through the determination of instantaneous center of rotation is extremely important. Previous studies have shown only a single center of rotation between the extremes of motion which is also insufficient as the end points do not determine the path taken to reach the endpoints. This in depth analysis is also important for biomedical engineers to design and develop physiologically viable implants that will mimic the performance of the physiologic spine. Clinical studies are extremely important as a next step towards validating this customized approach towards spine care.