Objective To present a self-designed self-guided driver for clinical removal of cannulated screws. Methods The diameter of the selfguided rod is 2.8 mm and its length is 50 mm.The hexagonal driver head is 4 mm in height,2 mm in width and 5 mm in length.The other parts are similar to those of a solid driver.We then tested the stabilization of the selfdesigned driver by measuring the lateral load and displacement in 5 different experimental groups.Next we put it into use in the 26 patients who had been treated in our department from July 2008 to July 2009.They had been divided into 2 groups randomly.In the self-guided group,there were 9 males and 4 females,with an average age of 36 years and an interval of 30 months after the first operation.In the solid driver group.there were 7 males and 6 females.with an average age of 43 years and an interval of 21 months after the first operation. Results The mechanical tests revealed that the instrument designed by us was stable and could prevent lateral displacement.In clinic.the 39 screws were removed saccessfully in the self-guide driver group.The mean surgical time and incision in the self-guided driver group were significantly less and smaller than in the solid driver group.Conclnsions The self-guided driver is as stiff as a common solid driver and as stable as a cannulated driver.It can reduce the likelihood of screw invalidation which may make the operation very difficult and timeconsuming.It is a simple,timesaving,and less traumatic instrument,especially fit for removal of cannulated screws of the femoral neck.

Objective To evaluate primary open reduction and wire-pin fixation for total dislocation of talus.Methods A retrospective study was conducted of the 12 patients who had been admitted into our hospital from October 2009 to December 2013 for total talar dislocation without fracture of the talar neck or body and had been available for complete follow-up.They were 10 males and 2 females.Their range of age was from 17 to 56 years (average,34.2 years).The total dislocation was open in 4 cases and close in 8.All of them underwent primary open reduction and wire-pin fixation.The functions of ankle joint and hindfoot were evaluated according to the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale.Results The follow-up time ranged from 22 to 72 months (average,35.6 months).Postoperatively,one case suffered skin necrosis and another superficial infection,both of whom responded to skin flap transferring after debridement.Traumatic arthritis of the talotibial or subtalar joint was found more or less in 7 cases,one of whom complained of severe pain but refused the subtalar arthrodesis advised.Their AOFAS scores at the final follow-up ranged from 42 to 96 points (average,72.2 points).Five cases developed avascular necrosis of the talus,but no talar collapse happened.Conclusions Primary open reduction and wire-pin fixation is effective for treatment of close total talar dislocation and open total dislocation of Gustilo type Ⅲ A or below.Although avascular necrosis and traumatic arthritis are common postoperative complications,satisfactory functions can be achieved if there is no collapse,severe pain or infection.