Background: Hip fractures are a major health problem in Canada, and two main contributors to hip fracture are weak bone strength and fall. Weak muscles also negatively affect bone strength and increase the likelihood of falling. Advanced imaging techniques, such as magnetic resonance imaging (MRI), offer in vivo measurement of bone strength and muscle area at the proximal femur. However, it is not known if MRI-based measurements of bone and muscle properties are repeatable (i.e. precise). Methods: The femoral neck and shaft of 14 healthy participants were scanned three times, using a 1.5T MRI with repositioning between scans. Boundaries of the femoral neck, shaft and four muscle groups were delineated semi-automatically. Geometrical and strength properties of bone and area of muscle groups were determined based on segmented images. The short-term precision errors (root mean square coefficient of variation; CVrms%) between the repeated measures were calculated accordingly. Results: MRI-based measures of bone geometry and strength and muscle area at the proximal femur demonstrated in vivo precision errors < 7.6%. The average CVrms% for bone measures and muscle area were less than 4% and 2.5% respectively. Higher CVrms% (e.g. average: 4.8%) was obtained for bone strength properties. Conclusion: This is the first study to evaluate the in vivo performance of MRI on application to the proximal femur and surrounding muscles. Results demonstrate that MRI is a promising non-ionizing technique that offers precise measures of bone and muscle at the proximal femur.

An intramedullary nail is a trauma treatment device used for fracture fixation of long bones. These devices are subject to failure, including lag screw cut-out and failure at the lag screw insertion hole from high stress concentrations in that region. Clinical developments for such devices are frequently based on a trial and error method, which often results in failure before improvement. However, the finite element method can be used for the development of trauma treatment devices, and their interaction with bone, by providing a large data set at a relatively low cost. Also, parameters can be changed to assess the relative benefits of one device to another. A novel finite element model has been developed that can be used for the analysis of intramedullary nails inserted into long bones. A commercially available finite element package, ANSYS, has been used to implement the modelling strategy. The finite element modelling technique has been applied to fractures of the proximal femur, but the model is generic, and can be developed to deal with any form of intramedullary device where contact between the bone and implant is important. The finite element strategy can be used in pre-clinical trials to test a new device, or for the design optimisation of existing devices. The finite element model consists of the device surrounded by a thin layer of bone, which forms a 'base' model component that is re-usable. This 'base' component can be mathematically connected to any long bone model, forming an integrated implant and bone construct. The construct can be used to assess which device is best suited to a particular fracture, for example. Contact elements have been used to allow stresses to develop as contact is achieved within the implant and bone construct. Pre-assignment of contact points is not required. Verification of the finite element model is achieved by comparison to available data from experiments carried out on constructs of bone and device that use intramedullary femoral nails. In this thesis the finite element model has been applied to two areas of proximal femoral nailing. The finite element model is used to analyse the distal end of a Gamma nail, and shows that analyses that do not consider contact may not lead to accurate predictions of stresses. The model has been developed for using configurations with one and two distal locking screws. The most distal locking screw is more critical under axial loading, and the more proximal screw is more important for bending loads. The use of 'softer' screws distributes the load more evenly between them. The finite element model has been used to investigate the mechanical environment of a fracture callus for a femoral neck fracture, and a subtrochanteric fracture. The use of one and two lag screws, fracture gap size and material properties of the nail have been investigated for a stiffening callus. Results show that the use of two lag screws for a neck fracture provides a more rigid support at the early stages of fracture healing, and minimises stress-shielding once the callus has healed. For subtrochanteric fractures there is a critical point at which the fracture callus is able to carry any load. A Titanium nail significantly reduces the peak stress at the lag screw insertion hole, and titanium lag screws share the load more evenly between them. Each two-lag-screw configuration used transfers a similar load into the fracture callus. A configuration using a larger lag screw above a smaller has a significantly higher stress at the upper lag screw insertion hole. Critically, the load shared between two lag screws changes as the fracture callus stiffens and an assessment should be made at different stages of fracture healing to optimise the use of a device.

No description available.

