Tehran University of Medical Sciences Journal of Orthopedic and Spine Trauma 2538-2330 4 4 2020 05 07 71 73 EN Payam Vezvaei General Practitioner, Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences, Tehran, Iran Soroosh Alizadeh General Practitioner, Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences, Tehran, Iran Saeed Reza mehrpour Associate Professor, Department of Orthopedics, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran Leila Oryadi Zanjani Assistant Professor, Orthopedic Department, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran 2020 01 07 2020 03 13 Background: Complex regional pain syndrome (CRPS) is a painful syndrome with signs such as swelling, restriction of motion, and discoloration of the skin and bone. CRPS is divided into two types based on neurological injuries. Type 1 CRPS (CRPS-I), which is more common, has no nerve damage. In this study, we used the Budapest Criteria to investigate the incidence of CRPS. We also evaluated the risk factors for the incidence of CRPS. Methods: This single-center case series study was performed at Shariati Hospital of Tehran University of Medical Sciences, Tehran, Iran, during 2018-2019. We evaluated CRPS-I, two, and six weeks after treatment based on Budapest Criteria. The inclusion criteria included distal radius fracture confirmed by clinical and radiographic investigations. The exclusion criteria were patients with fractures in another part of the body, associated nerve damage, vascular injury, and an open fracture. Results: Sixty-two patients with distal radius fracture who underwent casting or surgical treatment enrolled in the study. A total of 9 (14.5%) patients had CRPS-I after distal radius fracture. In 5 (8.1%) patients, CRPS-I occurred within two weeks after fracture. Also, 4 (6.5%) patients had CRPS-I after six weeks from fracture. There was no significant difference between the two sex groups in terms of CRPS (P = 0.345). This complication was significantly higher in the surgical group than in the casting group (P = 0.004). Conclusions: Given the significant incidence of CRPS and its impact on patient's quality of life, further studies are recommended to explore solutions to reduce this complication.   https://jost.tums.ac.ir/index.php/jost/article/view/155 https://jost.tums.ac.ir/index.php/jost/article/download/155/131