Position and complications of pedicle screw insertion with or without image-navigation techniques in the thoracolumbar spine:a meta-analysis of comparative studies

Computer-navigated pedicle screw insertion is applied to the thoracic and lumbar spine to attain high insertion accuracy and a low rate of screw-related complications.However,some in vivo and in vitro studies have shown that no advantages are gained with the use of navigation techniques compared to conventional techniques.Additionally,inconsistent conclusions have been drawn in various studies due to different population characteristics and methods used to assess the accuracy of screw placement.Moreover,it is not clear whether pedicle screw insertion with navigation techniques decreases the incidence of screw-related complications.Therefore,this study was sought to perform a meta-analysis of all available prospective evidence regarding pedicle screw insertion with or without navigation techniques in human thoracic and lumbar spine.We considered in vivo comparative studies that assessed the results of pedicle screw placement with or without navigation techniques.PubMed,Ovid MEDLINE and EMBASE databases were searched.Three published randomized controlled trials（RCTs） and nine retrospective comparative studies met the inclusion criteria.These studies included a total of 732 patients in whom 4,953 screws were inserted.In conclusion,accuracy of the position of grade I,II,III and IV screws and complication rate related to pedicle screw placement were significantly increased when navigation techniques were used in comparison to conventional techniques.Future research in this area should include RCTs with well-planned methodology to limit bias and report on validated,patient-based outcome measures.

Intracortical screw insertion plus limited open reduction in treating type 31A3 irreducible intertrochanteric fractures in the elderly

BACKGROUND In most elderly patients with intertrochanteric fractures,satisfactory fracture reduction can be achieved by closed reduction using a traction table.However,intertrochanteric fractures cannot achieve satisfactory reduction in a few patients,which is called irreducible intertrochanteric fractures.Especially for type 31A3 irreducible intertrochanteric fractures,limited open reduction of the broken end with different intraoperative reduction methods is required to achieve satisfactory reduction and fixation.AIM To discuss clinical efficacy of intracortical screw insertion plus limited open reduction in type 31A3 irreducible intertrochanteric fractures in the elderly.METHODS A retrospective analysis was performed on 23 elderly patients with type 31A3 irreducible intertrochanteric fractures(12 males and 11 females,aged 65-89-yearsold)who received treatment at the orthopedics department.After type 31A3 irreducible intertrochanteric fractures were confirmed by intraoperative C-arm,all of these cases received intracortical screw insertion plus limited open reduction in the broken end with intramedullary screw internal fixation.The basic information of surgery,reduction effects,and functional recovery scores of the hip joint were assessed.RESULTS All patients were followed up for 13.8 mo on average.The operation time was 53.8±13.6 min(40-95 min).The intraoperative blood loss was 218.5±28.6 mL(170-320 mL).The average number of intraoperative X-rays was 22.8±4.6(18-33).The average time to fracture union was 4.8±0.7 mo.The reduction effect was assessed using Kim’s fracture reduction evaluation.Twenty cases achieved grade I fracture reduction and three cases grade II fracture reduction.All of them achieved excellent or good fracture reduction.Upon the last follow-up,the functional recovery scores score was 83.6±9.8,which was not significantly different from the functional recovery scores score(84.8±10.7)before the fracture(t=0.397,P=0.694).CONCLUSION With careful preoperative preparation,intracortical screw insertion plus limited open reduction contributed to high-quality fracture reduction and fixation.Good clinical outcomes were achieved without increasing operation time and intraoperative blood loss.

Experimental Study and Preliminary Clinical Application of Miniinvasive Percutaneous Internal Screw Fixation for Scaphoid Fracture under the Guidance of a 3D-printed Guide Plate

This study explored the feasibility of employing computer-aided design(CAD)and 3 dimensional(3D)-printed personalized guide plate for the mini-invasive percutaneous internal screw fixation of fractured scaphoid.The study consisted of two parts:(1)experimentation on upper limbs from corpses and(2)preliminary clinical application.Corpse experiments involved upper limbs of 6 adult corpses.The specimens of upper limbs were subjected to plain CT scan.Then the CT data were input into computer to conduct 3D reconstruction of wrist region.The direction and depth of the guide wire and screw were designed on the basis of the principle that screw should lie at the center of scaphoid and the long axis of the screw should be aligned with that of the scaphoid.The carpal bone model and the guide plate were designed and 3D-printed.By using the guide plates,the guide wire was placed and the cannulated compression screw was inserted.The wrist region was examined by X-ray and CT to observe the location of the screw in the scaphoid.The scaphoid was longitudinally excised to grossly observe the location and evaluate the result of screw insertion.For clinical application,the guide plate was employed in 4 patients with fresh scaphoid fracture using the aforementioned operative technique.Our results showed that,in the 6 corpse limbs,the guide plate well fitted the skin surface and the guide wire and screw were accurately put in place in one session.X-ray examination and gross observation confirmed that the screw was satisfactorily positioned and the result met the requirements of the preoperative design.For 4 patients,the guide wire and screw were all precisely inserted into place in one session.The operation time and X-ray exposure times were apparently reduced.The imaging examination exhibited satisfactory results and the hand functioned well.It was concluded that the operative guide plate used for the mini­invasive percutaneous internal screw fixation of fractured scaphoid not only can assist in accurate placement of screw but also shorten operation time and reduce insertion and X-ray exposure times,thereby reducing the radiation injury and damage to the substance and the blood circulation of carpal bone.Its use can also improve the learning curve of surgeons.