Anteromedial osteoarthritis of the knee (AMOA) has been defined anatomically, histologically and radiologically and yet little is known about the epidemiology of the disease or the risk factors involved in the development of the disease. The broad aim of this thesis was to combine clinical insight with the utilisation of modern, large epidemiological datasets to provide information to inform better the clinical management of patients with AMOA. Specifically, the prevalence and incidence of AMOA, the time taken to progress from early disease to severe disease that may require surgical intervention, the radiological characterisation of disease and the assessment of mechanical risk factors implicit in the development of this pattern of disease are investigated. A cross-sectional study of the radiological prevalence of AMOA in a symptomatic cohort in a specialist secondary care knee clinic showed that AMOA was the commonest pattern of knee OA, present in more than 60% of symptomatic subjects. Less than 25% of subjects with AMOA presented with advanced or 'bone-on-bone' disease, emphasising the clinical importance of understanding the progression from earlier stages of disease to this advanced stage. A 20-year longitudinal radiographic study was performed on 1000 women to describe the prevalence, incidence and progression of AMOA. The prevalence of AMOA was 43% and the incidence over 20-years was 0.4. Life table analysis showed that the risk of developing advanced AMOA in a previously normal knee was 2.6%. Of those subjects with early radiological AMOA, 11% progressed to advanced 'bone-on-bone' disease within 10 years and 37% within 20 years. The role of mechanical risk factors in the development of AMOA showed that both anatomical limb and proximal tibial alignment were significantly more varus aligned in those that developed AMOA at 20-years. Assessment of the shape of the medial tibial plateau in a longitudinal MRI study showed that the angle of the upslope at the anterior aspect of the plateau was significantly increased in the group that subsequently developed AMOA. To enable AMOA to be studies in future MRI studies, the MRI description of the disease was defined. In summary, AMOA was shown to be the most common pattern of knee OA both in symptomatic surgical cohorts and in the community. The progression of the disease from an early stage to an advanced stage, which may require surgical intervention, was described for the first time. To enable better the recognition of AMOA in modern epidemiological studies, the MRI description of AMOA was defined and the clinical relevance of modern MRI was discussed. The anatomical alignment of the limb, the alignment of the proximal tibia and the morphology of the tibial plateau were all shown to have a role in the development of AMOA. Addressing these mechanical factors may provide a therapeutic surgical target for the management of patients with AMOA.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:658495 |
| Date | January 2014 |
| Creators | Bottomley, Nicholas J. |
| Contributors | Price, Andrew; Beard, David |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:34c87265-bbae-4018-b120-ef1d6bed73aa |
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