Total hip replacement (THR) is one of the most successful and most frequently performed operations. For most implants the published rate of revision at 10 years is less than 10%. However the revision rates are higher for younger and more active patients who are likely to outlive their implants. The most frequent cause of THR failure is aseptic loosening, commonly accompanied by bone loss at the implant site. THR revisions give worse functional results and fail sooner than primary THR and are complicated by this loss of bone stock. A resurfacing hip prosthesis replaces the diseased surface layer of bone and cartilage and retains the majority of the femoral head. The stress distribution in the proximal femur is closer to that in an intact hip. A conservative resurfacing prosthesis will present the surgeon with no greater problems at revision than encountered at primary conventional 11-JR. Early designs of resurfacing prosthesis conserved femoral bone stock at the expense of acetabular bone. Revision rates were high and while some failures were caused by avascular necrosis and femoral neck fracture the predominant cause was acetabular loosening. The design of a bone conserving prosthesis requires knowledge of the shape of the bony surfaces of the hip joint. A survey of the morphology of the acetabulum showed a wide variation in shape. While early resurfacing designs had hemispherical acetabular cups the bony surface is less than hemispherical. The morphology and desired range of hip motion constrain prosthesis thickness and shape. A novel resurfacing design using a polyacetal femoral component and an UHMWPE acetabular component is proposed. This bearing combination has a lower volumetric wear rate than an equivalent Co-Cr on UHWMPE bearing. Computer modelling of the resurfacing concept showed that lower moduli materials reduced stress shielding and distributed implant-bone interface stresses more evenly. Mechanical testing of polyacetal following immersion in Ringer's solution showed substantial decreases in Young's modulus while strength was unaffected.

The paper presents the development of instrumentaria designed to solve ACL lesions using hamstrings (tendons of semitendinosus and m. gracilis - ST / G). The work itself took place in two phases. Part of the first phase was the development of its own instrumentation, including the implant designed to fix hamstrings tendons. The inherent part of the development was the performance of both mechanical and functional tests. The most tested element of the instrumentation was the screw with eye. In the course of its development, mechanical tests of tensile strength were carried out on the individual variants of the solution, and then the rapture of the screw with the eye from animal bone - simulating the function of the product in a real environment. Part of this was the development of methodology and work with new instrumentation. Clinical testing was performed in the second stage and the results of the operations are part of the work. The self-developed ACL lesion reconstruction toolkit is designed to use a graft made up of four strands of the above tendons. In the experimental part of the instrumentation development, the suitability of the implant for clinical use has been demonstrated. The newly developed instrumentation for ACL reconstruction, using the test implant for fixation of the hamstrings...

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

A ATM pode ser afetada por lesões que alteram sua morfologia e comprometem sua função, levando o cirurgião, algumas vezes, a ter a necessidade de ressecá-la e reconstruí-la. A reconstrução dos defeitos ósseos articulares, congênitos ou adquiridos, é um desafio para o Cirurgião Buco-Maxilo-Facial, podendo ser realizado com materiais aloplásticos, que excluem a necessidade de área doadora, minimizando a morbidade. Entre estes destacamos as próteses totais da articulação temporo-mandibular, estudados até sua forma e composição atual e que possibilitou o estabelecimento de protocolos bem definidos para sua utilização. Destacamos a prótese de estoque da W. Lorenz, com componentes de alta tecnologia e indicações precisas que possibilita grande melhora clínico e funcional. Este estudo avaliou clínico e funcionalmente 15 pacientes tratados no período de oito anos, demonstrando que apesar da melhoria funcional evidente observada, em especial para os casos de anquilose em ATM, ainda muitos estudos e acompanhamento devem ser realizados para se estabelecer, ao longo do tempo, se estas próteses suprem de forma eficiente e duradoura a fisiologia estomatognática ideal. / The TMJ can be affected by injuries that alter its morphology and compromise its normal function, leading the surgeon, sometimes, to have the need to resect it and rebuild it. The reconstruction of the bone articular defects, congenital or acquired, which has been a challenge for the maxillofacial surgeon can be achieved by using aloplastic materials. The use of aloplastics materials precludes the need for a donor area, minimizing the morbidness. Among these, we highlight the temporo-mandibular joint total prosthesis, studied until achieving its current form and composition, and which enabled the establishment of clear protocols for its use. Among these, we highlight the W.Lorenz prosthesis with high technology and specific details that enable a large clinical and functional improvement. This study evaluated important clinical and functional aspects observed in 15 patients treated over a period of eight years, showing that despite the clear functional improvement, particularly observed in cases of TMJ ankylosis, many more studies and monitoring should be conducted to establish, especially in the long term, that these prosthesis supply the stomatognathic system with an effective and durable physiology.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

A ATM pode ser afetada por lesões que alteram sua morfologia e comprometem sua função, levando o cirurgião, algumas vezes, a ter a necessidade de ressecá-la e reconstruí-la. A reconstrução dos defeitos ósseos articulares, congênitos ou adquiridos, é um desafio para o Cirurgião Buco-Maxilo-Facial, podendo ser realizado com materiais aloplásticos, que excluem a necessidade de área doadora, minimizando a morbidade. Entre estes destacamos as próteses totais da articulação temporo-mandibular, estudados até sua forma e composição atual e que possibilitou o estabelecimento de protocolos bem definidos para sua utilização. Destacamos a prótese de estoque da W. Lorenz, com componentes de alta tecnologia e indicações precisas que possibilita grande melhora clínico e funcional. Este estudo avaliou clínico e funcionalmente 15 pacientes tratados no período de oito anos, demonstrando que apesar da melhoria funcional evidente observada, em especial para os casos de anquilose em ATM, ainda muitos estudos e acompanhamento devem ser realizados para se estabelecer, ao longo do tempo, se estas próteses suprem de forma eficiente e duradoura a fisiologia estomatognática ideal. / The TMJ can be affected by injuries that alter its morphology and compromise its normal function, leading the surgeon, sometimes, to have the need to resect it and rebuild it. The reconstruction of the bone articular defects, congenital or acquired, which has been a challenge for the maxillofacial surgeon can be achieved by using aloplastic materials. The use of aloplastics materials precludes the need for a donor area, minimizing the morbidness. Among these, we highlight the temporo-mandibular joint total prosthesis, studied until achieving its current form and composition, and which enabled the establishment of clear protocols for its use. Among these, we highlight the W.Lorenz prosthesis with high technology and specific details that enable a large clinical and functional improvement. This study evaluated important clinical and functional aspects observed in 15 patients treated over a period of eight years, showing that despite the clear functional improvement, particularly observed in cases of TMJ ankylosis, many more studies and monitoring should be conducted to establish, especially in the long term, that these prosthesis supply the stomatognathic system with an effective and durable physiology.

No description available.