Complex regional pain syndrome, or CRPS, can develop after an injury, but the cause isn’t yet understood. Researchers do know that inflammation plays a role and previous studies have suggested that the body’s reaction in CRPS can be similar to that of a burn. Researchers looking into burn treatment have found that giving high doses of vitamin C to burn patients helped reduced the amount of fluid they needed and reduced the swelling. With this in mind, the authors of this study wanted to see if giving vitamin C to patients with a new broken wrist would decrease their chances of developing CRPS.
The study took place at 3 hospitals in the Netherlands and involved 416 women who had a total of 427 wrist fractures. The patients were randomly chosen to receive vitamin C (317 women, 328 fractures) or placebo, a sugar pill, (99 women, 99 fractures). Among the women taking vitamin C, 96 took 200 mg, 114 took 500 mg and 118 took 1500 mg, per day. The patients did not know if they were taking the vitamin or the placebo. They were evaluated 1 week after the injury, when the cast was removed (at 4 or 5 weeks), again at 6 or 7 week, 12 weeks, and 26 weeks. They were evaluated one more time at 1 year by phone or by mail.
The researchers made a diagnosis of CRPS if the patient showed 4 of the following 5 symptoms at the affected wrist: unexplained pain out of proportion to the injury, skin color difference between the affected hand and the other hand, skin temperature difference between the affected hand and the other hand, swelling, and limited range of motion unrelated to the fracture.
The researchers found that 2.4 percent of the women in the vitamin C group developed CRPS while 10.1 percent in the placebo group did. When the researchers looked at the amount of vitamin C taken by the women, there wasn’t much of a difference between the women who took the lowest dose vitamin C (200 mg) and the women who took the placebo. But, there was a significant difference between the women who took the higher doses of the vitamin.
The average time for development of CRPS was 76 days (ranging from 30 to 166 days). One patient who had fractured both wrists developed CRPS in one, but not the other. She was taking 1500 mg of vitamin C. The researchers also found that when patients complained of discomfort from their casts, this could predict the development of CRPS. This was similar to findings from previous studies, according to the authors.
The authors point out some limitations in the study, including the number of patients and verification of patient compliance. Nonetheless, they conclude that administration of 500 mg of vitamin C following a wrist fracture, for 50 days, may prevent CRPS.