Background The treatment of CRPS remains controversial, but multidisciplinary and interdisciplinary approaches seem to be inevitable to prevent long-standing or permanent disability (1). Bisphosphonates, apart from their antiresorptive activity, could also have other properties through a specific analgesic or anti-inflammatory effect.Bisphosphonate therapy has been shown to be effective in single cases of CRPS (2).

Objectives to evaluate the efficacyof intravenous compared with intramuscular bisphosphonates in reducing pain in patients with CRPS.

Methods 14 patients (one male and 13 females; mean age 64.3±8 years) diagnosed with CRPS of carpal and metacarpals bones (confirmed by clinical and MRI) from two weeks, were treated with non-steroidal anti-inflammatory drugs (NSAID), supplemental calcium and Vitamin D, physical therapy and clodronate. Seven patients were treated with iv (Group A) and seven with im clodronate (Group B) for 2 weeks. Then all patients were subjected to im clodronate 100 mg/weekly for 3 months. Pain scales (VAS 0-100) and joint examination were performed before, after one week and after 3 months of clodronate therapy.

Results pain was 92.7±12 mm in group A and 91±7.5 mm in group B, before starting clodronate (t0). Clodronate reduces pain significantly (p=0.0001) in both groups after one week of therapy, but reduction of pain was significantly higher (p=0.0001) in patients treated with iv clodronate (VAS 21.8±7 mm in group A vs 48.2±9.1 mm in group B). After 3months, nostatistical significant difference (p=0.7) in painwas found. Rapid reduction of pain in group A is associated also to a rapid reductionof hyperhidrosis, edema and joint stiffness after one week of therapy.No adverse effects were reported during therapy.

Conclusions Iv clodronate achieves a rapid reduction of pain compared to im formulation, in patients with CRPS. Early intervention and reduction of pain is also associated with a rapid clinical improvement that might help in the prevention of long-standing disability.

1. Tran de QH, Duong S, Bertini P, Finlayson RJ. Treatment of complex regional pain syndrome: a review of the evidence.

2. Simm PJ, Briody J, McQuade M, Munns CF. The successful use of pamidronate in an 11-year-old girl with complex regional pain syndrome: response to treatment demonstrated by serial peripheral quantitative computerised tomographic scans. Bone 2010 Apr;46(4):885-8. Epub 2009 Dec 5.

Disclosure of Interest None Declared