Hydroxyproline (Hyp), a non-proteinogenic amino acid is a component of the organic material in bone. It has been used for 14C-dating of bone and the measurement of Hyp could be used as a biomarker in bone metabolism. Hydroxyproline is a component of collagen, the main structural protein in bone. The analyses of 14C in collagen and Hyp in human bones may provide timing information about bone processes and diseases, such as osteoarthritis and osteoporosis. The analysis of Hyp in bones (e.g., the determination of Hyp content) primarily relies on a spectrometric technique, liquid chromatography-mass spectrometry (LC-MS), and the determination of 14C content requires accelerator mass spectrometry (AMS). Moreover, to obtain these materials from bone requires the successful extraction of collagen and thr separation of Hyp from the collagen. This study aims at comparing methods for extracting collagen from bone, which do not destroy the Hyp. These methods include the use of either NaOH, KOH or HCl in one stage of the extraction process and separating sufficient Hyp for 14C analysis. This will provide information to determine whether Hyp can be used as a biomarker for bone diseases like osteoarthritis and osteoporosis. A preliminary 14C AMS analysis on collagen extracted by the NaOH method was carried out on human bones previously analyzed for forensic purposes. This demonstrated the ability of this technique to provide recent (post 1950) timing information. The collagen extractions by three different methods were first conducted on modern chicken bone, and the results showed that KOH method is the best bone collagen extraction method, yielding a largest quantity of Hyp. The KOH method was then employed to extract collagen from cow bone as a test of a more human-like (mammalian) material. As this was successful, collagen was extracted from diseased human bone fragments, obtained from the Ottawa Hospital. The data revealed that Hyp was successfully obtained from these bones. The study demonstrates that the extraction as well as the separation methods (preparative HPLC) can provide sufficient Hyp from bones for 14C AMS analysis. This will lead to future studies of Hyp in bone turnover, which may lead to its use as a novel biomarker for bone diseases such as osteoarthritis and osteoporosis.

Osteoarthritis (OA) is a chronic disease that affects the joints, most commonly hands, hips, knees, feet, and spine (Litwic et al. 2013). The disease becomes more common with advanced age and is one of the most prevalent causes of disability in older populations. Currently there is no cure besides total joint replacement surgery, and there will be approximately 4 million Americans living with a hip replacement by the end of the next decade (Maradit Kremers et al. 2015). Osteoarthritis was classically characterized as a disease of progressive articular cartilage degradation, but the degeneration involves all tissues of the synovial joint including the periarticular muscles, joint capsule, synovium, ligaments, and subchondral and metaphyseal bone. The cause of pain in OA is not well understood, but it is known that bone marrow lesions (BMLs) identified in subchondral bone by MRI are an important determinant of pain (Felson et al. 2001; Kumar et al. 2013). Abnormal blood vessel growth may be responsible MRI signature of BMLs, and the commonality between pathways for angiogenesis and neurogenesis suggests this pathologic process may be the source of pain in OA. The objective of this study was to characterize the histologic nature of subchondral cysts identified by micro computed tomography (μCT) which had been registered with MRI images in which marrow lesions were identified. Femoral heads were collected from 10 patients (6 females and 4 females; age 29-80) who underwent total hip arthroplasty. All patients had MRIs performed within 6 months prior to surgery. The heads were fixed and scanned with μCT to identify cysts in the subchondral bone. A block of the femoral head containing the cyst of interest was resected and processed for histologic analysis. The sections were stained with either Safranin-O and Fast Green or hematoxylin and eosin to view the nature and composition of the tissue. A two-dimensional image from the μCT that corresponded to the histologic slice was matched with a coronal view from the MRI. The primary compressive group was reliably identified on μCT images and served as good indicator for orienting the CT to match with the MRI. The subchondral cysts that were matched to MRI all consisted of predominantly fibrous bone marrow and frequently had a large number of blood vessels within the tissue. Three of the eight cysts had cartilage intrusions that were located mostly within peripheral trabecular bone, though one cyst contained a nodule of cartilage surrounded by organized fibers with the texture of granulation tissue. The process of image registration was mostly performed manually, but the development of this process will contribute to a more refined, semi-automated process in the future. The ability to correlate the histopathology of CT-identified lesions with a signature patter on MRI will be an important tool for better characterizing the nature of BMLs and understanding the pathogenesis of OA.