Sarcoma cancer of the proximal femur is a bone tumor that develops near the hip joint. The most common method of treatment is limb salvage surgery (LLS), a highly invasive surgery that often leads to impaired movement including walking due to soft tissue resection. The current thesis focuses on 1) systematically reviewing current literature of functional outcomes after proximal femur LSS to determine if specific methods of muscle reattachment lead to better limb function, and 2) objectively analysing how reducing hip muscle strength impacts one’s ability to achieve healthy gait. Findings from the systematic review suggest using artificial mesh or ligaments for LLS may be a good alternative to allograft prosthesis composites and trochanter osteotomy, producing good functional outcomes with low rates of complications. It was also determined current literature is lacking objective quantitative analysis of patients’ limb function after surgery. Objective 2 was executed using instrumented gait analysis to record the gait kinematics, kinetics and EMG patterns of a patient who received LSS for proximal femur sarcoma. Data from the gait analysis was used to create a patient-specific musculoskeletal model. Healthy gait kinematics were applied to the model and specific hip muscle strengths were systematically reduced to simulate different surgical interventions. After an 85% reduction in gluteus medius and minimus muscle strength, healthy gait kinematics were not achieved. Reducing muscle strength of the gluteus medius and minimus together had a greater impact on the model’s ability to achieve healthy gait kinematics then when reduced individually. An understanding of how patient’s limb function is impacted after surgery can inform surgical technique, implant design and physiotherapy programs leading to better quality of life for patients after surgery. / Thesis / Master of Applied Science (MASc) / Hip reconstructive surgery as treatment for bone cancer is a highly invasive surgery that negatively impacts patients walking patterns and ultimately quality of life. The current thesis investigates existing literature to determine if specific, innovative surgical techniques lead to better functional results for patients after surgery. A three-dimensional model of a patient who had hip reconstruction surgery for bone cancer was created using quantitative analysis of their walking patterns. The model was manipulated to simulate surgical intervention for hip cancer treatment. The model findings suggest when specific hip muscles are substantially affected by surgery, patients walking patterns are negatively impacted. Understanding how surgical intervention impacts walking patterns can inform surgical technique, implant design and physiotherapy programs leading to better quality of life for patients after surgery.

Due to the demographic development osteopoorosis is an increasing serious medical and economical problem today in developed industrial countries including Czech republic. Fractures of the proximal femur in the elderly are one of the manifestations of the illness. Within the context of the pharmacological prevention we must consider carefully its contribution in comparison with costs of the fracture treatment in the hospital. This graduation theses deals with evaluation of expenses on the surgical treatment of these fractures and expenses on the pharmacological prevention using Fosamax. This comparison is made in economic situation in Czech republic in the end of the first decade of 21. century

As fraturas do fêmur proximal são frequentes em idosos, consideradas uma devastadora consequência da osteoporose, acometem mais o sexo feminino, estão comumente associadas a traumas de pequena energia e, embora apresentem poucas complicações referentes a consolidação no caso das fraturas extracapsulares, estão relacionadas a déficits funcionais, a elevadas taxas de morbidade e mortalidade, além dos altos custos aos serviços de saúde. Representam importante problema de saúde pública mundial devido a sua alta incidência. Trata-se de um estudo retrospectivo com base em um levantamento de prontuários, objetivando caracterizar os pacientes com fraturas do fêmur proximal atendidos na Santa Casa de Misericórdia de Batatais SP. Foram analisados 258 prontuários, de 258 pacientes, correspondendo a 260 fraturas do fêmur proximal (duas fraturas bilaterais) de indivíduos atendidos na Santa Casa de Misericórdia de Batatais no período de janeiro de 2007 a dezembro de 2010 com idade média de 74,8 anos, com predomínio de fraturas na faixa etária entre 80 e 89 anos (35,8%), mulheres (64,6%) e que se declaravam brancos (73%). As fraturas trocantéricas foram as mais incidentes com 60% dos casos, o mecanismo de trauma mais comum foi a queda da própria altura com 91,1% e o lado mais acometido foi o direito com 51,9%. O tratamento cirúrgico foi aplicado a 95,7% das fraturas do fêmur proximal. Dos 258 pacientes incluídos no estudo, 50 foram a óbito, sendo frequente entre as mulheres (61,6%) e o período mais incidente foi com três meses após a fratura. / Proximal femur fractures (PFFs) are common among the elderly. Rendered as a devastating consequence of osteoporosis, women are the most affected. PFFs are commonly associated with low-energy traumas, and, although they have few complications related to consolidation in the case of extracapsular fractures, they are related to functional deficits, high morbidity and mortality rates, besides being costly to health services. Due to the high incidence, PFFs are considered a relevant global public health issue. This is a retrospective study based on a survey of patient records with the objective to characterize the patients with proximal femur fractures seen at the Santa Casa de Misericórdia de Batatais Hospital São Paulo. A total of 258 patient records were analyzed, corresponding to 260 proximal femur fractures (two bilateral fractures) of individuals seen at Santa Casa de Misericórdia de Batatais between January of 2007 and December 2010. Most subjects were women (64.6%) with a mean age of 74.8 years, most in the age group between 80 and 89 years (35.8%), and self-declared being white (73%). Trochanteric fractures were the most common, with 60% of cases. The most common trauma mechanism was falling from ones own height with 91.1%, and the most affected side was the right side with 51.9%. Surgery was the chosen treatment in 95.7% of the proximal femur fractures. Of all the 258 study patients, 50 died, mostly women (61.6%), and the most incident time was at three months after the fracture.

