Objective To evaluate the accuracy of thoracic pedicle screw placement using the "funnel technique" and investigate its consistency in experimental study and clinical application.Methods The clinical data of three human cadavers and 11 patients with the installation of at least one thoracic pedicle screw at T1 -T12 from August 2006 to July 2008 were retrospectively analyzed. One junior spine surgeon lack of experience were responsible for placing these screws with the "funnel technique".The accuracy of screw placement and the complications related to the use of thoracic pedicle screws were analyzed by assessing postoperative CT scans. Results The mean follow-up time was 23.1 months,which showed no vascular or visceral complications, or iatrogenic neurological injury. The rate of unintended cortex perforations was 14% (10/72) in cadavers and 15% (8/55) in patients, respectively.The critical perforation occurred in two screws (3%) in cadavers and one screw (2%) in patients. There was no statistical difference between the percentage of cortex perforations in cadavers and patients. Of all the 11 patients, screw violation occurred laterally in six ( 11% ), medially in one ( 2% ) and superiorly in one (2%). No violations occurred inferiorly or anteriorly. For all patients, only one screw needed revision. The perforations made by the junior spine surgeon occurred in six screws in the first cadaver, three in the second cadaver and one in the third cadaver. Conclusions The "funnel technique" is a simple,safe, accurate and cost-effective technique for pedicle screw placement. The result of the experimental study is consistent with that of the clinical application. "funnel technique" is helpful for junior spine surgeons to master the technique of thoracic pedicle screw placement.

Objective To study the risk factors for perioperative heart failure in the elderly patients with femoral intertrochanteric fracture so as to provide guide information for prevention of the perioperative heart failure.Methods Included in this retrospective study were 175 elderly patients with femoral intertrochanteric fracture who had undergone closed reduction and intramedullary nail fixation in our hospital from May 2013 to August 2016.They were divided into 2 groups.In the heart failure group of 31 cases,there were 12 males and 19 females,with an age of 73.5 ± 7.8 years;in the non heart failure group of 144 cases,there were 61 males and 83 females,with an age of 69.8 ± 6.9 years.The 2 groups were compared in terms of age,early surgery,hypertension history,respiratory disease history,heart disease history,disturbance of consciousness,preoperative renal function,operation time,anesthesia method,operation time,perioperative fluid volume difference,perioperative pain score,and postoperative hemoglobin.After univariate analysis of these factors,the risk factors were determined through the multivariate regression analysis.Results The univariate analysis showed that age,heart disease history,perioperative fluid volume difference and perioperative pain score were statistically different between the 2 groups (P ＜ 0.05).By the multivariate analysis,the risk factors for perioperative heart failure were age [P =0.014,OR =1.063 (1.012,1.116)],heart disease history [P =0.008,OR =4.977 (1.526,16.230)],perioperative fluid volume difference [P =0.025,OR=2.421 (1.117,5.249)],and perioperativepain score [P=0.040,OR=2.292(1.040,5.050)].Conclusions Age,heart disease history,perioperative fluid volume difference and perioperative pain score may be the risk factors for perioperative heart failure in elderly patients with femoral intertrochanteric fracture.We should pay attention to these factors and evaluate their influences on the patient so as to take appropriate perioperative prevention and treatment measures to reduce the incidence of perioperative heart failure.