No description available.

Rupture of the anterior cruciate ligament (ACL) is a major clinical problem, leading to instability of the knee joint. This is especially unfortunate, as ACL failure is most commonly encountered in sports, where it affects healthy, younger people who wish to pursue an active life-style. Due to the frequency and potential severity of injuries, a need still exists for information on the biomechanical properties of ligaments under loading conditions, which occur at the time of trauma. The aims of this study were to examine the effect of different loading conditions on the mechanical properties and the appearance of the ruptured ligaments when viewed by scanning electron microscopy. Examining the appearance of collagen fibres at these surfaces should help us understand more about what actually happens during and after the fracture process. This study represents a combination of the two fields of tissue mechanics and fracture morphology for understanding the failure of biological tissues. (Abstract shortened by UMI.)t.

No description available.

A instabilidade do ombro é a incapacidade de manter a cabeça umeral centralizada na fossa glenóide. Os requisitos para o diagnóstico clínico incluem história clínica, exame físico geral e testes objetivos para avaliar a presença e o grau de instabilidade do ombro. O objetivo do presente trabalho é comparar os achados por imagem das alterações anatômicas da artrotomografia computadorizada multislice com a artrorressonância magnética na avaliação da instabilidade do ombro correlacionando com os achados artroscópicos assim como verificar a eficácia da artrotomografia computadorizada multislice na avaliação das alterações anatômicas relacionadas com a instabilidade do ombro. Trata-se de um estudo prospectivo onde, inicialmente, 30 pacientes com o diagnóstico clínico de instabilidade do ombro foram submetidos à artrotomografia computadorizada com cortes de espessura de 0,5 mm e reconstrução a cada 3 mm e à artrorressonância magnética nas seqüências convencionais ponderadas em T1 e T2 com e sem saturação de gordura. Comparado com a artroscopia, a artrorressonância magnética mostrou uma sensibilidade de 93,33% para lesão labral superior, 96,30% para lesão labral anterior e 83,3% para lesão labral ântero-superior e a artrotomografia computadorizada multislice mostrou uma sensibilidade de 90%, 88,89% e 77,78%, respectivamente. A sensibilidade da artrorressonância magnética para lesão de cartilagem articular foi de 16,67% comparado com uma sensibilidade 33,30% da artrotomografia computadorizada multislice. A artrorressonância magnética e artrotomografia computadorizada multislice mostraram a mesma sensibilidade para detecção da lesão de Hill-Sachs (100%), lesão labral ântero-inferior (100%), anormalidades capsulares (88,89%) e lesões de Bankart ósseo (80%). Com base nos resultados, concluímos que a artrorressonância magnética é um método de acurácia superior à artroTCMS na avaliação das lesões labrais ântero-superior, superior e anterior e que a artrotomografia computadorizada multislice mostrou-se eficaz nas estruturas relacionadas à instabilidade, com resultados semelhantes à Artro- RM para o diagnóstico de lesões labrais ântero-inferiores (ALPSA e Bankart), lesões de Hill-Sachs, redundância capsular e Bankart ósseo, sendo superior à artro-RM no diagnóstico de lesões de cartilagem articular / Shoulder instability is characterized by the incapacity to keep the humeral head centered within the glenoid fossa. Clinical diagnosis should include a history of prior events, a complete physical examination, and a set of objective tests to evaluate the presence and extent of shoulder instability. This study aims to compare the imaging of anatomical deformities seen in shoulder instability by employing both multislice computerized tomography (MSCT) arthrography and magnetic resonance arthrography (MRA). A correlation between those images and the arthroscopic findings was important to determining the efficacy of MSCT arthrography in the assessment of shoulder instability. The 30 patients in this prospective study, who had had a previous clinical diagnosis of shoulder instability, underwent CT arthrography using 0.5 mm-thick slices with reconstructions every 3 mm, and T1- and T2-weighted sequential MR imaging arthrography with and without fat saturation. MRA was shown to be 93.33 % sensitive in detecting superior labral lesion, 96.30% in anterior labral lesion, and 83.3% sensitive in anterosuperior labral lesion, whereas