Vários estudos demonstram que a atividade física é capaz de trazer benefícios para as cartilagens articulares. Estes manifestam-se reduzindo os riscos de lesão articular, prevenindo aderências na articulação, aumentando e mantendo sua mobilidade e combatendo a obesidade, grande fator de risco para o desenvolvimento de lesões articulares. Por outro lado, sabe-se que o envelhecimento provoca alterações deletérias em vários tecidos, inclusive nas cartilagens articulares. O objetivo deste trabalho foi verificar se a atividade física regular promove alterações no processo de envelhecimento da cartilagem articular da cabeça do fêmur de ratos Wistar corredores. Para este estudo foram utilizados 24 ratos Wistar corredores, os quais foram divididos em três grupos de oito animais cada: Sedentários (S) - ratos adultos sedentários; Treinados (T) - ratos adultos treinados; e Controle (C) - ratos adultos jovens. As cartilagens articulares das cabeças femorais foram analisadas por dois métodos: microscopia de luz (três de cada grupo) e microscopia eletrônica de varredura (cinco de cada grupo). Os resultados em microscopia de luz foram obtidos a partir do método esteriológico. Os valores não foram estatisticamente diferentes em relação à idade e ao treinamento para os parâmetros: volume total da cartilagem, número total de condrócitos, densidade de volume de matriz e volume total de matriz (P=0,05). Os dados foram significantes em \"border line\" para idade nos parâmetros densidade do volume celular e volume celular indireto (P=0,058) e para treinamento no parâmetro densidade celular (P=0,058). À microscopia eletrônica de varredura foi possível observar que no grupo S a superfície articular da cabeça femoral apresentava-se lisa e com áreas de erosões bem evidentes, enquanto que, no grupo T e C, haviam nítidas ondulações, sem presença de erosões. Estes dados nos levam a concluir que um programa de atividade física constante durante o envelhecimento é benéfico para a cartilagem articular da cabeça do fêmur, pois sugere que a cartilagem dos animais do grupo S foi mais susceptível a lesões do que as do grupo T e C, e que a atividade física promoveu a estimulação dos condrócitos, aumentando, assim, a resistência da cartilagem às modificações deletérias do envelhecimento. / Several studies has demonstrate that the physical activity can bring benefits for the articular cartilage. These show a reduction in articular lesion risks, preventing the adherences in the articulation, increasing and maintaining its mobility and combating the obesity, which is a great risk factor for the development of articulate lesions. On the other hand, it is known that the aging provokes harmful alterations in several tissues, including articular cartilage. The objective of this work was to verify if the regular physical activity promotes alterations in the process of aging of the articular cartilage of the femoral head of Wistar runner rats. For this research were used 24 Wistar runner rats. The animals were divided in three groups containing eight animals each one: Sedentary (S) - adult sedentary rats; (T) - adult trained rats; and Control (C) - young adult rats. The articular cartilages of the femoral heads were analyzed by two methods: light microscopy (three each group) and scanning electron microscopy (five each group). The results in light microscopy were obtained using stereological method and there were not statistically significant differences in relation to age and training for the parameters: total volume of the cartilage, total number of chondrocytes, volume density of extra cellular matrix and total volume of extra cellular matrix (P=0,05). The data were statistically significant in \"border line\" for age in the parameters chondrocyte volume density and mean chondrocyte volume (P=0,058) and for training in the parameter cellular density (P=0,058). By scanning electron microscopy was possible to observe that in S group, the surface of articular cartilage of the femoral head came flat and with areas of evident erosions, while, in T group, there were clear undulations, without the presence of erosions. These data take us to conclude that a program of constant physical activity during the aging promotes benefits for the articular cartilage of the femoral head by suggests that the cartilage of the animals of the S group was more susceptible to lesions than the ones of the T and C group and that the physical activity promoted the stimulation of the chondrocytes, increasing the resistance of the cartilage to the harmful modifications of the aging.

