Objective To analyze the clinical effect of percutaneous sacroiliac screw internal fixation in treatment of sacroiliac joint dislocation. Methods From June 2002 to August 2006,16 patients with sacroiliac joint dislocation were treated with percutaneous sacroiliac screw internal fixation under C-arm X-ray tomography.There were 10 males and 6 females at age range of 10-58 years(mean 34.3 years).Results The operation lasted for 30-90 minutes(average 50.5 minutes).All patients were followed up for 12-36 months(average 18.3 months).The results of postoperative normotopia,lateral,ingate and egress Xray and CT scanning showed that all the screws were located within S1 and S2 of all,14 patients obtained satisfactory result of reduction,with no infection,nerve injuries,loosening or breakage of the screw fixation.The function and the sensation of the sacroiliac ioint and low extremities recovered to normal. Conclusions Percutaneous sacroiliac screw intemal fixation is an ideally safe and effective way to treat sacroiliac joint dislocation,for it has many advantages such as minimal invasion,reliable fixation,less complication and quick recovery.It is also very necessary to take caudad and cephalad view under an image intensifier during the operation to assure the accuracy of implantation.