BACKGROUND: Biomechanics of bone in vivo is concerned by the scholars who work for orthopaedic and medical bioengineering all the time. The application of strainmeter in this measurement has been studied for many years, but the long-term and successive measuring problems have not been solved. A new installing method for analyzing biomechanics of bone in vivoshould be considered to be explored. OBJECTIVE: To investigate the biochemical change of external fixator at both external and internal medullary cavity of anxial compressing fracture end invivo when external fixator is used DESIGN: Randomized and controlled animal experiment SETTING: Laboratory of Orthopaedic Department, Renmin Hospital, Wuhan University MATERIALS: Totally 18 healthy white rabbits, of rather gender, with the body mass of 3.6 to 4.2 kg , were chosen. METHODS: This experiment was conducted at the laboratory of Or thopaedic Department, Renmin Hospital, Wuhan University in November 2004. The chosen 18 healthy white rabbits were randomly divided into 2groups. External measuring group (Group A): the strain guage was affixed to the tibia external cortex by 502 gauge. Internal measuring group (Group B): strain guage coated with bone cement was installed on the tibia internal cortex. Group A and Group B were divided into two subgroups A1, A2 and B1, B2, respectively according to the pressure 0.5 time body mass and 1 time body mass. Strain voltage change and attenuation coefficient after compressing were measured with scaler. Statistical comparison was performed among the groups. MAIN OUTCOME MEASURES: ① The data of scaler curve. ② Attenuation coefficient of different compressions.RESULTS: ① The scaler curves of Group A changed greatly during early stage. After reaching stable stage, trendline of internal and external cortex went consistent but the former value was higher than that of the latter . The time of compression reaching stable was shorter in the Group B than in the Group A, and the absolute value of strain was smaller in the Group B than in the Group A. ② Before reaching stable after compression, the attenuation coefficient was low in the Group A1 as compared with Group A2. There was the same result between Group B1 and Group B2 group. When comparison was conducted between Group A and Group B, the curve of Group A decreased firstly, then ascended, but there was no ascending tendency in the Group B. After reaching stable, there were descending tendency in the Group A1 group and Group A2. It descended fast in the Group A2, while it kept at normal level in the Group B1 group. Fluctuation appeared in the Group A2. CONCLUSION: Strain of external medullary cavity is significantly larger than that of internal medullary cavity. It is easier to reach stable in the inter nal medullary cavity than in the external medullary cavity. 0.5 time of body mass is suitable at the initial period in treating fracture with external fixator.

Objective To compare the infection free and overall survival between first and subsequent tunneled cuffed hemodialysis catheters in geriatric patients.Methods The study involved57 geriatric patients [32 male,25 female; mean age (72.4 ± 6.7) years]undergoing maintenance hemodialysis in our blood purfication unit over a period of 72 months.Among a total of 131 catheters and 2686 catheter months including 57 first catheters and 74 consecutive catheters,48 wire guided exchange (WGE) and 26 removal and replacement (RAR),55/131 (42.0％) catheters were exchanged because of catheter-related bacteremia (CRB),37131 (28.2％) exchanged because of malfunction or cuff extrusion,39 /131 (29.9％)catheters were removed electively or was still functional at the end of the study period.Results One-year survival rates for first and consecutive catheters were 35.8％ and 28.4％,respectively.There was no difference in the overall survival between first catheters group and subsequent catheters group [(29.8±7.9)months vs.(28.7±6.0)months,t=0.711,P=0.443].However,infection free survival of first catheters group was significantly prolonged in comparison with that of subsequent catheters group [(13.1 ± 3.5) months vs.(11.6±2.7) months,t =2.415,P=0.018].The overall and infection-free survival in WGE group were not different with those of RAR group [(28.2 ± 7.2 ) months vs.( 28.5 ± 5.8 ) months,(11.1±3.1)months vs.(12.2±2.1)months,t=-0.163,0.103,P＞0.05].The infection free survival of first catheters group and WGE group was prolonged in comparison with that of in situ group[(13.1±3.5)months and (11.1±3.1)months vs.(8.2±2.1)months,t =7.602,5.601,P＜0.05].Conclusions WGE is safe and effective in the elderly patients if the tunnel and the exit site are not infected and has the potential benefit of preserving the vascular access site.