the respective results for MSCT arthrography were 90%, 88.89%, and 77.78%. MRA and MSCT arthrography afforded 16.67% and 33.30% sensitivity for joint cartilage injury, respectively. Both techniques were equally sensitive in detecting Hill-Sachs lesion (100%), anteroinferior labral lesion (100%), capsular abnormalities (88.89%), and bony Bankart lesions (80%). The results herein led us to conclude that MRA is more accurate than MSCT arthrography in assessing anterosuperior, superior (SLAP) and anterior labral lesions and the MSCT arthrography had good results in the evaluation of the structures related to shoulder instability. Both methods yielded equivalent results for Hill-Sachs, ALPSA and Bankart lesions. The MSCT arthrography furnished better results than MRA in the diagnosis of articular cartilage lesions

A instabilidade do ombro é a incapacidade de manter a cabeça umeral centralizada na fossa glenóide. Os requisitos para o diagnóstico clínico incluem história clínica, exame físico geral e testes objetivos para avaliar a presença e o grau de instabilidade do ombro. O objetivo do presente trabalho é comparar os achados por imagem das alterações anatômicas da artrotomografia computadorizada multislice com a artrorressonância magnética na avaliação da instabilidade do ombro correlacionando com os achados artroscópicos assim como verificar a eficácia da artrotomografia computadorizada multislice na avaliação das alterações anatômicas relacionadas com a instabilidade do ombro. Trata-se de um estudo prospectivo onde, inicialmente, 30 pacientes com o diagnóstico clínico de instabilidade do ombro foram submetidos à artrotomografia computadorizada com cortes de espessura de 0,5 mm e reconstrução a cada 3 mm e à artrorressonância magnética nas seqüências convencionais ponderadas em T1 e T2 com e sem saturação de gordura. Comparado com a artroscopia, a artrorressonância magnética mostrou uma sensibilidade de 93,33% para lesão labral superior, 96,30% para lesão labral anterior e 83,3% para lesão labral ântero-superior e a artrotomografia computadorizada multislice mostrou uma sensibilidade de 90%, 88,89% e 77,78%, respectivamente. A sensibilidade da artrorressonância magnética para lesão de cartilagem articular foi de 16,67% comparado com uma sensibilidade 33,30% da artrotomografia computadorizada multislice. A artrorressonância magnética e artrotomografia computadorizada multislice mostraram a mesma sensibilidade para detecção da lesão de Hill-Sachs (100%), lesão labral ântero-inferior (100%), anormalidades capsulares (88,89%) e lesões de Bankart ósseo (80%). Com base nos resultados, concluímos que a artrorressonância magnética é um método de acurácia superior à artroTCMS na avaliação das lesões labrais ântero-superior, superior e anterior e que a artrotomografia computadorizada multislice mostrou-se eficaz nas estruturas relacionadas à instabilidade, com resultados semelhantes à Artro- RM para o diagnóstico de lesões labrais ântero-inferiores (ALPSA e Bankart), lesões de Hill-Sachs, redundância capsular e Bankart ósseo, sendo superior à artro-RM no diagnóstico de lesões de cartilagem articular / Shoulder instability is characterized by the incapacity to keep the humeral head centered within the glenoid fossa. Clinical diagnosis should include a history of prior events, a complete physical examination, and a set of objective tests to evaluate the presence and extent of shoulder instability. This study aims to compare the imaging of anatomical deformities seen in shoulder instability by employing both multislice computerized tomography (MSCT) arthrography and magnetic resonance arthrography (MRA). A correlation between those images and the arthroscopic findings was important to determining the efficacy of MSCT arthrography in the assessment of shoulder instability. The 30 patients in this prospective study, who had had a previous clinical diagnosis of shoulder instability, underwent CT arthrography using 0.5 mm-thick slices with reconstructions every 3 mm, and T1- and T2-weighted sequential MR imaging arthrography with and without fat saturation. MRA was shown to be 93.33 % sensitive in detecting superior labral lesion, 96.30% in anterior labral lesion, and 83.3% sensitive in anterosuperior labral lesion, whereas the respective results for MSCT arthrography were 90%, 88.89%, and 77.78%. MRA and MSCT arthrography afforded 16.67% and 33.30% sensitivity for joint cartilage injury, respectively. Both techniques were equally sensitive in detecting Hill-Sachs lesion (100%), anteroinferior labral lesion (100%), capsular abnormalities (88.89%), and bony Bankart lesions (80%). The results herein led us to conclude that MRA is more accurate than MSCT arthrography in assessing anterosuperior, superior (SLAP) and anterior labral lesions and the MSCT arthrography had good results in the evaluation of the structures related to shoulder instability. Both methods yielded equivalent results for Hill-Sachs, ALPSA and Bankart lesions. The MSCT arthrography furnished better results than MRA in the diagnosis of articular cartilage lesions