A necrose asséptica da cabeça do fêmur (NACF) em cães é uma doença auto limitante do quadril em desenvolvimento, caracterizada por uma necrose asséptica, seguida por fratura subcondral, fragmentação, revascularização e remodelação na cabeça femoral. A etiologia da doença é obscura. A radiografia é a modalidade de imagem padrão utilizada para diagnosticar a doença em cães. Foi realizado um estudo retrospectivo de janeiro de 2000 até janeiro de 2010 nas radiografias de coxal com NACF nos cães atendidos no Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo. Radiografias com NACF foram reavaliadas e os graus de alterações radiográficas foram correlacionados a raça, sexo, idade, membro(s) acometido(s). Foi estudado também a evolução radiográfica dos pacientes que tinham mais de um exame realizado. Analisando os resultados, observou-se que as três principais raças acometidas foram Poodles, Yorkshires e Pinschers. A NACF acomete principalmente animais jovens e de pequeno porte, porém no estudo houve um animal de grande porte e alguns animais com idade avançada. Não houve uma predisposição sexual. Com relação aos membros acometidos, notou-se que o grau 5 da doença apresenta maior incidência no membro pélvico direito e ao estudar a evolução da NACF, observou-se tratar de uma doença progressiva e de evolução lenta. Foram avaliadas imagens em filme radiográfico e imagens digitalizadas, sendo possível fazer uma comparação entre os dois métodos. Todas as imagens digitalizadas foram encontradas, ao contrário das imagens em filme radiográfico, demonstrando a facilidade e rapidez que a digitalização pode trazer. / Aseptic necrosis of the femoral head (ANFH) in dogs is a self limiting disease of the developing hip, characterized by an aseptic necrosis, followed by subchondral fracture, fragmentation, revascularization and remodeling of the femoral head. The etiology of the disease is unclear. In dogs the standard imaging modality is radiography. A retrospective study from January 2000 to January 2010 of ANFH cases attended at the Veterinary Hospital of the University of Sao Paulo was done. Radiographs of the hips diagnosed with ANFH where reexamined, the degree of changes established correlating data with breed, gender, age, and affected member. The three major breeds involved were Poodles, Yorkshires and Pinschers. The ANFH mainly affects young and small animals, but in this study there was one large animal and some animals with advanced age. There was no sexual predisposition. In the affected limbs, it was noted that the grade 5 of the disease has a higher incidence in the right limb. In patients with more than one examination evolution of the radiographic changes was analyzed. No regression of radiographic changes was registered and ANFH showed to be a progressive disease with slow evolution. To work with conventional and digital images showed no difficulty in reading but a substantial portion of conventional images were not found.

Pacientų, patyrusių šlaunikaulio kaklo lūžius, gydymas – aktuali senstančios visuomenės problema, todėl literatūroje gausu publikacijų, analizuojančių įvairius šios patologijos gydymo aspektus. Analizuojant literatūros duomenis pastebima, kad nėra išskiriamas laikas nuo traumos iki patekimo į ligoninę, o laikas pradedamas skaičiuoti tik nuo tada, kada pacientas jau paguldytas į ligoninę. Šis veiksnys gali turėti reikšmingos įtakos galutiniams gydymo rezultatams, nes laikotarpio nuo traumos iki patekimo į ligoninę trukmė gali labai svyruoti tarp įvairių pacientų grupių. Todėl buvo tikslinga atlikti tyrimą, kuriame būtų įvertintas būtent šis laikotarpis ir nustatyta jo reikšmė pacientų mirštamumui ir funkciniams gydymo rezultatams. Savo darbe tyrėme veiksnius, įtakojančius šlaunikaulio kaklo lūžius patyrusių pacientų mirštamumą ir funkcinius gydymo rezultatus. / Treatment of patients with femoral neck fractures is an important issue in an ageing population; therefore, in the scientific literature, there are a lot of publications analysing various aspects of management of this pathology. However, while analysing the literature data, it was noted that the time from trauma to hospital admission is not taken into account, and the time is being counted just from that moment, when a patient is already hospitalised. This factor may have a great influence on treatment outcome because the time from trauma to hospital admission can vary significantly among different patient’s groups. Therefore, it was purposeful to carry out a study where exactly this period would be evaluated and its influence on patients’ mortality and functional outcome would be determined.

