Objective To compare the clinical effects of closed reduction and intramedullary nailing versus open reduction and plate fixation in the treatment of displaced midshaft clavicular fractures.Methods A prospective,randomized,controlled trial was performed between July 2012 and May 2014 in 194 patients with acute displaced midshaft clavicular fracture.They were 136 males and 58 females,from 16 to 65 years of age.They were randomly divided into 2 groups to received either closed reduction and intramedullary nailing (n =98) or open reduction and plate fixation (n =96).We recorded operation time,intraoperative blood loss,hospitalization expenses,fracture healing time and complication rate.Functional assessments were conducted at 3,6 and 12 months using the Disabilities of the Arm,Shoulder and Hand (DASH) and Constant-Murley scores.The preoperative general data showed no statistical significance between the 2 groups (P ＞ O.05).Results All the 194 patients were followed up for 12 to 27 months (average,15.6 ±3.1 months).The operation time (27.7 ± 16.3 min),intraoperative blood loss (18.6 ± 14.4 mL),hospitalization expenses (12,462.0 ±3,263.4 yuan),and fracture healing time (12.1 ± 3.0 weeks) in the intramedullary nailing group were significantly better than those(62.3 ± 19.4 min,40.3 ± 17.4 mL,24,760.0 ± 3,320.4 yuan,and 16.9 ± 2.8 weeks) in the plate fixation group (P ＜ 0.05).At 3 months after surgery,the DASH (13.4 ± 3.5) and Constant-Murley (88.5 ±5.9) scores in the plate fixation group were significantly better than those (24.8 ± 6.7 and 69.1 ± 6.2,respectively) in the intramedullary nailing group (P ＜ 0.05).At 6 and 12 months after surgery,there were no significant differences in the Constant-Murley scores or DASH scores between the 2 groups (P ＞ 0.05).The complication rate in the intramedullary nailing group (25.5％,25/98) was significantly higher than in the plate fixation group (9.4％,9/96) (P ＜ 0.05).Conclusions In the treatment of displaced midshaft clavicular fractures,compared with open reduction and plate fixation,closed reduction and intramedullary nailing has advantages of less invasion,lower cost and faster fracture healing,but a disadvantage of higher complication rate.The 2 treatments may lead to similar functional recovery of the shoulder.