Fracture pain study paper from Integrated Pain Management HIT published

Members of the Integrated Pain Management Health Integration Team (IPM HIT) have published a paper looking at ‘sensorimotor dysfunction’ after limb fracture. Sensorimotor dysfunction is when people feel sensations or movements in a limb that aren’t actually happening.

The paper, called ‘Sensorimotor dysfunction after limb fracture – An exploratory study’, was published in the European Journal of Pain in October. The research team found that in the immediate post-fracture period, patients report:

• Disturbance of limb perception in the fractured limb
• Imagined movements of the fractured limb are less vivid compared to non-fractured and associated with pain

Broken bones or fractures are common, and wrist and ankle fractures especially so. Whilst the vast majority of limb fractures heal without complication many are associated with long-term pain and disability which often extends beyond the local effect of the original injury. Limb fracture is also a known trigger for complex regional pain syndrome (CRPS), which is a chronic pain condition, characterised by extreme pain and sensory changes with the limb demonstrating colour, temperature, swelling and sweating changes (known as autonomic changes). The cause of CRPS is unknown and it is thought that early treatment may help to minimise long term disability. Therefore predicting who might develop CRPS after limb fracture is essential to starting the appropriate treatment as soon as possible.

The aim of this exploratory study was to investigate sensation and task performance shortly after wrist and ankle fractures to understand the effects of early dysfunction on later development of chronic pain. The second aim was to determine the incidence of complex regional pain syndrome (CRPS) and its clinical features.

How the study was carried out?

Fifty-three patients at a UK fracture centre, who either had a wrist or ankle fracture, were recruited.

Testing for differences between the fractured and non-fractured limb was carried out within five weeks of fracture when many patients were still in plaster casts. Tests were performed on limb sensation, such as the ability to discriminate between hot and cold and pressure, limb perception and ability to imagine movement. About five weeks later patients were examined for signs and symptoms of CRPS and asked about their perception of recovery. At both testing sessions, and again six months later, patients completed various questionnaires that asked about pain, function and ps ychological distress.

Results

Fifty-three patients with a mean age of 54 years completed the study. Thirty-six of these were female. Thirty-six patients had wrist fractures and 17 had ankle fractures. Most patients were treated with plaster casts (57 per cent), and the remainder with surgery.

Results from the various tests are below:

• Sensory tests – the fractured limb was more sensitive to cold and pressure than the non-fractured
• Limb perception – some patients had significant difficulty in perceiving the fractured limb normally
• Imagined movements – patients found that imagining a limb movement (e.g. imagining moving wrist or ankle up and down) was significantly more difficult on the fractured side
• Thirty-three per cent of patients reported to being “back to normal” six months after fracture and 34 per cent reported ongoing pain
• 9.4 per cent of the sample developed CRPS

What does it all mean?

There was considerable delay in self-assessed recovery after limb trauma and fracture healing. Ongoing persistent pain was not unusual post wrist or ankle fracture, with analgesia providing diminishing relief. Disturbance of the patients’ ability to imagine movement on the fractured side suggests disruption of brain processing of movement. Limb perception of the fractured limb was also disturbed, suggesting the way in which the brain maps the body is affected by limb trauma. As this was an exploratory study, definitive conclusions on determining whether early detection of problems and appropriate intervention can improve outcomes require further study.

Paper

Sensorimotor dysfunction after limb fracture – An exploratory study
Jane. Hall¹, Alison Llewellyn ¹, Shea. Palmer², Jane. Rowett-Harris³, Roger.M. Atkins ³ and Candy. S. McCabe.^1,2