Body structure versus body function in haemophilia: the case of haemophilic ankle arthropathy

Imaging and clinical scores are the main tools used to evaluate the progression of haemophilic arthropathy (HA). Based on haemophilic ankle arthropathy, this study aimed to explore the concordances between structural and clinical alterations, determined by standard radiological and clinical scores, and functional alterations assessed by three-dimensional gait analysis (3DGA). In total, 21 adult haemophilia patients underwent extensive ankle evaluation using the physical examination part of the World Federation of Haemophilia joint score, the Arnold-Hilgartner and the Pettersson radiological scores, and self-reported ankle function assessment using the revised Foot Function Index. Significant associations were found between self-reported ankle function assessment and the three 3DGA variables representative of joint function (range of motion, peak plantar flexion moment, and peak power generated at the push-off phase). Radiological and clinical scores were compared with ankle muscle peak power measurement, the most reliable 3DGA gait variable for ankle function. No significant associations were found between both clinical and functional scores and the 3DGA functional assessment. This discordance may be explained by the lack of a direct relationship between functional alterations detected by 3DGA and the structural changes assessed using X-ray or clinical scoring. Another explanation may be the limitation of clinical and radiological scoring systems in properly determining the severity of HA. Functional assessments such as 3DGA should be used more frequently when monitoring the progression of ankle arthropathy or the effects of therapeutic interventions in adult haemophilia patients.