Objective To compare the therapeutic results of laparoscopic and open treatment for choledocholithiasis. Methods A prospective comparison was conducted between 29 cases of laparoscopic choledocholithotomy and 35 cases of open choledocholithotomy in terms of stone removal,operative time,hospitalization day,hospitalization cost and postoperative complications. Results Stone removal was achieved in 28/29 patients by a laparoscopic approach and in 32/35 patients by a open approach( ? 2=0 71, P =0 399);average operative time was (178 3?32 4) min in laparoscopic approach and (145 8?27 1)min in open approach( t =4 27, P =0 01);the patients in laparoscopic procedures had flatus in (20 8?2 9) hour and those in open procedures did in (58 2?4 9) hours( t =37 8, P 0 05);no major complication was found in laparoscopic approach. Conclusions Laparoscopic choledocholithotomy is safe and effective and it is superier to open treatment.

Abdominal aortic aneurysms(AAAs) is the most common aneurysm,and usually characterized by less symptom.While ruptured AAAs leads to high mortality.Abdominal ultrasonography can effectively detect AAA,decrease the AAAs-related mortality.However,screening AAAs causes some adverse outcomes,including psychological distress and immediate harms in treatment.Meanwhile,the prevalence of AAAs in sex and age is significantly different.Therefore,a reasonable and effective screening strategy is very important.This article search random control trials,systematic reviews,meta-analysis and guidelines in screening AAAs to obtain a reasonable screening strategy.

BACKGROUND: Vertebral reconstruction is stil a chal enge for spinal surgeons. Ideal reconstruction materials should have good osteogenesis ability, reliable support performance, low price and simple operating steps.
OBJECTIVE:To investigate the effect and feasibility of al ogenic cortical ring packed with autogenous cancellous bone in the reconstruction of rabbit cervical vertebra defect.
METHODS:Cervical vertebra defect models were established by resection of the fourth cervical vertebra in rabbits. Frozen-dried humeral cortical ring of rabbits was made to prepare the al ogenic cortical ring which was packed with autogenous cancellous bone. Then, al ogenic cortical ring packed with autogenous cancellous bone, single al ogenic cortical ring and autogenous iliac bone were used to repair rabbit cervical vertebra defects.
RESULTS AND CONCLUSION:The X-ray, histopathological examination, and scanning electron microscope examinations al showed that the bone union was most significant in group reconstructed with al ogenic cortical ring packed with autogenous cancellous bone. The alkaline phosphates activity in serum was higher in groups reconstructed with al ogenic cortical ring packed with autogenous cancellous bone and with autogenous iliac bone than in group reconstructed with only al ogenic cortical ring at 2 and 4 weeks after operation (P<0.01), but there was no difference between the former two groups. The biomechanical examination showed that the stability of al ogenic cortical ring packed with autogenous cancellous bone was higher than that of autogenous iliac bone at 1 month after operation (P<0.01). These findings indicate that the effect of al ogenic cortical ring packed with autogenous cancellous bone in the reconstruction of rabbit cervical vertebra defects is satisfactory, with a good biocompatibility, which is a promising method for the reconstruction of vertebral defects.

