Identification and long-term observation of early joint damage by magnetic resonance imaging in clinically asymptomatic joints in patients with haemophilia A or B despite prophylaxis.

Severe haemophilia is associated with recurrent joint bleeds, which can lead to haemophilic arthropathy. Subclinical joint bleeds have also been associated with joint damage detected using magnetic resonance imaging (MRI). We investigated the development of early changes in clinically asymptomatic joints using MRI in haemophilia A or B patients receiving prophylactic therapy. In this single-centre retrospective cohort study, patients with clinical evidence of joint damage in one ankle and one clinically asymptomatic ankle, in which we performed an MRI scan of both ankles in one session, were enrolled. MRI findings were graded using a 4-point scoring system (0 = normal findings and III = severe joint damage). Since 2000, 38 MRIs in 26 patients have been performed. Starting at a median age of 4 years, 23 patients received prophylaxis 2-3 times weekly. On-demand treatment was performed in three patients. Eight patients (31%) presented with an MRI score of 0, 12 (46%) had a score of I, four (15%) had a score of II, and two (8%) had a score of III in the clinically unaffected ankle. The six patients with MRI scores of II and III had started regular prophylaxis between the ages of 2 years and 15 years; none had developed an inhibitor or experienced a clinically evident bleed in the asymptomatic ankle. During our study, five of 26 patients had a worsening of MRI findings without experiencing a joint bleed. Early morphological changes in clinically asymptomatic ankles can be detected using MRI, despite adequate prophylaxis.