Posterior lumbar spinal dynamic stabilisation devices are intended to relieve the pain of spinal segments while prolonging the lifespan of adjacent intervertebral discs. This study focuses on the design of such a device, one that has the correct stiffness to stabilise the spinal segment by the correct amount. An initial literature survey covers contemporary topics related to the lumbar spine. Included topics are lumbar anatomy and kinematics, pathology of degenerative disc disease and treatment thereof, other spinal disorders such as spondylolisthesis and spinal stenosis, as well as the complications associated with lumbar dynamic stabilisation. The influence of factors such as fatigue and wear, as well as the properties of appropriate biomaterials are considered when determining the basis of the device design and development. Stabilising the spinal segment begins with correct material selection and design. Various designs and biomaterials are evaluated for their stiffness values and other user requirements. The simplest design, a U-shaped spring composed of carbon fibre-reinforced poly-ether-ether-ketone (CFR-PEEK) and anchored by polyaxial titanium pedicle screws, satisfies the most critical user requirements. Acceptable stiffness is achieved, fatigue life of the material is excellent and the device is very imaging-friendly. Due to financial constraints, however, a simpler concept that is cheaper and easier to rapid prototype was chosen. This concept involves a construct primarily manufactured from the titanium alloy Ti6Al4V extra-low interstitial (ELI) and cobalt-chrome-molybdenum (CCM) alloys. The first rapid prototype was manufactured using an additive manufacturing process (3D-printing). The development of the device was performed in three main stages: design, verification and validation. The main goal of the design was to achieve an acceptable stiffness to limit the spinal segmental range of motion (ROM) by a determined amount. The device stiffness was verified through simple calculations. The first prototype’s stiffness was validated in force-displacement tests. Further validation, beyond the scope of this study, will include fatigue tests to validate the fatigue life of the production-ready device. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

Posterior lumbar spinal dynamic stabilisation devices are intended to relieve the pain of spinal segments while prolonging the lifespan of adjacent intervertebral discs. This study focuses on the design of such a device, one that has the correct stiffness to stabilise the spinal segment by the correct amount. An initial literature survey covers contemporary topics related to the lumbar spine. Included topics are lumbar anatomy and kinematics, pathology of degenerative disc disease and treatment thereof, other spinal disorders such as spondylolisthesis and spinal stenosis, as well as the complications associated with lumbar dynamic stabilisation. The influence of factors such as fatigue and wear, as well as the properties of appropriate biomaterials are considered when determining the basis of the device design and development. Stabilising the spinal segment begins with correct material selection and design. Various designs and biomaterials are evaluated for their stiffness values and other user requirements. The simplest design, a U-shaped spring composed of carbon fibre-reinforced poly-ether-ether-ketone (CFR-PEEK) and anchored by polyaxial titanium pedicle screws, satisfies the most critical user requirements. Acceptable stiffness is achieved, fatigue life of the material is excellent and the device is very imaging-friendly. Due to financial constraints, however, a simpler concept that is cheaper and easier to rapid prototype was chosen. This concept involves a construct primarily manufactured from the titanium alloy Ti6Al4V extra-low interstitial (ELI) and cobalt-chrome-molybdenum (CCM) alloys. The first rapid prototype was manufactured using an additive manufacturing process (3D-printing). The development of the device was performed in three main stages: design, verification and validation. The main goal of the design was to achieve an acceptable stiffness to limit the spinal segmental range of motion (ROM) by a determined amount. The device stiffness was verified through simple calculations. The first prototype’s stiffness was validated in force-displacement tests. Further validation, beyond the scope of this study, will include fatigue tests to validate the fatigue life of the production-ready device. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

