Haemophilic Arthropathy Assessment with the Use of Ultrasound

MICHAEL HOCKEY
Michael Hockey is Advanced Physiotherapist, Haemophilia, Queensland Haemophilia Centre, Royal Brisbane and Women’s Hospital

Haemophilic arthropathy refers to permanent joint disease occurring in people with haemophilia as a result of repeated bleeding into the joint. Medical Imaging (eg. X-ray) of affected joints has long been recommended as playing an important role in assessment. Ultrasound scanning is one type of imaging that has been proposed as a useful diagnostic tool in the assessment of haemophilic arthropathy.

Repeated joint bleeds causes damage to the joint surface. Healthy synovial tissue, the membrane lubricated by synovial fluid in freely moving joints, is very effective at clearing blood from the joint after an initial bleed. However, after the insult of multiple bleeds the synovium becomes chronically inflamed. It also becomes less able to clear blood and its waste products from the joint. Iron, which is a component of blood, builds up in the joint leading to the death and disruption of cartilage cells. This leads to a progressive destruction of the joint surface. Secondary changes include the formation of cysts and osteoporosis.

Often in the early stages of arthropathy no ongoing symptoms are apparent. As the disease progresses, symptoms of pain, swelling, stiffness and decreased joint motion may be experienced. Ultimately the disease can progress to the point where the joint surface is so degraded that the joint no longer moves.

Photo: X-ray images of an elbow demonstrating bony cysts and destruction of the joint surface due to haemophilic arthropathy

DIAGNOSTIC TOOLS

Medical imaging plays an important role in the examination of arthropathic joints. Current diagnostic tools include plain film X-ray and MRI. The benefits of X-ray include low cost and ease of access. X-ray is a useful tool to monitor the appearance of bony surfaces and joint space over a period of time. It is not able to view the soft tissues of the joint effectively. MRI has long been considered the gold standard for joint imaging. It reveals much information about the bony and soft tissue structures. The main limitations of MRI are high cost, often long wait times, length of time taken for each imaging procedure and the need for the patient to remain still during this period. This last point is especially pertinent when considering the paediatric patient, who may not be willing to stay still for so long.

Ultrasound scanning has been an area of high interest in recent years in imaging of the haemophilic arthropathic joint. Most people know ultrasound scanning as the type of procedure used to look at a foetus in utero. Other uses for ultrasound include imaging of muscles, joints and tendons. Many physiotherapists will have some level of experience in using ultrasound to image the deep muscles of the abdomen and back. Ultrasound scanning has been proposed as an inexpensive adjunct imaging diagnostic tool that can be incorporated into everyday clinical practice.

HEAD-US

At WFH Congress earlier this year many of the physiotherapists from our national group attended an evening session on ultrasound. Carlo Martinoli, Associate Professor of Radiolgy at the University of Genoa, Italy, presented the session. Together with his team he has constructed a protocol known as HEAD-US (Haemophilia Early Arthropathy Detection with Ultrasound) for the easy assessment of haemophilic joints. Images are taken of the elbows, knees and ankles. For each joint the synovium, cartilage and bone is imaged and assessed. Ultrasound head placement is very prescriptive. For the elbow there are five positions, knee four and ankle five. An additive score is then calculated giving a numerical indication of joint disease activity, and disease damage.

In the current Australian system ultrasound scanning is generally performed by a sonographer. (A sonographer has completed a university degree on ultrasound scanning). However, it actually loses some of its value in the case of the haemophilic joint, when the patient needs to be referred to the sonographer, await the scan and then the results. Professor Martinoli suggests that physiotherapists are in a perfect position to take up this protocol for use as part of day to day practice.

Being so specific and prescriptive, the HEAD-US protocol is relatively easy to learn and apply. Professor Martinoli claims that once a clinician is proficient with its application, an assessment of all six joints can be completed within a few minutes. However, for a novice user the full assessment takes a significant length of time.

An advantage of incorporating ultrasound imaging into clinical practice would be the ability to see immediately whether the ultrasound images line up with the physical assessment findings. Evidence suggests that both clinicians and patients alike find it difficult to differentiate between arthropathic pain, and the pain caused by a minor bleed. The HEAD-US protocol is sensitive enough to pick up early changes in cartilage and subchondral surfaces below the cartilage. By imaging the bone, cartilage and synovium the clinician is in a much stronger position to able to say whether the symptoms that are being experienced are in keeping with an underlying joint pathology.

Professor Martinoli proposed that this would be a perfect protocol to integrate into annual joint health assessments. I am not aware of any of our national group physios who have taken him up on his recommendation. We as yet do not have the training or equipment in order to allow us to do this. We are as a group, however, very keen on further education in this area and on considering how it may play a role in our clinical practice.

So watch this space. In the future physios may have ultrasound scanning as another joint health assessment option.