1.Three-dimensional finite element model of calcaneus and talus during different gait phases
Academic Journal of Second Military Medical University 2001;0(09):-
Objective:To establish a 3 dimensional finite element model of calcaneus and talus for analysing their stress distribution during different gait phases. Methods: CT scanning and computer image processing system were used to establish the model to simulate the situation of calcaneus and talus for 3 phases (heel strike, midstance, push off) during the gait. A finite element solver was used to calculate stress. Results: A three dimensional finite element model of calcaneus and talus was established. And the stress distribution within the bone was obtained and regions with elevated stress at 3 phases were located. The stress distributions of 3 phases were significantly different. The stress increased gradually from heel strike to push off. Conclusion:The model can be used to study biomechanics of calcaneus and talus. The regions of elevated stress of calcaneus and talus are important, which provide an insight into the factors contributing to the fractures and arthritis.
2.Post-traumatic osteomyelitis
Lifeng LIU ; Lin ZOU ; Jinfang CAI
Orthopedic Journal of China 2006;0(10):-
Post-traumatic osteomyelitis is painful and challenging disease.High success rate of antimicrobial therapy in most cases has not been achieved in skeleton due to its physiological and anatomical characteristics.The key to successful management is early diagnosis and treatment.Different types of post-traumatic osteomyelitis require different medication and different surgical therapeutic strategies.Post-traumatic osteomyelitis is associated with avascular necrosis of bone and formation of sequestrum(dead bone).Surgical debridement is necessary in addition to antibiotic therapy.Generally,multidisciplinary techniques are required,including orthopaedic surgery,plastic surgery,as well as vascular surgery,especially for complex cases with soft-tissue defect.
3.STRESS ANALYSIS OF THREE-DIMENSIONAL FINITE ELEMENT MODEL OF CALCANEUS WITH COMPRESSION OF POSTERIOR FACET AFTER FACTURE AND TALUS DURING GAIT
Lifeng LIU ; Jinfang CAI ; Jin LIANG ;
Medical Journal of Chinese People's Liberation Army 2001;0(11):-
Objective To analyze the stress distribution of calcaneus and talus with posterior facet after compression fracture during gait by finite element method. Methods A wedge was resected to simulate the malunion calcaneus with compression fracture of posterior facet. The Bo?hler’s angle was reduced from 35? to 10?. The calcaneus and talus malunion were used to simulate for three phases of the stance during the gait (heel strike, midstance, push off). A finite element solver to calculate. The results were compared with normal condition. Results The stress distribution within the bone in condition of malunion was obtained, and sites of enhanced stresses for three phases were located. The results were significantly different from that of normal condition. Conclusion The results revealed the importance of reconstruction of calcaneal structure and helped us understand the cause of sequela of calcaneal fractures
4.The efficacy of the combination of improved intramedullary VSD drainage and contained antibiotics bone graft to treat chronic tubular bones osteomyelitis
Xiaobin CAI ; Lifeng SHEN ; Yinan LAN ; Chun ZHANG ; Jian LI
Chinese Journal of Microsurgery 2015;38(3):248-253
Objective To investigate the efficacy of the combination of improved intramedullary VSD drainage and contained antibiotics bone graft to treat chronic tubular bones osteomyelitis.Methods From March,2011 to December,2013,our department have total of 40 patients with chronic tubular bones osteomyelitis.Twenty cases (group A) treat with one-stage osteomyelitis debridement cortical bone slotted,contained antibiotic bone and autologous bone implants and wound repair.Twenty cases (group B) treat with improved intramedullary VSD drainage 3-5 days temporarily after osteomyelitis debridement cortical bone slotted,then contained antibiotic bone and autologous bone implants and wound repair.A retrospective comparison of two groups of an average residence time of wound drainage postoperative,bone bed bacterial culture positive rate,average healing time,the average time of hospital stay,the average bone healing time,and recurrence rate of osteomyelitis.Statistical analysis with T test was used for above independent parametric.Results The two groups were followed-up for 6-24 months,independent samples t-test was used for two groups in the wound healing time,bone healing time,the drainage tube removal time and the length of hospital stay,in group A bone bed bacteria culture positive rate was 40%,group B was 5%,group A infection relapse has 2 cases,1 case was debridement cured,1 case was amputation,and the recurrence rate of 10%.Group B without infection recurrence,and the recurrence rate of 0% ; The healing time and hospital stay of intramedullary drainage surgery patients (18.05 ± 2.74 d and 22.65 ± 2.80 d,respectively,in group B) was significantly less than one-stage surgery patients (24.10 ± 8.20 d and 28.10 ± 9.35 d,respectively,in group A),but the bone healing time and the drainage tube removal tine of two groups.There was no significant difference (P > 0.05).Conclusion Contained antibiotic bone and autologous bone implants with wound healing therapy after osteomyelitis debridement cortical bone slotted with improvement VSD intramedullary drainage to treat patient with tubular bones osteomyelitis was more effective,it worthy of clinical spread.
