Antioxidant also not effective in resolving complex regional pain syndrome

Distal radius fractures are common and occur in a relatively young age group (younger than age 60). As a result, complications can have a long-term, deleterious effect on a patient’s ability to function.

“Current treatment methods are aimed at providing stability but no methods have been proven to help soft tissue healing,” said Ingri Ekrol, MD, at the 2009 annual meeting of the Orthopaedic Trauma Association. “Vitamin C has been shown in animal studies to reduce the skeletal muscle injury caused by compartment syndrome, to increase the rate of fracture healing, and to reduce the prevalence of complex regional pain syndrome (CRPS).

“Given the importance of soft tissue healing on the functional outcome of the distal radius, we decided to look at the impact of vitamin C on soft tissues, the prevalence of CRPS, and the rate of fracture healing.”

Vitamin C, placebo randomization
Dr. Ekrol and her colleagues conducted a prospective, randomized, double-blinded, controlled clinical trial from June 2006 to July 2007. It included 336 adult patients with unilateral fractures of the distal radius.

Patients with previous fractures of the distal radius or with bilateral fractures and those on vitamin supplements were excluded from the study.

Patients were divided into two groups based on whether the fracture was displaced (186 patients) or not (150 patients). They were then randomized to receive 500 mg of vitamin C or a placebo for 50 days, starting within 48 hours of the injury.

At each follow-up visit, patients received clinical, functional, and radiologic assessments.

“Functional evaluations included measuring of pain, active range of movement, and grip and pinch strength,” Dr. Ekrol explained. “Bone healing was assessed by cortical bridging and trabeculae crossing the fracture site.”

Most of the fractures (113 displaced and 144 not displaced) were managed with conservative treatment. The remaining fractures were surgically repaired with either external fixation (displaced: 40; not displaced: 6) or open reduction internal fixation (displaced: 33; not displaced: 0).

The effect of Vitamin C
Investigators found no statistically significant differences in Disabilities of the Arm, Shoulder, and Hand scores at any of the tested time intervals (Fig. 1).

A few statistically significant differences were found in movement (wrist flexion) and strength (pinch), but none of these were clinically significant. The outcomes were all worse in the vitamin C group.

At 26 weeks, the displaced fracture group treated with vitamin C had more complications and pain on activity.

“In patients with undisplaced fractures who were treated with vitamin C, we found a statistically significant higher rate of complex regional pain syndrome only at 6 weeks (p = 0.022),” said Dr. Ekrol (Fig. 2).

“This study showed that vitamin C does not improve the patient-rated outcomes, range of movement, strength, rate of complex regional pain syndrome, or bone healing after distal radius fractures,” said Dr. Ekrol. “It also questions the previous evidence of an advantageous effect from administering vitamin C after wrist fractures.”

The authors do not report any conflicts.

Annie Hayashi is the senior science writer for AAOS Now. She can be reached at hayashi@aaos.org

CPG recommendation on vitamin C
The AAOS clinical practice guideline (CPG) on the treatment of distal radius fractures includes a moderate strength recommendation for adjuvant treatment of distal radius fractures with vitamin C for the prevention of disproportionate pain. The rationale for the guideline recommendation is based on two previously published level I studies that examined the role of vitamin C in prevention of complex regional pain syndrome (CRPS) after radius fractures and found a significant reduction in the incidence of CRPS at 1-year follow up.

Dr. Ekrol’s study evaluates the effects of vitamin C on the development of CRPS and on patient function using objective measurements and a patient-oriented outcome tool and does not show any benefit with use of vitamin C over a control group.

No objective “gold standard” test exists to diagnose CRPS and different criteria has been used to diagnose this condition. Based on the available evidence so far, the use of vitamin C remains a recommendation for prevention of disproportionate pain after distal radius fractures. Clearly, additional studies are needed to fully understand the role of vitamin C and development of CRPS.

This information was prepared by Randipsingh R. Bindra, MD, who served as vice-chair of the CPG on distal radial fractures work group.