As fraturas do fêmur proximal são frequentes em idosos, consideradas uma devastadora consequência da osteoporose, acometem mais o sexo feminino, estão comumente associadas a traumas de pequena energia e, embora apresentem poucas complicações referentes a consolidação no caso das fraturas extracapsulares, estão relacionadas a déficits funcionais, a elevadas taxas de morbidade e mortalidade, além dos altos custos aos serviços de saúde. Representam importante problema de saúde pública mundial devido a sua alta incidência. Trata-se de um estudo retrospectivo com base em um levantamento de prontuários, objetivando caracterizar os pacientes com fraturas do fêmur proximal atendidos na Santa Casa de Misericórdia de Batatais SP. Foram analisados 258 prontuários, de 258 pacientes, correspondendo a 260 fraturas do fêmur proximal (duas fraturas bilaterais) de indivíduos atendidos na Santa Casa de Misericórdia de Batatais no período de janeiro de 2007 a dezembro de 2010 com idade média de 74,8 anos, com predomínio de fraturas na faixa etária entre 80 e 89 anos (35,8%), mulheres (64,6%) e que se declaravam brancos (73%). As fraturas trocantéricas foram as mais incidentes com 60% dos casos, o mecanismo de trauma mais comum foi a queda da própria altura com 91,1% e o lado mais acometido foi o direito com 51,9%. O tratamento cirúrgico foi aplicado a 95,7% das fraturas do fêmur proximal. Dos 258 pacientes incluídos no estudo, 50 foram a óbito, sendo frequente entre as mulheres (61,6%) e o período mais incidente foi com três meses após a fratura. / Proximal femur fractures (PFFs) are common among the elderly. Rendered as a devastating consequence of osteoporosis, women are the most affected. PFFs are commonly associated with low-energy traumas, and, although they have few complications related to consolidation in the case of extracapsular fractures, they are related to functional deficits, high morbidity and mortality rates, besides being costly to health services. Due to the high incidence, PFFs are considered a relevant global public health issue. This is a retrospective study based on a survey of patient records with the objective to characterize the patients with proximal femur fractures seen at the Santa Casa de Misericórdia de Batatais Hospital São Paulo. A total of 258 patient records were analyzed, corresponding to 260 proximal femur fractures (two bilateral fractures) of individuals seen at Santa Casa de Misericórdia de Batatais between January of 2007 and December 2010. Most subjects were women (64.6%) with a mean age of 74.8 years, most in the age group between 80 and 89 years (35.8%), and self-declared being white (73%). Trochanteric fractures were the most common, with 60% of cases. The most common trauma mechanism was falling from ones own height with 91.1%, and the most affected side was the right side with 51.9%. Surgery was the chosen treatment in 95.7% of the proximal femur fractures. Of all the 258 study patients, 50 died, mostly women (61.6%), and the most incident time was at three months after the fracture.