5.The Evaluation of Earlier Diagnosis and Follow-up on Bleeding and Necrotizing Pancreatitis by Ultrasound
Zhuangwei CAI ; Lifeng DU ; Changyun ZHANG ; Jiankang LUO
Journal of Practical Radiology 2001;0(10):-
Objective To evaluate the value of early diagnosis and follow-up of bleeding and necrotizing pancreatitis by ultrasound.Methods 52 cases with bleeding and necrotizing pancreatitis confirmed by operation and pathology were examined by ultrasound. The pancreas were observed section by section in the blood vessel surrounding the pancreas acted as the mark under reduced the influence of gas in gastro-intestine and using adopting protruding probe with high resolution and compounding scanning technique in multi-posture. Results The accurate rate of diagnosis by ultrasound was 92%(48/52).During the follow-up period, pseudocysts and other complications were found in 9 cases, all cases recovered gradually after operations and treatment of symptoms except 3 cases who died caused by complications such as multiple organ dysfunction. Conclusion Ultrasound can identify bleeding and necrotizing pancreatitis early and also can regard as a significant follow-up method.
6.Treatment of humerus nonunion using lilac bone graft limited internal fixation combined with external fixation in 13 cases
Hailei YIN ; Jinfang CAI ; Lifeng LIU ; Zongyu LI
Chinese Journal of Tissue Engineering Research 2010;14(4):714-717
BACKGROUND: There is lack of effective method for treating humerus nonunion, lilac plate can maintain the compact contact between fracture end and bone graft, accelerate bone union, as well as provide stability for bone union. OBJECTIVE: To evaluate the clinical effects of treating humerus nonunion by using lilac bone graft as plate combined with the external fixation.METHODS: Thirteen patients with nonunion of the humorous at Department of Orthopedic Trauma Surgery, Jinan Command General Hospital of Chinese PLA were selected, including 11 males and 2 females, aged 20 51 years, mean aged 35.5 years. All the patients were treated with Uiac bone graft and screws combined with the mono lateral external fixation. The bone healing was observed by X-ray film. Shoulder function and complications were measured by Neer score.RESULTS AND CONCLUSION: All patients were followed up for 7-64 months, mean 38 months. Bony union was achieved in all patients within 6-10 months (mean 8.1 months). The activity function of shoulder and elbow was normal; and Neer scores were 71-96 (mean 87 scores). No infection, pain, prevalent fracture or nonunion occurred. The results demonstrated that using lilac bone graft as plate combined with the mono lateral external fixation is a good salvage operation for nonunion of the humerus.
7.Treatment of nonunion of tibial fractures with local muscle flap transfer and injection of autogenous bone marrow
Ruimin WANG ; Yaozhong WANG ; Lei ZHAO ; Zhidong WANG ; Lifeng CAI
Chinese Journal of Orthopaedic Trauma 2004;0(05):-
Objective To report the treatment outcome of nonunion of tibial fractures with local muscle flap transfer and injection of autogenous bone marrow. Methods 15 patients who had suffered from nonunion of tibial fracture 10 to 42 (mean 22) months after the initial injury underwent open reduction, internal fixation with locking intramedullary nail, wound coverage with locally transferred muscle flap and injection of autogenous bone marrow into the fracture site 12 to 15 days after operation. Results The follow-ups revealed bone union in all the cases of this series with a mean healing time of 22 (3 to 11) months. Except for limited necrosis of the skin edge in 2 cases which healed after dressing changes, the wounds healed primarily in all the cases without infection and implant failure. Conclusion Besides stable internal fixation and bone graft, coverage of fracture site with locally transferred muscle flap and injection of autogenous bone marrow can be used to treat nonunion of tibial fractures with satisfactory results.