BACKGROUND: Many scholars adopt allograft interbody fusion for vertebral body resection and reconstruction, bone fusion time is better than autologous bone graft's, and its integration provides an early support and stabilizing, but the preparation of allogeneic bone graft material is easy to destroy b0ne-inducing factor in matrix, which is not conducive to bone growth. OBJECTIVE: To innovatively design and verify the ability of reconstructing rabbit cervical vertebrae with the compound of humeral cortical ring allograft (HCA) packed with red bone marrow (RBM) and autogenous cancellous bone (ACB). DESIGN, TIME AND SETTING: Randomized controlled animal experiment was performed at the laboratory of Orthopedic Department in Renmin Hospital of Wuhan University, between October 2004 and March 2006. MATERIALS: Sixty healthy adult New Zealand white rabbits, of either sex, body mass of 2.0-2.5 kg, were involved in this study. Twelve rabbits were used for HCA preparation, while the remaining 48 rabbits were randomly divided into 3 groups with sixteen rats in each group. Autologous RBM was extracted from the anterior superior lilac spine through puncture; ACB was obtained from td-cortical bone of rabbit iliac crest. Autologous RBM and ACB were compounded and filled in the self-made HCA. METHODS: Models of the fourth cervical vertebrae defect were created by surgery to simulate tumor resection in New Zealand white rabbits, which were divided into 3 groups randomly. Combined transplant group was treated with the compound of RBM+ACB+HCA; autologous bone transplant group with autogenous lilac crest; HCA transplant group with HCA. MAIN OUTCOME MEASURES: Vertebral reconstructions were evaluated by X-ray, histopathological observation and scanning electron microscope, as well as measurement of serum alkaline phosphates at different periods postoperatively. RESULTS: Eight weeks post-surgery, graft materials fused with the upper and lower cervical fusion, a large number of bone callus were observed in combined transplant group and autologous bone transplant group; HCA transplant group was present with a small amount of callus growth and poor fusion. Serum alkaline phosphatase levels were elevated in all groups, significantly higher in combined transplant group and autologous bone transplant group compared with HCA transplant group (P < 0.01 ). There were no significant differences of serum alkaline phosphatase levels between combined transplant group and autologous bone transplant group at 4 weeks or among 3 groups 8 weeks (P > 0.05). Histological analysis exhibited numerous mature bone matrix, bone trabecula and bone marrow cavity formed in combined transplant group and autologous bone transplant group. Scanning electron microscopy showed that many new bone formations in combined transplant group and autologous bone transplant group.CONCLUSION: The compound of RBM+ACB+HCA and autogenous lilac crest transplantation can efficiently reconstruct cervical vertebrae, RBM+ACB can improve the reconstruction efficiency of HCA, and could use as a matedal in cervical reconstruction.

Objective To explore the value of E-Tracking technique in evaluating the vascular endothelial function of carotid artery in subclinical hypothyroidism.Methods The study population include 38 subclinical hypothyroidism patients and 60 normal controls.E-Tracking technique was performed to track the movements of the common carotid artery and the following parameters were assessed:stiffness parameter(β),elastic coefficient (Ep),arterial compliance (AC),augment index (AI) and one point pulse wave velocity (PWVβ).Results Ep,β,AI and PWVβ were significantly higher in subclinical hypothyroidism than those in the control group,AC were lower than that in the control group( P ＜0.05).Conclusions Vascular endothelial function in subclinical hypothyroidism patients is injured in early stage.ETracking technique may conduce to find the injury early and may assess it quantitatively.

