An MRI scan is the best way to detect joint problems early on in people with haemophilia. This is the main conclusion from a study by a team from Utrecht university hospital in the Netherlands, that was recently published in Blood Advances.
Recurrent bleeding episodes into joints and muscles form a common occurrence in patients with haemophilia. Bleeding most commonly occurs in the knees, elbows and ankles, often from early childhood on. If joint bleeding is not treated adequately, it tends to recur, resulting in a vicious cycle that must be broken to prevent the development of chronic synovitis and degenerative arthritis.
Normally, X-rays are used to examine the joints, but this imaging technique is unable to detect early abnormalities in cartilage and connective tissue. Early diagnosis of abnormalities enables specialists to start treating patients at an early stage, which can prevent irreversible damage later on in life.
The synovium, the connective tissue that lines the inside of the joint capsule, plays a crucial part in the pathogenesis of haemophilia artropathy. Hypertrophy of the synovium with neovascularization raises the risk of bleeding. In-vitro studies have shown that abnormalities of the synovium can cause metabolic defects in the bone and in joint cartilage.
The fact that MRI is not used more frequently in the examination of joints in haemophilia patients may be related to limited availability as well as higher costs, researcher dr. Wouter Foppen thinks. Furthermore, the clinical relevance of early abnormalities in the synovium and cartilage had not been established yet. The team from Utrecht conducted a prospective cohort study over 5 years in order to establish the link between early signs of abnormality, such as were detected with MRI scanning, and joint bleeding.
For a period of 5 years, 26 haemophilia patients between 12 and 30 years old were followed, with moderately severe to severe haemophilia. In all of them, X-rays showed little or no evidence of abnormalities in synovium or cartilage. At the onset of the study, all patients underwent an MRI scan and echography of knees and ankles. In total, this gave data on 104 joints in total, of which 36% experienced bleeding during the 5 years follow-up.
The absolute bleeding risk was 80% for joints with hypertrophy of the synovium and 27% in joints that did not have this affliction. (p<0.01). Hypertrophy of the synovium in an MRI scan proved to be an important indicator for joint bleeding later on. If an MRI of a test subject at the beginning of the study showed abnormalities in the bone, synovium or cartilage that did not show up on regular X-rays, there was a higher risk of radiographic abnormalities 5 years later (positive predictive value 75%, negative predictive value 98%)
Dr. Foppen concluded that an MRI scan of the joints provides relevant early information about haemophilia patients who suffer no or little joint bleeding. By monitoring the condition of the joints, treatment can be adjusted when deemed necessary.
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