Printed Three-dimensional Anatomic Templates for Virtual Preoperative Planning Before Reconstruction of Old Pelvic Injuries： Initial Results

Background：Old pelvis fractures are among the most challenging fractures to treat because of their complex anatomy,difficult-to-access surgical sites,and the relatively low incidence of such cases.Proper evaluation and surgical planning are necessary to achieve the pelvic ring symmetry and stable fixation of the fracture.The goal of this study was to assess the use of three-dimensional （3D） printing techniques for surgical management of old pelvic fractures.Methods：First,16 dried human cadaveric pelvises were used to confirm the anatomical accuracy of the 3D models printed based on radiographic data.Next,nine clinical cases between January 2009 and April 2013 were used to evaluate the surgical reconstruction based on the 3D printed models.The pelvic injuries were all type C,and the average time from injury to reconstruction was 11 weeks （range：8-17 weeks）.The workflow consisted of.：（1） Printing patient-specific bone models based on preoperative computed tomography （CT） scans,（2） virtual fracture reduction using the printed 3D anatomic template,（3） virtual fracture fixation using Kirschner wires,and （4） preoperatively measuring the osteotomy and implant position relative to landmarks using the virtually defined deformation.These models aided communication between surgical team members during the procedure.This technique was validated by comparing the preoperative planning to the intraoperative procedure.Results：The accuracy of the 3D printed models was within specification.Production of a model from standard CT DICOM data took 7 hours （range：6-9 hours）.Preoperative planning using the 3D printed models was feasible in all cases.Good correlation was found between the preoperative planning and postoperative follow-up X-ray in all nine cases.The patients were followed for 3-29 months （median：5 months）.The fracture healing time was 9-17 weeks （mean：l0 weeks）.No delayed incision healing,wound infection,or nonunions occurred.The results were excellent in two cases,good in five,and poor in two based on the Majeed score.Conclusions：The 3D printing planning technique for pelvic surgery was successfully integrated into a clinical workflow to improve patient-specific preoperative planning by providing a visual and haptic model of the injury and allowing patient-specific adaptation of each osteosynthesis implant to the virtually reduced pelvis.

Percutaneous Sacroiliac Screw Placement： A Prospective Randomized Comparison of Robot？assisted Navigation Procedures with a Conventional Technique

Background： Sacroiliac （SI） screw fixation is a demanding technique, with a high rate of screw malposition due to the complex pelvic anatomy. TiRobot- is an orthopedic surgery robot which can be used for SI screw fixation. This study aimed to evaluate the accuracy of robot-assisted placement of SI screws compared with a freehand technique. Methods：Thirty patients requiring posterior pelvic ring stabilization were randomized to receive freehand or robot-assisted SI screw fixation, between January 2016 and June 2016 at Beijing Jishuitan Hospital. Forty-five screws were placed at levels S1 and S2. In both methods, the primary end point screw position was assessed and classified using postoperative computed tomography. Fisher＇s exact probability test was used to analyze the screws＇positions. Secondary end points, such as duration of trajectory planning, surgical time after reduction of the pelvis, insertion time for guide wire, number of guide wire attempts, and radiation exposure without pelvic reduction, were also assessed. Results： Twenty-three screws were placed in the robot-assisted group and 22 screws in the freehand group; no postoperative complications or revisions were reported. The excellent and good rate of screw placement was 100% in the robot-assisted group and 95% in the freehand group. The P value （0.009） showed the same superiority in screw distribution. The fluoroscopy time after pelvic reduction in the robot-assisted group was significantly shorter than that in the freehand group （median [Q1, Q3]： 6.0 [6.0, 9.0] s vs. median [Q1, Q3]： 36.0 [21.5, 48.0] s; χ2 = 13.590, respectively, P 〈 0.001）; no difference in operation time after reduction of the pelvis was noted （χ2 = 1.990, P = 0.158）. Time for guide wire insertion was significantly shorter for the robot-assisted group than that for the freehand group （median [Q1, Q3]： 2.0 [2.0, 2.7] min vs. median [Q1, Q3]： 19.0 [15.5, 45.0] min; χ2 = 20.952, respectively, P 〈 0.001）. The number of guide wire attempts in the robot-assisted group was significantly less than that in the freehand group （median [Q1, Q3]： 1.0 [1.0,1.0] time vs. median [Q1, Q3]： 7.0 [1.0, 9.0] times; χ2 = 15.771, respectively, P 〈 0.001）. The instrumented SI levels did not differ between both groups （from S1 to S2, χ2 = 4.760, P = 0.093）. Conclusions： Accuracy of the robot-assisted technique was superior to that of the freehand technique. Robot-assisted navigation is safe for unstable posterior pelvic ring stabilization, especially in S1, but also in S2. SI screw insertion with robot-assisted navigation is clinically feasible.

