Osteoarthritis of the hip frequently occurs in the absence of osteoarthritis in other large joints, suggesting that local factors are important in its pathogenesis. Hip morphology has been recognised as a potential local biomechanical risk factor for the development of hip osteoarthritis. There are no adequate studies examining osteoarthritis development in the hip. Historical cohorts are either limited by a short follow up or by small numbers. This thesis explores the natural history of hip osteoarthritis in a large population cohort with particular attention to hip morphology as a predictor of osteoarthritis development. Software was developed which allows objective measurements of hip morphology in a reproducible manner. Hip morphology was then measured in a 1000 subject cohort. A detailed description of hip morphology is presented in this thesis, with interesting observations of wide variation and a bimodal distribution for alpha angle (a measure of cam-type femoroacetabular impingement). This is suggestive of a discrete pathological entity, which was associated with osteoarthritis in the cross-sectional analysis. No significant changes exist in terms of morphology during the course of the study and no significant relationship exists between age and hip morphology. Longitudinal analysis of hip morphology with radiographic osteoarthritis and total hip replacement revealed a significant association between cam-type femoroacetabular impingement and acetabular dysplasia with both outcome measures. Measurements of hip morphology were independently predictive of outcome when controlling for baseline age, BMI and joint space width, and significantly increased our ability to predict osteoarthritis and total hip replacement. Similar associations were seen when considering hip pain and symptomatic osteoarthritis as the outcome measures of interest. Pincer-type femoroacetabular impingement was not significantly associated with any of the outcome measures of interest and pain remains relatively poorly explained by both hip morphology and/or radiographic change. The understanding of hip morphology and its role in the natural history of osteoarthritis is significantly improved by this research. Further research is now required to determine whether these morphological abnormalities represent modifiable risk factors for osteoarthritis progression.

Made available in DSpace on 2015-03-26T13:47:26Z (GMT). No. of bitstreams: 1 texto completo.pdf: 330178 bytes, checksum: 0d7d63bcceac97aa987ceb95abd2345a (MD5) Previous issue date: 2003-12-15 / The aim of this study was to evaluate the effects of gallium arsenite (Ga-As) diode laser application on rabbits knees with ostheoarthritis induced by intrarticular injection of carrageenan. Clinical evaluation in vivo showed that there was reduction in inflammatory signs and pain, with treated animals presenting a better performance and greater amplitude of movements, if compared with untreated animals. The degenerative processes resulting from the administration of carrageenan were evidenced in both groups by post-mortem macroscopic and microscopic assessment in both treated and control groups, which allowed inferring that laser diminished the presence of chemical mediators, reducing the inflammatory response and local lesions, including the degradation of glycosaminoglycans. Histological analysis of the synovial membrane revealed the presence of inflammatory cells distributed diffusely or in foci, the intensity of which was higher in control groups. It was concluded therefore that the rate of progression of ostheoarthritis was slowed down by lasertherapy. / O objetivo deste estudo foi avaliar os efeitos do laser a diodo de Arseneto de Gálio (As-Ga) aplicado no joelho de coelhos portadores de osteoartrite induzida pela aplicação intrarticular de carragenina. A avaliação clínica in vivo demonstrou diminuição dos sinais inflamatórios e da dor, permitindo melhor desempenho e maior amplitude de movimento do joelho dos coelhos tratados em comparação aos dos animais não tratados. A avaliação macroscópica e microscópica post-mortem evidenciaram os processos degenerativos decorrentes da administração de carragenina em ambos os grupos, tratado e controle. Os resultados permitiram inferir que o laser diminuiu a presença de mediadores químicos reduzindo, assim, a resposta inflamatória e as lesões locais, inclusive a degradação dos glicosaminoglicanos. A análise histológica da membrana sinovial demonstrou a presença de células inflamatórias, distribuídas difusamente ou em focos, em maior intensidade nos grupos controle. Concluiu-se, portanto, que o caráter progressivo da osteoartrite foi retardado pela laserterapia.