Patients living with rheumatoid arthritis may experience symptoms which cannot be detected by just looking at their body.  Even squeezing and poking the tissues surrounding tender joints may not make swelling entirely obvious.  Doctors often have to trust that when we say, “ouch,” we really do mean it.

There have been times where one of my RA symptoms was the “walking on rocks” sensation in my feet.  Really quite unpleasant.  Some people might describe this sensation as walking on marbles or walking on pebbles.  Researchers at the University of Southampton aim to improve the health and mobility of RA patients who experience the “walking on marbles” pain. 

Last fall one of our health guides, V, asked, “Anyone else feel as though they are walking on rocks?”  Responses to her question reveal that this is truly a common complaint.

Investigators have developed new ways of using diagnostic ultrasound and MRI (magnetic resonance imaging) techniques to assess a patient’s feet, specially the area around the ball of the foot and toes.  Previously, it was thought that this pain was due to walking on joints which were directly affected by RA.  

However, research conducted by Southampton scientists as part of the Health Sciences’ FeeTURA study between 2006 and 2009, using ultrasound and MRI, reveals that the walking on rocks sensation is caused by inflamed bursae, fluid-filled sacs found in areas subject to friction.  When the bursae beneath the toes become inflamed, it is difficult to detect during clinical examination.

Researchers used MRI to visualize the anatomical structures and inflamed bursae (or “marbles”) in the feet more clearly.  As a result, they developed a method to categorize the swellings which had been identified by ultrasound in patients at the beginning of the FeeTURA study.  (See the press release for an MRI image of the “marbles” seen in a patient.)

RA is a disease which results in damage to joints, and other body tissues, caused by inflammation.  RA affects approximately 1.3 million people in the United States (US) and 600,000 people in the United Kingdom (UK) where this research is taking place.

The cause of the inflamed bursae is not yet known and there is no cure.  But researchers are beginning a new stage of their study to look at identifying inflammatory markers and mechanical characteristics of inflamed bursae in order to discover the best ways to treat this problem which can occur in people with RA.  As part of the study, they will evaluate different treatment approaches, such as targeted steroid injections and biologic therapies.

The next phase of research will be led by Dr. Catherine Bowen, senior lecturer for advanced clinical and expert practice, and conducted by Lindsey Hooper, a clinical academic researcher and rheumatology podiatrist.  The study will be funded through a partnership between Solent NHS Trust and the Faculty of Health Sciences at the University of Southampton and supported by a National Institute for Health Research (NIHR) clinical academic fellowship.