Diese retrospektive Studie untersucht 351 Patienten mit 358 proximalen Femurfrakturen, die zwischen 01/2008 und 12/2010 im Universitätsklinikum Göttingen behandelt wurden. Ziel war es, das Patientengut mit proximalen Femurfrakturen zu analysieren und Einflüsse der Versorgung sowie der Komorbiditäten auf die Komplikationen und das Outcome der Patienten herauszufinden. Alter und Geschlechterverteilung in diesem Patientengut entsprechen weitgehend den in der Literatur publizierten Angaben. Auffallend ist in dieser Untersuchung, dass Raucher und ehemalige Raucher zum Zeitpunkt der Fraktur signifikant jünger waren als Nichtraucher. Ebenso waren alkoholabhängige und ehemals alkoholabhängige Patienten signifikant jünger als Patienten, die keinen Alkoholabusus betrieben. Die Aussagekraft dieser Ergebnisse wird jedoch durch die geringen Fallzahlen der hier angesprochenen Teilgruppen gemindert. Dennoch ist ein Zusammenhang zwischen Rauchen/Alkoholkonsum und einer in jüngerem Lebensalter auftretenden Fraktur wahrscheinlich. Die höchste Krankenhausliegedauer wiesen Patienten nach H-TEP-Implantation sowie nach Schraubenosteosynthesen auf. Am kürzesten lagen Patienten nach DHS-Implantation. Bezogen auf das Alter zeigten im Gesamtpatientengut die 70-79-jährigen Patienten die längste Krankenhausaufenthaltsdauer. Hinsichtlich der Osteoporosetherapie muss nach den Ergebnissen dieser Studie von einer Minderversorgung in Diagnostik und Therapie ausgegangen werden. Postoperativ stieg der prozentuale Anteil entsprechend therapierter Patienten zwar leicht an, gemessen am Alter und dem Wissen über das Vorkommen von osteoporotischen Frakturen muss aber davon ausgegangen werden, dass bei deutlich mehr Patienten eine Antiosteoporosemedikation dringend notwendig wäre. Die häufigsten medizinischen Komplikationen waren Anämien, Elektrolytentgleisungen und Durchgangssyndrome. Die häufigsten chirurgischen Komplikationen waren Hämatome und Wundheilungsstörungen, gefolgt von mechanischen Komplikationen und Infektionen. Ein Zusammenhang zwischen Hämatomen, Wundheilungsstörungen und Infektionen mit einer präoperativen Antikoagulantientherapie konnte nicht festgestellt werden. Patienten mit Wundinfektionen waren multimorbider als das Gesamtpatientenkollektiv. Eine Zunahme der Komplikationsrate mit dem Alter konnte in dieser Untersuchung nicht nachgewiesen werden. Patienten mit chirurgischen Komplikationen waren geringfügig jünger als die Gesamtgruppe. Bei der Versorgung von Schenkelhalsfrakturen erwiesen sich die Osteosynthesen anfälliger 71 gegenüber chirurgischen Komplikationen als Endoprothesen. Pertrochantäre Frakturen hatten eine erhöhte chirurgische Komplikationsrate bei der DHS im Vergleich zu intramedullären Nagelsystemen. Zeitnah nach der Aufnahme operierte Patienten waren jünger als spät operierte Patienten. Je später der Operationszeitpunkt, desto höher war die ASA-Einstufung. Entsprechend nahmen später als 24 Stunden und innerhalb von sechs bis 24 Stunden operierte Patienten mehr Medikamente ein als die innerhalb von sechs Stunden operierten Patienten. Die später als 24 Stunden Operierten lagen deutlich länger im Krankenhaus als die früher Operierten. Hinsichtlich des Auftretens von postoperativen Komplikationen konnte kein Zusammenhang mit dem Operationszeitpunkt festgestellt werden. Die im Krankenhaus verstorbenen Patienten wiesen eine im Vergleich zur Gesamtgruppe leicht erhöhte präoperative Verweildauer auf, aufgrund der geringen Fallzahlen ist die Aussagekraft aber gemindert. Die Verstorbenen waren nicht älter als das Gesamtpatientengut. Gemessen an der Anwendungshäufigkeit der Therapiemittel wiesen Patienten mit Endoprothesen eine höhere Letalität auf. Häufig waren Hochrasanz- oder Absturztraumen Unfallursache. Die verstorbenen Patienten, die durch einen banalen Sturz die Fraktur erlitten, waren multimorbider als die Gesamtgruppe.

