Intravenous treatment with biphosphates in Complex Regional Pain Syndrome

BACKGROUND AND AIM OF THE WORK: Complex Regional Pain Syndrome (CRPS) is a pathological persistence of spontaneous or evoked disproportionate pain after a tissue injury. Several drugs are employed, but only bisphosphonates seem to have good outcomes. Bone resorption is the responsible of the demineralization and pain. The purpose of our research is to analyze the characteristics of the cases victims of CRPS of upper extremity and study the beneficial effect of the intravenous nerindronic acid sodium salt (Nerixia®), in an attempt to improve the results in this disabling disease. MATERIALS AND METHODS: We retrospectively examined 30 cases of CRPS that had undergone intravenous nerindronic acid sodium salt therapy in our center. The patients were contacted after 12 months from the start of therapy and their clinical situation was assessed with Quick- Disability of the Arm, Shoulder and Hand (DASH). RESULTS: The average age of our group was 59,76 years (span, 42–78), and female subjects were 84% (p-value <0.05). 72% of all cases were complications of wrist fractures. There’s no relation between the onset of symptoms and the kind of first treatment (conservative or surgical) (p-value >0.05). The DASH Score (19 points are the best result, 95 the worst outcome) average was 41,1 points. The values of differed significantly (p-value <0.001) according to the age of the patient: 100% of patients under the age of 40 years had obtained a score below compared to the general average (< 41,1 points). In addition, the DASH Score values were related to the sex of the patient (p-value <0.001). Male subjects have obtained a better score (> 41,1 points). After 12 months of intravenous therapy, 52% of cases reports that they still have joint stiffness. The DASH values differed significantly depending on the onset of intravenous treatment (p-value <0.001): 100% of the subjects who have had the treatment in lesser than 3 months from the onset of symptoms have obtained worse result than the average of all our population. The 68% of all sample reported to have obtained a subjective improvement of symptoms after the therapy with the nerindronic acid (p-value < 0.05). CONCLUSION: Our study showed that the CRPS affects a population between 42 and 78 years, especially women. Treatment with intravenous bisphosphonates seems to lead to an improvement in CRPS symptoms, in particular administration between 3 and 6 months after the onset of the disease. In particular, women over 61 years of age seem to have a lower improvement in symptomatology after treatment. 52% of cases report that they still have joint stiffness. (www.actabiomedica.it)