Complex regional pain syndrome (CRPS) is a disabling condition that causes motor impairment. It is common after wrist fracture. Little is known about the epidemiology of CRPS and there has been very little research into prevention and treatment of CRPS.
We sought to (a) determine the incidence of CRPS, and (b) identify people at high risk of developing CRPS.
Several studies provide data on incidence of CRPS after wrist fracture but those studies were conducted on small or unrepresentative samples or used diagnostic criteria that are not widely accepted. The current study was conducted on a nearly consecutive sample of 1,549 patients with wrist fracture presenting to hospital fracture clinics. Participants were assessed for potential prognostic factors within a week of fracture, and they were re-assessed for the presence of CRPS using established diagnostic criteria 4 months later.
WHAT DID WE FIND?
The incidence of CRPS in people presenting to fracture clinics after wrist fracture was 3.8% (95% CI 2.9 to 4.8%).
A simple prediction model based on pain, reaction time, dysynchiria (a sensory response on the fractured side to stimulation of the opposite side) and swelling in the first week after fracture was able to accurately predict people who went on to develop CRPS. Prognostications that were almost as accurate could be made simply by asking participants about their pain within the first week after fracture. Pain was rated on a 0-10 scale. No patient who rated their pain as 3/10 or less went on to develop CRPS, but nearly half of those who rated their pain as 5/10 or more developed CRPS.
SIGNIFICANCE AND IMPLICATIONS:
CRPS is a not uncommon complication of wrist fracture. Given the incidence of CRPS and that it can be very disabling, more research into its prevention and treatment is warranted.
In the first week after wrist fracture it is easy to quite accurately identify people who will go on to develop CRPS. Preventive interventions could be targeted at these people.
Moseley GL, Herbert RD, Parsons T, Lucas S, van Hilten JJ, Marinus J (2014). Intense pain soon after wrist fracture strongly predicts who will develop complex regional pain syndrome: prospective cohort study. J Pain 15: 16-23.
Marinus J, Moseley GL, Birklein F, Baron R, Maihofner C, Kingery WS, van Hilten JJ (2011). Clinical features and pathophysiology of complex regional pain syndrome. Lancet Neurol 10:637-648, 2011.
Bruehl S, Harden RN, Galer BS, Saltz S, Bertram M, Backonja M, Gayles R, Rudin N, Bhugra MK, Stanton-Hicks M (1999). External validation of IASP diagnostic criteria for complex regional pain syndrome and proposed research diagnostic criteria. Pain 81:147-154.