Changes to Functional Biomechanics and Structure of the Haemophilic Ankle Joint

Haemophilia is a rare disease that causes musculoskeletal bleeds in up to 80% of patients. These bleeds cause arthritic changes to the targeted joint; the aim of the research carried out in this thesis was to investigate the influence of these arthritic changes on the ankle joint. In order to achieve this, longitudinal morphological analysis and finite element studies were carried out on a patient cohort with haemarthropathy of the ankle. Robust, patient specific models were generated in order to carry out novel studies into the influence of features of subchondral bone cysts, such as size, location and depth; and to develop a quasi-dynamic method of modelling patient specific haemophilic gait. The results gathered from these models highlighted the importance of patient specificity in a disease with such variable joint outcomes. Despite a small sample size, and informational constraints, the results of the studies undertaken highlighted structural and functional changes of the haemophilic ankle, and demonstrated potential relationships between the two. Morphological analysis showed a significant flattening of the talus in the medial and lateral regions of the haemophilic ankle. Upon investigation of the link between this morphological variation and consequent joint function, a significant negative correlation between talar collapse and cartilage contact pressure, and bone stresses was found in static modelling; and through the gait cycle the regions of high contact forces related to regions of significant talar collapse.