Objective To evaluate the effect of gender matching on the outcomes of livingdonor renal transplantation.Methods A total of 419 cases of living-donor renal transplantation in our center were divided into male-donor-male-recipient (MDMR) group,male-donor-female-recipient (MDFR) group,female-donor-male-recipient (FDMR) group,female-donor-female-recipient (FDFR)group.The outcomes including graft and patient survival,acute rejection and renal function were analyzed retrospectively.Results Compared to MDMR group,MDFR group and FDFR group had lower Scr [(80.7±17.9),(87.4±21.9) μmol/L vs (120.3±72.5) μmol/L,all P ＜ 0.05] and uric acid (UA) [(318.1 ± 86.4),(303.5 ± 66.9) μmol/L vs (358.4 ± 77.8) μmol/L,P ＜ 0.05] 6 months after operation.Compared to MDFR group,FDMR group had higher Scr[(117.7±27.4) μmol/L vs (80.7±17.9) μmol/L,P ＜ 0.01],UA [(371.0±92.4) μmol/L vs (318.1±86.4) μmol/L,P ＜ 0.05] and lower glomerular filtration rate (GFR) [(70.4± 17.8) ml/min vs (79.6± 18.9) ml/min,P ＜ 0.05].Compared to FDMR group,FDFR group had lower Scr [(87.4±21.9) μmol/L vs (117.7±27.4) μmol/L,P ＜ 0.01] and UA [(303.5±66.9)μmol/L vs (371.092.4) μmol/L,P＜ 0.01].Compared to MDFR group,FDFR group showed lower GFR [(72.4±25.3) ml/min vs (82.7± 18.7) ml/min,P ＜ 0.05] 1 year after operation.Compared to MDMR group,FDFR group showed lower UA [(322.9±69.7) μmol/L vs (376.0±66.2) μmol/L,P ＜ 0.05] 2 years after operation.Compared to FDMR group,FDFR group showed lower Scr [(88.7 ±27.0) μmol/L vs (112.7±27.8) μmol/L,P ＜ 0.05] and UA [(318.3 ±61.2) μmol/L vs (396.2± 100.3) μmol/L,P ＜ 0.05] 3 years after operation.5 years after operation,there were no significant differences in above indexes,the incidence of slow graft function,acute rejection and survival of graft and patient among groups.Conclusions Male recipients of female donors have the worst renal function while female recipients have better outcomes after operation.

Objective To investigate the types and outcome of vascular access in patients with end stage renal disease (ESRD) initiated hemodialysis (HD), and provide the basis for advancing the proportion of planned HD with arteriovenous fistula (AVF). Methods Clinical data, vascular access types at the initiation of HD, the outcomes of all types of dialysis access and the conversion of renal replacement therapy of ESRD patients who initiated HD in the first affiliated hospital of zhejiang university between January 2009 and December 2011 were retrospectively studied. Results A total of 836 patients were included in our study. Among them 510 were males and 326 were females. The average age was (49.77 ± 17.65) years old. The major primary diseases were primary glomerular disease (72.73%), diabetic nephropathy (11.60%)and hypertensive nephrosclerosis (3.95%). Only 73 patients (8.73%) used AVF as the vascular access at the initiation of HD, another 763 patients (91.27%) used central venous catheter. Six months after the start of dialysis, 542 patients (81.5%) had used AVF as permanent vascular access, 123 patients (18.5%)had used the tunneled cuffed catheter, 54 patients had received a transplant and 55 patients had converted to peritoneal dialysis. The results of logistic regression analysis suggested that being male, patients from outside hangzhou and patients whose glomerular filtration rate were lower than 5 ml·min-1·(1.73 m2)-1 were the risk factors of using central venous catheters at the initiation of HD. Conclusions Only a minority of patients used AVF at the initiation of HD, but most of the other patients switched to AVF within the following six months. Increasing the proportion of AVF as the vascular access of planned HD is still our current goal.

Objective To discuss the clinical value of procalcitonin (PCT) in guiding antibiotics use in children with severe diseases. Methods The clinical data of patients admitted to intensive care unit from January 2012 to July 2012 were retrospectively analyzed. The patients without antibiotics use before admission and with procalcitonin level less than 0.5 ng/ml on admission were selected. The body temperature, infection indicators and prognosis were compared between patients with and without antibiotics use during hospitalization. Results There was no difference in body temperature, PCT, C-reactive pro-tein (CRP), erythrocyte sedimentation rate (ESR) and white blood cell count (WBC) on admission between patients with and without antibiotics use during hospitalization. The PCT level was increased signiifcantly (P<0.05) on the day of starting the an-tibiotics when compared with that on admission in 60 patients while there was no change in the levels of WBC and CRP. Com-pared with the day of starting the antibiotics, body temperature declined (P<0.05) and PCT level in 56 patients reexamined was decreased (P<0.05) at 3 days after antibiotics use. Two hundred and eleven patients (98.14%) had favorable prognosis. Conclu-sions Monitoring PCT can guiding the clinical use of antibiotics.