Magnetic resonance imaging and ultrasound evaluation of "healthy" joints in young subjects with severe haemophilia A

Magnetic resonance imaging (MRI) and ultrasonography (US) are increasingly used in haemophilia A (HA) to detect early joint changes. A total of 40 clinically asymptomatic joints, never involved by bleeding events [healthy joints (HJ)], were evaluated by MRI and, in parallel, by US in 20 young subjects with severe HA (22.45 +/- 2.72years old; no history of arthritides, of viral infections or of inhibitors against factor VIII). The same joints were evaluated in 20 matched non-haemophilic (no-HA) subjects (mean age 23.90 +/- 2.31years, P=0.078 vs. HA subjects). US images were obtained with specific probe positions according to validated procedures. A validated US score and progressive (P-MRI) and additive (A-MRI) MRI scores were employed for data collection and analysis. The US score was higher in HA than in no-HA subjects (3.40 +/- 1.72 vs. 0.80 +/- 1.10, P<0.001). Taking into account only moderate/severe alterations, joint effusion was found in 55% of HA and in 5% of no-HA joints (P<0.001); synovial hypertrophy was found in 20% of HA and in none of the no-HA joints; cartilage erosion was found in 30% of HA and in none of no-HA joints. MRI examinations confirmed these findings and the US score correlated with the A-MRI (r=0.732, P<0.001) and with the P-MRI (r=0.598, P<0.001) scores. MRI and US data significantly correlated as to effusion (r=0.819, P=0.002), synovial hypertrophy (r=0.633, P=0.036) and cartilage erosion (r=0.734, P=0.010). Despite inherent limitations, joint US examination identified subclinical abnormalities of HJ in young subjects with severe HA.