The value of ultrasound compared to magnetic resonance imaging in haemophilic arthropathy

Repeated provoked or spontaneous bleeding into the joints are the hallmark of
haemophilia. Recurrent or prolonged joint bleeds eventually lead to synovial
hypertrophy, progressive cartilage degradation and bone damage through
mechanical and metabolic joint destruction. Joint assessment in haemophilia is
important to assess results of the expensive replacement therapy with clotting
factor concentrates. Traditionally, the six main joints (elbows, knees, and
ankles) were examined with standard X-rays. However, standard X-rays are able
to assess osteochondral changes only, and therefore detect late and mostly
irreversible joint changes. From a clinical perspective, it is important to
assess early, potentially reversible, joint changes in patients with normal
findings on physical examination and X-ray. Consequently there is an increasing
interest in the use of Magnetic Resonance Imaging (MRI) and ultrasound. MRI is
the most sensitive imaging modality to demonstrate effusion or haemartrosis,
synovitis, and cartilage defects. However, MRI assessment is less available
than a standard X-ray, it is expensive and time consuming. Therefore MRI is not
the first choice for routine joint assessment in the absence of major
complaints. The typical haemophilic joint changes including effusion or
haemartrosis, synovitis, and cartilage defects can be assessed by ultrasound
too and show strong correlations with MRI findings. Unfortunately the operator
dependency of ultrasound is a potential disadvantage, and previous ultrasound
protocols for haemophilic arthopathy were too time consuming to use in daily
practice. For both imaging modalities new scoring systems have been published
recently to evaluate haemophilic arthropathy: the MRI scale by the
International Prophylaxis Study Group (IPSG) and a simplified ultrasound
scanning procedure (Haemophilia Early Arthropathy Detection with Ultrasound
(HEAD-US)). So far, there is no literature available about the accuracy of the
HEAD-US score compared to MRI. The clinical relevance of early changes detected
by MRI and ultrasound is still unclear. It is not known if subtle alterations
such as haemosiderin and synovial hypertrophy seen on MRI are reversible or
not, and if they have a predictive value for development of osteochondral
changes.

The primary objective of this study is to establish the diagnostic accuracy of
ultrasound assessment of the synovium in haemophilic arthropathy compared to
MRI. Secondary objectives are (2A) to determine whether or not synovial
hypertrophy on MRI is able to predict osteochondral changes on MRI five years
later and (2B) to evaluate if intra-articular haemosiderin be cleared in five
years.

Cross-sectional study for the primary objective on the value of ultrasound in
patients with haemophilia. Longitudinal observational study for the secondary
objectives using clinical follow-up and baseline data of a previous MRI study
(METC 07-220).

Participating patients will spent more time in the hospital at the day of their
planned clinical follow-up due to the additional US and MRI examination.
Patients will not have a direct benefit from participating in this study: their
bleeding pattern and current outcome will not change. On long term, patients
are expected to benefit from the optimization of treatment due to detailed
assessment of outcome.