Anterior cruciate ligament injury leads to increased sagittal tibial translation, and perceptions of instability and low confidence in the knee joint are common. Many patients have remaining problems despite treatment and are forced to lower their activity level and prematurely end their career in sports. The effect of ACL reconstruction and/or rehabilitation on dynamic knee stability is not completely understood. The overall aim of this thesis was to study the dynamic knee stability during and after rehabilitation in individuals with ACL injury. More specific aims were 1) to elaborate an evaluation method for muscle strength, 2) to evaluate the effect of exercises in closed and open kinetic chain, and 3) to evaluate dynamic knee stability in patients with ACL deficiency or ACL reconstruction. Sagittal tibial translation and knee flexion angle were measured using the CA‐4000 computerised goniometer linkage. Muscle activation was registered with electromyography. The intra‐ and inter‐rater reliability of 1 repetition maximum (RM) of seated knee extension was clinically acceptable. The inter‐rater reliability of 1RM of squat was also acceptable, but the intra‐rater reliability was lower. The systematic procedure for the establishment of 1RM that was developed can be recommended for use in the clinic. One specific exercise session including cycling and a maximum number of knee extensions and heel raises did not influence static or dynamic sagittal tibial translation in uninjured individuals. A comprehensive rehabilitation program with isolated quadriceps training in OKC led to significantly greater isokinetic quadriceps strength compared to CKC rehabilitation in patients with ACL deficiency. Hamstring strength, static and dynamic translation, and functional outcome were similar between groups. Five weeks after ACL reconstruction, seated knee extension produced more anterior tibial translation compared to the straight leg raise and standing on one leg. All exercises produced less or equal amount of anterior tibial translation as the 90N Lachman test. Five weeks after the ACL reconstruction the static and dynamic tibial translation in the ACL reconstructed knee did not differ from the tibial translation on the uninjured leg. Patients in the early phase after ACL injury or ACL reconstruction used a joint stiffening strategy including a reduced peak knee extension angle during gait and increased hamstring activation during activity, which reduces the dynamic tibial translation. Patients with ACL deficiency that completed a four months rehabilitation program used a movement pattern that was more close to normal.

O objetivo da presente dissertação foi avaliar e comparar o comportamento da movimentação do joelho, nos testes Drop Vertical Jump (Drop), Single Hop (Hop), Triple Hop (Triplo), Cross-over Hop (Cross), Six-Meter Timed Hop (6M) e Sidestep Cutting (Sid), através de análises cinemáticas das rotações e velocidades angulares do joelho, e pela co-ativação muscular do membro inferior, em jogadoras de handebol. O desenho experimental da pesquisa foi um estudo transversal, na qual foram avaliadas 12 participantes (idade média de 21,2±2,4 anos, massa corporal média de 68,9±10,3kg e estatura média de 1,70±0,04m). Antes das avaliações, todas foram demarcadas com 25 marcadores retrorefletivos em proeminências ósseas de interesse. Além disso, foram acoplados 10 sensores de eletromiografia (EMG) (EMG TrignoTM Wireless System), nas musculaturas do reto femoral, bíceps femoral e glúteo médio. Após foram aplicados os seis testes funcionais, em três tentativas válidas com o membro dominante. Os dados da cinemática foram obtidos pelo sistema de captura de movimento VICON (Centennial, CO, EUA) e analisados por rotinas desenvolvidas no software MatLab (Mathworks Inc., Natick, MA, USA). Os ângulos de rotação do joelho, especificamente o valgo do joelho, foram obtidos pelos Ângulos de Euler. Já