Safety of early surgery for geriatric hip fracture patients taking clopidogrel:a retrospective case-control study of 120 patients in China

Background:Geriatric hip fracture patients receiving clopidogrel are a surgical challenge.In China,most of these patients undergo delayed surgical treatment after clopidogrel withdrawal for at least 5 to 7 days.However,delayed surgery is associated with increased complications and mortality in the older adults.This retrospective paralleled comparison study investigated the safety of early surgery for geriatric hip fracture patients within 5 days of clopidogrel withdrawal.Methods:Acute hip fracture patients(≥65 years)who were hospitalized in the orthogeriatric co-management ward of Beijing Jishuitan Hospital between November 2016 and April 2018 were retrospectively reviewed.Sixty patients taking clopidogrel before injury and discontinued<5 days before surgery constituted the clopidogrel group.The control group constituted 60 patients not taking antiplatelet or anticoagulant drugs and matched 1:1 with the clopidogrel group for sex,fracture type,operative procedure,and time from injury to operation(±10 h).The primary outcome was perioperative blood loss and the secondary outcomes were transfusion requirement,complications,and mortality.The Student’s t test or Wilcoxon signed rank sum test was used for continuous variables and the Chi-square test was used for categorical variables.Results:Age,body mass index,American Society of Anesthesiologists score,and percentage undergoing general anesthesia were comparable between the groups(P>0.050).The percentages of patients with coronary heart disease(61.7%vs.18.3%;P<0.001)and cerebrovascular disease(45.0%vs.15.0%;P<0.010)were significantly higher in the clopidogrel vs.control groups,respectively.The median clopidogrel discontinuation time before operation was 73.0(range:3.0–120.0)h.There was no significant difference in the estimated perioperative blood loss between the clopidogrel group(median:745 mL)and control group(median:772 mL)(P=0.866).The intra-operative transfusion rate was higher in the clopidogrel group(22/60,36.7%)than that in the control group(12/60,20.0%)(P<0.050).However,there was no significant difference in the blood transfusion rate during the entire perioperative period(26/60,43.3%vs.20/60,33.3%;clopidogrel group vs.control group,respectively;P>0.050).There was no significant difference in perioperative complications,and 30-day and 1-year mortality rates between the groups.Conclusions:Early hip fracture surgery is safe for elderly patients within 5 days of clopidogrel withdrawal,without increased perioperative blood loss,transfusion requirement,complications,and mortality compared with patients not taking antiplatelet drugs.

ALD-induced TiO_(2)/Ag nanofilm for rapid surface photodynamic ion sterilization

The daily life of people in the intelligent age is inseparable from electronic device,and a number of bacteria on touch screens are increasingly threatening the health of users.Herein,a photocatalytic TiO_(2)/Ag thin film was synthesized on a glass by atomic layer deposition and subsequent in situ reduction.Ultraviolet-visible(UV-Vis)spectra showed that this film can harvest the simulated solar light more efficiently than that of pristine TiO_(2).The antibacterial tests in vitro showed that the antibacterial efficiency of the TiO_(2)/Ag film against S.aureus and E.coli was 98.2%and 98.6%,under visible light irradiation for 5 min.The underlying mechanism was that the in-situ reduction of Ag on the surface of TiO_(2)reduced the bandgap of TiO_(2)from 3.44 to 2.61 eV due to the formation of Schottky heterojunction at the interface between TiO_(2)and Ag.Thus,TiO_(2)/Ag can generate more reactive oxygen species for bacterial inactivation on the surface of electronic screens.More importantly,the TiO_(2)/Ag film had great biocompatibility with/without light irradiation.The platform not only provides a more convenient choice for the traditional antibacterial mode but also has limitless possibilities for application in the field of billions of touch screens.

Expert consensus on management principles of orthopedic emergency in the epidemic of coronavirus disease 2019

Since December 2019,many patients in Wuhan sustained pneumonia with unknown causes.[1,2]A part of severe patients developed acute respiratory distress syndrome or septic shock,and even death.On January 7,2020,Chinese researchers have for the first time detected a new coronavirus.On January 20,2020,the National Health Commission issued Announcement No.1 of 2020,which included the new coronavirus pneumonia as a Class B infectious disease,and conducted epidemic prevention and control according to the Class A infectious disease.This new kind of pneumonia has been named coronavirus disease 2019(COVID-19).The sixth edition of"Diagnosis and Treatment Scheme for New Coronavirus Infected Pneumonia"points out that the main transmission routes include respiratory droplets and close contact transmission.There is a possibility of aerosol transmission in a relatively closed environment with prolonged exposure to high concentrations of aerosol.New coronavirus pneumonia has a certain incubation period.