Vários estudos demonstram que a atividade física é capaz de trazer benefícios para as cartilagens articulares. Estes manifestam-se reduzindo os riscos de lesão articular, prevenindo aderências na articulação, aumentando e mantendo sua mobilidade e combatendo a obesidade, grande fator de risco para o desenvolvimento de lesões articulares. Por outro lado, sabe-se que o envelhecimento provoca alterações deletérias em vários tecidos, inclusive nas cartilagens articulares. O objetivo deste trabalho foi verificar se a atividade física regular promove alterações no processo de envelhecimento da cartilagem articular da cabeça do fêmur de ratos Wistar corredores. Para este estudo foram utilizados 24 ratos Wistar corredores, os quais foram divididos em três grupos de oito animais cada: Sedentários (S) - ratos adultos sedentários; Treinados (T) - ratos adultos treinados; e Controle (C) - ratos adultos jovens. As cartilagens articulares das cabeças femorais foram analisadas por dois métodos: microscopia de luz (três de cada grupo) e microscopia eletrônica de varredura (cinco de cada grupo). Os resultados em microscopia de luz foram obtidos a partir do método esteriológico. Os valores não foram estatisticamente diferentes em relação à idade e ao treinamento para os parâmetros: volume total da cartilagem, número total de condrócitos, densidade de volume de matriz e volume total de matriz (P=0,05). Os dados foram significantes em \"border line\" para idade nos parâmetros densidade do volume celular e volume celular indireto (P=0,058) e para treinamento no parâmetro densidade celular (P=0,058). À microscopia eletrônica de varredura foi possível observar que no grupo S a superfície articular da cabeça femoral apresentava-se lisa e com áreas de erosões bem evidentes, enquanto que, no grupo T e C, haviam nítidas ondulações, sem presença de erosões. Estes dados nos levam a concluir que um programa de atividade física constante durante o envelhecimento é benéfico para a cartilagem articular da cabeça do fêmur, pois sugere que a cartilagem dos animais do grupo S foi mais susceptível a lesões do que as do grupo T e C, e que a atividade física promoveu a estimulação dos condrócitos, aumentando, assim, a resistência da cartilagem às modificações deletérias do envelhecimento. / Several studies has demonstrate that the physical activity can bring benefits for the articular cartilage. These show a reduction in articular lesion risks, preventing the adherences in the articulation, increasing and maintaining its mobility and combating the obesity, which is a great risk factor for the development of articulate lesions. On the other hand, it is known that the aging provokes harmful alterations in several tissues, including articular cartilage. The objective of this work was to verify if the regular physical activity promotes alterations in the process of aging of the articular cartilage of the femoral head of Wistar runner rats. For this research were used 24 Wistar runner rats. The animals were divided in three groups containing eight animals each one: Sedentary (S) - adult sedentary rats; (T) - adult trained rats; and Control (C) - young adult rats. The articular cartilages of the femoral heads were analyzed by two methods: light microscopy (three each group) and scanning electron microscopy (five each group). The results in light microscopy were obtained using stereological method and there were not statistically significant differences in relation to age and training for the parameters: total volume of the cartilage, total number of chondrocytes, volume density of extra cellular matrix and total volume of extra cellular matrix (P=0,05). The data were statistically significant in \"border line\" for age in the parameters chondrocyte volume density and mean chondrocyte volume (P=0,058) and for training in the parameter cellular density (P=0,058). By scanning electron microscopy was possible to observe that in S group, the surface of articular cartilage of the femoral head came flat and with areas of evident erosions, while, in T group, there were clear undulations, without the presence of erosions. These data take us to conclude that a program of constant physical activity during the aging promotes benefits for the articular cartilage of the femoral head by suggests that the cartilage of the animals of the S group was more susceptible to lesions than the ones of the T and C group and that the physical activity promoted the stimulation of the chondrocytes, increasing the resistance of the cartilage to the harmful modifications of the aging.