Osteoarthritis (OA) is the most common form of human joint disease causing significant pain and disability. Current treatment for hip OA is limited to pain management and joint replacement for end-stage disease. The development of methods for early diagnosis and new treatment options are urgently needed to minimise the impact of the disease. Studies of hip OA have shown that hip joint morphology correlates with susceptibility to hip OA and disease progression. Bone shape analyses play an important role in disease diagnosis, pre-operative planning, and treatment analysis as well as in epidemiological studies aimed at identifying risk factors for hip OA. Statistical Shape Models (SSMs) are being increasingly applied to imaging-based bone shape analyses as they provide a means of quantitatively describing the global shape of the bone. This is in contrast to conventional clinical and research practice where the analysis of bone shape is reduced to a series of measurements of lengths and angles. This thesis describes the development of a novel fully automatic software system that segments the proximal femur from anteroposterior (AP) pelvic radiographs by densely placing 65 points along its contour. These annotations can then be used for the detailed morphometric analysis of proximal femur shape. The performance of the system was evaluated on a large dataset of 839 radiographs of mixed quality. Achieving a mean point-to-curve error of less than 0.9mm for 99% of all 839 AP pelvic radiographs, this is the most accurate and robust automatic method for segmenting the proximal femur in two-dimensional radiographs yet published. The system was also applied to a number of morphometric analyses of the proximal femur, showing that SSM-based radiographic proximal femur shape significantly differs between males and females, and is highly symmetric between the left and right hip joint of an individual. In addition, the research described in this thesis demonstrates how the point annotations resulting from the system can be used for univariate and multivariate genetic association analyses, identifying three novel genetic variants that contribute to radiographic proximal femur shape while also showing an association with hip OA.The developed system will facilitate complex morphometric and genetic analyses of shape variation of the proximal femur across large datasets, paving the way for the development of new options to diagnose, treat and prevent hip OA.

Osteoarthritis (OA) is a chronic, painful, and currently incurable disease characterized by structural deterioration and loss of function of synovial joints. OA is known to involve profound changes in bone density and microstructure near to, and even distal to, the joint. The prevailing view is that these changes in density and microstructure serve to stiffen the subchondral region thereby altering the mechanical environment (stresses and strains) within the epiphyseal and metaphyseal bone, and that these alterations trigger the aberrant cellular signaling and tissue damage characteristic of the progression of OA. Critically, however, these alterations in mechanical environment have never been well documented in a quantitative fashion in hip OA. Separately, although OA is generally thought to be inversely associated with fragility fracture, recent data challenge this idea and suggest that OA may actually modulate which regions of the proximal femur are at risk of fracture. Therefore, the goal of this work was to provide a spatial assessment of bone density and microstructure in hip OA and then examine the mechanical consequences of these OA-related abnormalities throughout the proximal femur. First, micro-computed tomography and data-driven computational anatomy were used to examine 3-D maps of the distribution of bone density and microstructure in human femoral neck samples with increasing severity of radiographic OA, providing evidence of the heterogeneous and multi-faceted changes in hip OA and discussion of the implications for OA progression and fracture risk. Second, the feasibility of proton density-weighted MRI in image-based finite element (FE) modeling, to examine stress, strain, and risk of failure in the proximal femur under sideways fall, was assessed by comparison to the current standard of CT-based FE modeling. Third, phantom-less calibration for CT-based FE modeling was used with clinically available pre-operative patient scans to assess bone strength and failure risk of the proximal femur in hip OA. Overall, the results of this work provide a rich, quantitative definition of the ways in which the bone mechanical environment under traumatic loading differ in association with hip OA, and then highlight the potential for clinical image-based FE methods to be used opportunistically to assess bone strength and failure risk at the hip. This work is significant because it directly tests the long-standing premise that OA is associated with changes in the mechanical environment of the bone tissue in ways that are impactful for OA progression; further, this work examines how these changes may influence risk of hip fracture. The results can be used to identify mechanistic predictors of OA progression, to inform development of bone-targeting treatments for OA, and to more broadly understand bone damage and fracture in this population.