as velocidades angulares escalares foram geradas pelo quatérnion unitário. E por último, as razões de co-ativação entre o reto femoral/bíceps femoral (RB) e reto femoral/glúteo médio (RG) foram através do sinal da integral normalizada da EMG. A partir disso, foram traçados os momentos das variáveis em cada teste avaliado. Para os ângulos de valgo foram extraídos os valores no contato inicial (CI), 40 e 100 ms após o CI, na flexão máxima (Flexmax) e no valgo máximo do joelho (Valgomax). Para as velocidades angulares foram os mesmos instantes, mais o momento de velocidade positiva (Velpos) e velocidade negativa (Velneg). Para as co-ativações foram os mesmos instantes dos ângulos, mais o momento da força pico de reação do solo (FPRS), por duas plataformas de força (Columbus, EUA). Nos ângulos de valgo houve interação [F(2,220)=11,456; p<0,001] na comparação (momento x testes) revelando diferenças significativas nas comparações pareadas. No CI, no 100ms e na Flexmax o Sid apresentou diferença para quase todos os outros testes, assim como o Drop na Flexmax. Nas velocidades angulares houve interação [F(30,330)=14,476; p<0,001] com diferenças significativas nas comparações pareadas. Nos instantes de 40ms, 100ms, Velpos e Velneg o Drop apresentou diferença para quase todos os testes, assim como o 6M apontou diferença para todos os outros testes no 100ms e Velneg. Houve ainda relação moderada: do Cross no momento de Valgomax nas variáveis ângulo de valgo e a velocidade angular (p=0,032); do Sid no momento 40ms nas variáveis do ângulo de valgo e a coativação RB (p=0,015); e no Hop no momento 100ms nas variáveis de ângulo de valgo e a coativação RG (p=0,029). Contudo, pode-se concluir que os testes funcionais de instabilidade dinâmica do joelho para as variáveis cinemáticas apresentam comportamentos específicos. Além disso, ficou demonstrado que o aumento do valgo do joelho no Cross é influenciado pela rapidez da velocidade angular. Podemos concluir ainda, que a adaptação neuromuscular RB, no Sid - 40ms, sofre a influência direta do ângulo de valgo, e que o sinergismo de RG, no Hop - 100ms, é fundamental para o controle do ângulo de valgo do joelho / The objective of this thesis was evaluate and compare the knee movement behavior, in the tests Drop Vertical Jump (Drop), Single Hop Test (Hop), Triple Hop Test (Triple), Cross-over Hop Test (Cross), Six-Meter Timed Hop Test (6M) e Sidestep Cutting (Sid), through rotation and knee angular speed kinematic analysis, and by the low member muscles co-activation, in female handball players. The experimental research design was a cross-sectional in which were evaluate 12 participants in the average age of 21.2±2.4, average body mass of 68.9±10.3kg and average height of 1.70±0.04m. Before the evaluation all made a 5 minutes warm-up and marked with 25 reflective markers in bony prominences of interest for further kinematic analysis. Besides that, where attached 10 electromyography sensors (EMG TrignoTM Wireless System), recto-femoral muscles, femoral biceps and gluteus medium. After the volunteer preparation where evaluated the six functional tests Drop, Hop, Triple, Cross, 6M and Sidestep Cutting in three valid attempts with the dominant limb. The kinematic data where obtained by the movement capture system VICON (Centennial, CO, EUA) and analyzed by the developed routines using the software MatLab (Mathworks Inc., Natick, MA, USA). The knee rotation angle, specifically the knee valgus, where generated by the sequences of Euler rotation angle. The scalar angular speeds where drawn by unitary quaternion. Finally, the co-activation ratios between the recto-femoral/femoral biceps (RB) and recto-femoral/gluteus medium (RG) where normalized integral sign by EMG. From this where set the variables moments in each evaluated test. To the valgus angle where extracted the initial contact values (CI) through a force platform (Columbus, EUA), 40ms and 100ms after the CI, in maximum flexion (Flexmax) and maximum knee valgus (Valgomax). To angular speeds where the same moments plus the positive speed momentum (Velpos) and negative speed momentum (Velneg). To the co-activation where used the same angle moments plus the moment of force peak ground reaction (FPRS). In the valgus angle there was interaction [F(2,220)=11,456; p<0,001] comparing (moment x tests) revealing significant differences in pairwise comparison. In CI, on 100ms and Flexmax the Sid presented difference to all most all the other tests likewise the Drop on Flexmax. In the angular