A necrose asséptica da cabeça do fêmur (NACF) em cães é uma doença auto limitante do quadril em desenvolvimento, caracterizada por uma necrose asséptica, seguida por fratura subcondral, fragmentação, revascularização e remodelação na cabeça femoral. A etiologia da doença é obscura. A radiografia é a modalidade de imagem padrão utilizada para diagnosticar a doença em cães. Foi realizado um estudo retrospectivo de janeiro de 2000 até janeiro de 2010 nas radiografias de coxal com NACF nos cães atendidos no Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo. Radiografias com NACF foram reavaliadas e os graus de alterações radiográficas foram correlacionados a raça, sexo, idade, membro(s) acometido(s). Foi estudado também a evolução radiográfica dos pacientes que tinham mais de um exame realizado. Analisando os resultados, observou-se que as três principais raças acometidas foram Poodles, Yorkshires e Pinschers. A NACF acomete principalmente animais jovens e de pequeno porte, porém no estudo houve um animal de grande porte e alguns animais com idade avançada. Não houve uma predisposição sexual. Com relação aos membros acometidos, notou-se que o grau 5 da doença apresenta maior incidência no membro pélvico direito e ao estudar a evolução da NACF, observou-se tratar de uma doença progressiva e de evolução lenta. Foram avaliadas imagens em filme radiográfico e imagens digitalizadas, sendo possível fazer uma comparação entre os dois métodos. Todas as imagens digitalizadas foram encontradas, ao contrário das imagens em filme radiográfico, demonstrando a facilidade e rapidez que a digitalização pode trazer. / Aseptic necrosis of the femoral head (ANFH) in dogs is a self limiting disease of the developing hip, characterized by an aseptic necrosis, followed by subchondral fracture, fragmentation, revascularization and remodeling of the femoral head. The etiology of the disease is unclear. In dogs the standard imaging modality is radiography. A retrospective study from January 2000 to January 2010 of ANFH cases attended at the Veterinary Hospital of the University of Sao Paulo was done. Radiographs of the hips diagnosed with ANFH where reexamined, the degree of changes established correlating data with breed, gender, age, and affected member. The three major breeds involved were Poodles, Yorkshires and Pinschers. The ANFH mainly affects young and small animals, but in this study there was one large animal and some animals with advanced age. There was no sexual predisposition. In the affected limbs, it was noted that the grade 5 of the disease has a higher incidence in the right limb. In patients with more than one examination evolution of the radiographic changes was analyzed. No regression of radiographic changes was registered and ANFH showed to be a progressive disease with slow evolution. To work with conventional and digital images showed no difficulty in reading but a substantial portion of conventional images were not found.

Hip resurfacing is an alternative to total hip arthroplasty for the young and active patient likely to outlive traditional means of hip joint replacement. The acetabular cup is implanted in much the same fashion as an uncemented total hip arthroplasty, however, implantation of the femoral component is unique to hip resurfacing, presenting both distinct benefits and limitations. Hip resurfacing spares much of the proximal femur including the femoral neck and portions of the femoral head. This may be advantageous if the patient requires revision surgery; however, preservation of the femoral neck bears with it the risk of femoral neck fracture. The exact mechanism of neck fracture is not fully understood. Avoiding potential fracture risks is vital to ensuring optimal patient outcomes. The current work investigated mechanical femoral head preparatory factors that may predispose to femoral neck fracture. Intra-operative computer navigation is emerging as the gold-standard in orthopaedic care. In hip resurfacing, navigation may improve the surgeon’s ability to optimally implant the resurfacing prosthesis; however, much of this technology is still in its infancy and requires investigation into the accuracy and repeatability of this peri-operative tool. Pre-operative planning can assist the surgeon in optimally determining the size and position of the resurfacing components, specifically in reference to the patient’s unique anatomy, prior to performing the operation. This may aid in correct implant selection and provide a basis on which to conduct intra-operative navigation. However, the accuracy and repeatability of pre-operative planning for hip resurfacing has not yet been established. Thus, this body of work looked to establish a clear methodology for pre-operative planning, intra-operative computer navigation and surgical technique in order to optimize preparation of the femoral head, ultimately reducing the risk of femoral neck fracture in hip resurfacing.

