Objective To compare accuracy and surgery time between C-arm X-ray and 3D-CT in guiding thoracolumbar pedicle screw fixation.Methods98 and 104 pedicle screws were placed under the guidance of C-arm X-ray and 3D-CT respectively.Record the surgery time and after the operation,the position of the pedicle screw was evaluated with CT using the Richter grading system.ResultsGuided by C-arm X-ray navigation,accuracy of pedicle screw placement was 96.9% and surgery time was (75.0±15.0)min;with the guidance of 3D-CT,accuracy was 100%(P>0.05) and surgery time was (101.5±21.0) min(P<0.01).ConclusionsC-arm X-ray and 3D-CT navigation system both can accurately guide the thoracolumbar pedicle screw implants.However,the surgery time was longer under the guidance of 3D-CT because the operation was more complex.

Objective To discuss the clinical application of preserving femoral neck in total hip arthroplasty and to operative experience.Methods From January 2002 to Febuary2007,12 patients underwent total hip arthroplasty with preservation of femoral neck.We cut off the femoral head in infra-head position with Gibson incisions to reserve intact neck of femur.Then suitable size of extra cup was selected and placed at 55°eversion angle.The internal cup,made from ultra high polymer poly thene and with ultra radius design,was placed at 45°eversion angle.Harris scores were recorded before operation,after operation and during the follow-up.During the follow-up,the X-ray films were taken to assess position,loosening of the prosthesis and ectopicossification.Results All 8 patients were followed up 1～4 years.13 cases of total hip arthroplasty with femoral neck preservation is good.The mean Harris score of hip elevated from 50 scores before operation to 91 scores of the last follow-up.The X-ray films were not taken to assess position,loosening of the prosthesis and ectopicossification.There was no prosthesis loosening and femoral prosthesis setting.Conclusion Total hip arthroplasty with femoral neck preservation is a good option for the patients who need total hip arthroplasty for variable reasons,which is indicated for the patients whose femoral neck is intact with no osteoporosis.

Objective To assess the accuracy of computer navigation technology used in thoracolumbar pedicle screw fixation.Methods 15 cases with thoracolumbar lesions underwent orthopaedic operations.72 pedicle screws were inserted with the computer navigation.After the operation,the position of the pedicle screw was evaluated with CT and X-ray using the Richter grading system.Results All cases succeeded with assistance of computer navigation.15 cases were followed up for 6 to 24 months.No pedicle screw loosening or breakage was found.According to the location of the screw in X-ray and CT results,there was no vessel,nerve or spinal cord complication.According to Richter grading system,the results were excellent in 68 cases(94.4%) and good in 4(5.6%).It obviously reduced the radiation exposure to C-arm fluroscopy and the time that spend on surgery.It obviously improved the success rate of surgery.Conclusions C-arm navigation can obviously reduce error in thoracolumbar pedicle screw fixation and improve the accuracy of it.

Objective To discuss microinjury percutaneous reducution by strike with hand and fixation with round pins to SandersIV fracture of calcaneus.Methods Among 18 cases with calcaneus fractures.29 calcaneus fractures were treated by strike with hand and fixation with round pins and followed up for 17.2 months.Results According to Maryland foot score system.14 cases were excellent,4 cases were good.Conclusion Microinjury percutaneous reducution by strike with hand and fixation with round pins is a good method for treating crush fracture of calcaneus.

目的:探讨三维CT导航系统在胸腰椎椎弓根螺钉内固定中的应用价值.方法:三维CT导航系统辅助下.对导航组13例患者植入胸腰椎椎弓根螺钉65枚,其中胸椎骨折4例、腰椎骨折7例、腰椎滑脱症2例;在x线透视下对传统组14例患者植入胸腰椎椎弓根螺钉70枚,其中胸椎骨折3例、腰椎骨折7例、腰椎滑脱症2例、腰椎间盘突出症2例.术后均行CT扫描,按Richter分类法评估螺钉的位置.结果:术后按Richter分类法评估,导航组螺钉位置优62枚(95.4%),良3枚(4.6%),差0枚;传统手术组优57枚(81.4%),良10枚(14.3%),差3枚(4.3%).两组置钉准确性差异有统计学意义(P＜0.05).两组术后均无神经、脊髓损伤.24例随访0.5-1.0 a,复查X线片和CT.无螺钉松动和断裂钉,无迟发性脊髓损伤.结论:三维CT导航系统可以准确引导胸腰椎椎弓根螺钉的植入,手术精度高,并发症少.