speed there was the interaction [F(30,330)=14,476; p<0,001] with significant differences in pairwise comparison. In the moment 40ms, 100ms, Velpos and Velneg the Drop presented differences to all most all the other tests likewise the 6M pointed differences to all the other 100ms and Velneg tests. There was also a moderated relation from: Cross in the Valgomax moment in valgus angle variables and angle speed (p=0,032); Sid in 40ms moment the valgus angle variables and the co-activation (p=0,015); Hop in 100ms moment the valgus angles variables and co-activation RG (p=0,029). We can conclude that the knee dynamics instability functional tests in the dynamic valgus critical moments analysis, show that the valgus angle variables and angular velocity specific behaviors in the tests applied. Besides that was established that the knee valgus increase in Cross is influenced by the speed of angular velocity. Also can be concluded that the neuromuscular adaptation RB in SID - 40ms, has a direct influence of valgus angle and the synergism of Hop - 100ms, is fundamental to the knee valgus angle control

O objetivo deste trabalho foi avaliar a importância relativa dos diferentes estabilizadores estáticos do canto póstero-lateral do joelho. Para isso foram utilizados 10 joelhos de cadáveres que foram submetidos a testes biomecânicos com a aplicação de forças para a deformação em varo e em rotação externa. Os joelhos foram testados em quatro situações diferentes e sempre na mesma seqüência: com a articulação íntegra, após a secção do ligamento colateral lateral, após a secção do ligamento colateral lateral e do complexo poplíteo-fibular (tendão do poplíteo + ligamento poplíteo-fibular) e após a secção do ligamento colateral lateral, do complexo poplíteo-fibular e da cápsula póstero-lateral. Os testes foram feitos com os joelhos em extensão, em 30 e em 60 graus de flexão. Os parâmetros estudados foram a deformação angular e a rigidez durante a aplicação do momento de flexão (varo) de 15 N.m e do momento de torção (rotação externa) de 6 N.m. A análise estatística foi realizada com o teste de comparações múltiplas de Tukey. Através da análise dos resultados obtidos com os testes biomecânicos e comparando os valores obtidos nas quatro situações estudadas entre si, foi possível interpretar a função específica de cada estrutura do canto póstero-lateral do joelho, em cada ângulo de flexão testado. Neste estudo, o ligamento colateral lateral foi importante na estabilização do joelho para o varo em extensão, em 30 e em 60 graus de flexão. O complexo poplíteo-fibular foi a estrutura mais importante na estabilização do joelho para a rotação externa, dentre as estruturas avaliadas, atuando em todos os ângulos de flexão testados. Além disto, complexo poplíteo-fibular foi importante na estabilização para o varo quando o joelho se encontrava em 30 e em 60 graus de flexão. Já a cápsula póstero-lateral foi importante na estabilização para o varo e para a rotação externa quando o joelho se encontrava em extensão, perdendo sua função à medida que o joelho foi flexionado. Em 30 graus de flexão, a cápsula póstero-lateral foi importante apenas para a estabilização em varo do joelho. / The purpose of this study was to evaluate, in cadaver knees, the relative importance of the different static stabilizers of the posterolateral corner of the knee. Tests were performed with the application of a varus and external rotation force to the knee in extension, 30 and 60 degrees of flexion, using 10 cadaver knees. The forces were applied initially to an intact knee and then repeated after a selective sectioning of the ligaments: section of the lateral collateral ligament; section of the lateral collateral ligament and the popliteofibular complex; and section of the lateral collateral ligament, the popliteofibular complex and the posterolateral capsule. The parameters studied were the angular deformity and rigidity while the knees were being submitted to a 15 newton-meter varus torque and a 6 newton-meter external tibial torque. Statistical analysis was performed using the ANOVA and Tukey tests. Our findings showed that the lateral collateral ligament was important in varus stability at 0, 30 and 60 degrees; the popliteus-fibular complex was the most important structure in external rotation stability at all angles of flexion and was also important for varus stability at 30 and 60 degrees; the posterolateral capsule was important for varus stability at 0 and 30 degrees, and for external rotation stability in extension.