Hip resurfacing is an alternative to total hip arthroplasty for the young and active patient likely to outlive traditional means of hip joint replacement. The acetabular cup is implanted in much the same fashion as an uncemented total hip arthroplasty, however, implantation of the femoral component is unique to hip resurfacing, presenting both distinct benefits and limitations. Hip resurfacing spares much of the proximal femur including the femoral neck and portions of the femoral head. This may be advantageous if the patient requires revision surgery; however, preservation of the femoral neck bears with it the risk of femoral neck fracture. The exact mechanism of neck fracture is not fully understood. Avoiding potential fracture risks is vital to ensuring optimal patient outcomes. The current work investigated mechanical femoral head preparatory factors that may predispose to femoral neck fracture. Intra-operative computer navigation is emerging as the gold-standard in orthopaedic care. In hip resurfacing, navigation may improve the surgeon’s ability to optimally implant the resurfacing prosthesis; however, much of this technology is still in its infancy and requires investigation into the accuracy and repeatability of this peri-operative tool. Pre-operative planning can assist the surgeon in optimally determining the size and position of the resurfacing components, specifically in reference to the patient’s unique anatomy, prior to performing the operation. This may aid in correct implant selection and provide a basis on which to conduct intra-operative navigation. However, the accuracy and repeatability of pre-operative planning for hip resurfacing has not yet been established. Thus, this body of work looked to establish a clear methodology for pre-operative planning, intra-operative computer navigation and surgical technique in order to optimize preparation of the femoral head, ultimately reducing the risk of femoral neck fracture in hip resurfacing.

Dans le cadre de ce travail de thèse nous nous sommes intéressés à deux pathologies fémoro-acétabulaires dont la pathogénie semble liée aux « conditions biomécaniques » locales. La première partie de cette thèse était consacrée à l’analyse de l’influence de l’anatomie osseuse sur l’apparition de l’ostéonécrose aseptique de la tête fémorale. Nous avons réalisé des analyses analytique de l’anatomie des patients souffrant d’ONA (notre hypothèse était que nous retrouverions un profil anatomique particulier chez les patients souffrant d’ONA par rapport à la population générale.Nos résultats démontrent que les patients souffrant d’ONA présentent fréquemment une anatomie particulière. Notre modèle en éléments finis de la hanche de dix patients souffrant d’ONAi, a permis de valider notre hypothèse puisqu’il existe un recouvrement quasi-parfait, entre la zone de nécrose osseuse et celle supportant les contraintes fémoro-acétabulaires. L’hypothèse selon laquelle une pathogénie mécanique puisse être responsable du développement l’ostéonécrose aseptique de la tête fémorale est vérifiée par nos travaux.Dans la seconde partie de cette thèse nous avons décrit le rôle mécanique du LA par une évaluation multimodale combinant analyse cinématique,de contraintes fémoro-labrales et enfin analyse en éléments finis. Les résultats de ces études ont permis de constater que le LA se déforme lors du mouvement reflétant une transmission de contraintes fémoro-labrales lors du mouvement d’abduction. Ces contraintes ont pu être enregistrées à l’aide de capteurs piezo-resistifs, elles augmentent lors du mouvement d’abduction. Ces éléments ont été confirmés par notre modèle en éléments finis. / As parts of this thesis we focused on two femoro-acetabular diseases whose pathogenesis appears to be related to "biomechanical local conditions". The first part of this thesis was devoted to analyze the influence of bony anatomy on the development of aseptic osteonecrosis of the femoral head. We thus aimed to analyze ONA patients’ anatomy in a matched-controlled fashioned study. Our results demonstrate that patients with ONA often present a particular anatomy. A finite element model of ten iONA hips validated our hypothesis since we found an overlap between bone necrosis area and femoro-acetabular strains bearing area. The assumption that a mechanical pathogenesis may be responsible for ONA development has been confirmed by our results.If the relationship between bony anatomy and bone disease is quite intuitive, acetabular labrum involvement (AL) in the regulation of femoro-acetabular mechanical conditions is unclear. The mechanical role of the AL is widely controversial, though some authors attributed, AL, a key role in hip joint’s mechanics, others advocated its complete resection in case of painful traumatic tears. We tried to demonstrate AL’s mechanical role in a multimodal analysis combining kinematic, strains and finite element analysis. The AL deforms during abduction movement reflecting femoro-labral strains’ transmission. Those strains have been recorded using piezo-resistive sensors, they increase during adduction to abduction movement. These elements were confirmed by our finite element model: labral resection changed the Femoro-acetabular strains to the detriment of cartilage surfaces.