8.Distal pedical fibular osteoseptocutaneous flap transfer for the lateral forefoot defect
Zongyu LI ; Jinfang CAI ; Hailei YIN ; Yidong CUI ; Lin ZOU ; Jinlong ZHENG ; Lifeng LIU ; Xuecheng CAO
Chinese Journal of Microsurgery 2010;33(6):454-456,后插4
Objective The anterior-lateral defect of foot that lost one of the three supporting point of foot can lead to collapse of the lateral longitudinal arch, overload of the first metatarsal heads, and painful callus formation. It is meaningful to investigate the effect of reconstructing the lateral forefoot defect with pedical fibular osteoseptocutaneous flap. Methods From March 1989 to June 2008, there were 38 patients with anterior-lateral defect of foot were constructed. The supporting point with the local distal based pedical fibular osteoseptocutaneous flap was constracted. Results All the 38 flaps survived. All 38 patients had been followed up from 6 months to 10 years (mean 23.5 months) postoperatively. The constructed supporting point of the foot was functional. The patients could walk freely with no pain, and was satisfied with the operation. Assessed with the rating system for foot and ankle established by the American Orthopaedic Foot And Anke Society, 8 patients got a score above 85, 23 patients between 75 to 85, 7 patients between 60 to 75. Conclusion It is effective that transferring local distal based pedical fibular osteoseptocutaneous flap to repair the anterior-lateral defect of foot.
9.Use of cross-leg fibula flap for difficult reconstruction of extensive injuries in the lower extremities
Lin ZOU ; Jinfang CAI ; Lifeng LIU ; Jun ZHANG ; Jinlong ZHENG ; Xuecheng CAO
Chinese Journal of Orthopaedics 2012;32(7):675-680
Objective To study clinical outcomes of cross-leg fibula flap for difficult reconstruction of an extensive injury in the lower extremity,which included large soft-tissue defects and long infected bone and tibia defects combined with vascular injury.Methods From September 2004 to September 2008,8 cases with an extensive injury in the lower extremity,which included large soft-tissue defects and long infected bone and tibia defects with vascular injury,were retrospectively analyzed,including 6 males and 2 females with an average age of 36 years (range,19-55 years).The course of disease ranged from 2 weeks to 3 months (average,2 months).The bone defect length ranged from 8 to 20 cm (average,13 cm),and the skin defect area varied from 10 cm×7 cm to 22 cm×12 cm.After thorough debridement,cross-leg fibula flap was used to repair the tibial defect and concomitant soft tissue defect.The pedicles were divided at 4-6 weeks after the initial surgery.The important technical considerations were outlined.Results All 8 patients were followed up for 6 to 36 months (average,24 months).The flaps survived in all 8 patients,and no infection and osteomyelitis happened.The flap transplantations healed at two weeks after operation with good shape.The fractures healed in all of patients with an average period of 11 months (range,6-15 months).All of patients recovered to walk without aid.According to Edwards classification of tibial fractures,4 cases were classified as good,2 as acceptable,and 2 as poor.Conclusion The cross-leg fibula flap is relatively simple,liable for the treatment of an extensive injury in the lower extremity.
10.Residue and Degradation of Cyantraniliprole and Its Main Metabolite in Pepper and Soil
Hongmei HE ; Chunrong ZHANG ; Yahong ZHU ; Changpeng ZHANG ; Lifeng PING ; Hua ZHAO ; Min WU ; Tao TANG ; Xiaoming CAI ; Zhen LI
Chinese Journal of Analytical Chemistry 2014;(8):1178-1183
An analytical method based on ultra performance liquid chromatography-tandem mass spectrometry was developed for the determination of cyantraniliprole and its main metabolite J9 Z38 residues in pepper and soil. The fate of cyantraniliprole and J9Z38 in pepper and soil was also evaluated. The target compounds were extracted with acetonitrile, cleaned up by C18 cartridge, and further analyzed by gradient ultra performance liquid chromatography-tandem mass spectrometry with electrospray ionization in positive mode ( ESI﹢) using a UPLC BEH C18 Column. The method was validated using fortified pepper and soil. Intra-day mean recoveries of cyantraniliprole and J9Z38 at three spiked levels (0. 01, 0. 10 and 1. 00 mg/kg) ranged from 88. 6% to 105 . 7% with relative standard deviations of 3 . 8%-15 . 1%. Inter-day mean recoveries of cyantraniliprole and J9 Z38 were found between 91 . 4% and 105 . 3% with relative standard deviations of 4 . 9%-12 . 3% at three spiked levels. Limits of quantification ( LOQs) of cyantraniliprole and J9Z38 were 0. 1 and 0. 2 μg/kg, respectively. Linear calibration functions with correlation coefficients of r>0. 9992 were obtained in the concentration range of 2. 0-128. 0 μg/L. This method was applied to the analysis of cyantraniliprole and J9Z38 residues in real pepper and soil samples selected from field. The results of the residue dynamic experiment showed that the half-life of cyantraniliprole ranged from 9 . 2 to 11 . 2 days in pepper and from 9 . 2 to 20. 8 days in soil. While, the residues of J9Z38 in pepper were below LOQ, and the half-life of J9Z38 in soil was 9. 4 days. The degradation speed of cyantraniliprole increased with the increase of the precipitation.