Objective To review computed tomographic angiography (CTA) signs and its potential use in the diagnose of blunt thoracic aortic injury Methods We reviewed 37 cases with blunt thoracic aortic injury (TAI) confirmed by surgery or aortography in Chinese PLA General Hospital emergency department from June 2004 to June 2014.CTA were performed on these patients,and CTA images were analyzed retrospectively to obtain characteristic CTA signs of blunt thoracic aortic injury.Results Of the 37 cases,the blunt injury in aortic isthmus were 83.8％ (31/37),aortic arch 5.4％ (2/37),descending aorta 8.1％ (3/37),and ascending aorta 2.7％ (1/37),respectively.CTA signs of thoracic aortic injury manifested as intimal flap in 34 patients (91.8％),abnormal aortic contour or cavity in 37 cases (100％),arterial contraction in 17 cases (45.9％),aortic dissection in 10 cases (27.0％),pseudoaneurysm in 21 cases (56.7％),thrombosis in 1 case (2.7％).Conclusions CTA signs could be used to facilitate the diagnosis of blunt thoracic aortic injury with a qualitative diagnostic value.

OBJECTIVE To determine the feasibility of clindamycin-loaded calcium phosphate cement(CLCPC) as a local antibiotic delivery system.METHODS The initial setting time(tI) and the final setting time(tF) were measured for 0%,2% and 5% CLCPC according to ASTM C266-89 method.Clindamycin concentrations eluting from the samples of 2% and 5% CLCPC in PBS were analyzed by HPLC at different times.The bacteriostasis tests were done by plate diffusion method for 2% and 5% CLCPC and 2% Palacos R-40 bone cement(PMMP) samples,and the diameters of the bacteriostasis ring and bacteriostasis duration were observed.The setting product and crystal size of 0%,2% and 5% CLCPC were analyzed and observed by X-ray diffraction(XRD) and scanning electron microscopy(SEM).RESULTS The setting time could be shortened by adding clindamycin(tI,tF) of 2% and 5% CLCPC.Clindamycin was with burst-release from CLCPC within the intial 6-hour period and the release rate slowed down on 4th day.Clindamycin could still release until to the 42th day.The ring of 2% Palacos R-40 bone cement(PMMP) bacteriostasis was smaller than that of 2% CLCPC,and the ring of 2% CLCPC bacteriostasis was smaller than that of 5%CLCPC.The bacteriostasis still existed to the 42th day of test for 2% and 5%CLCPC and 2% Clindamycin-loaded Palacos R-40 bone cement(CLPMMP).From the 30th day,many bacterial colonies were seen in the culture media laying 2%CLPMMP sample.On the contrary,bacterial colony was not found in the media putting 2% and 5%CLCPC.XRD and SEM showed that clindamycin did′t have an influence on setting product,crystal size and structure of CPC.CONCLUSIONS Clindamycin-loaded calcium phosphate cement can be used as a local antibiotic delivery system.

OBJECTIVE To establish the implanted biofilm model of rabbit implant infection.METHODS SEP was cultured,purified,identified,and tested for the drug sensitivity and the biofilm production.Healthy adult rabbits were randomly divided into 4 groups,8 in each group.The stainless steel screws and washer UHMWPEs were implanted into the femoral condyle of the non-articular surface of the rabbit right stifle knee.The knee joints were inoculated with 1ml sterile saline,102,103 and 104 CFU SEP,respectively.Wounds were observed postoperatively.After the 14th days postoperation,the knee synovium of 32 rabbits sacrificed were taken out by aseptic technique and were cultured to determine whether the knees were infected and which concentration of SEP was the appropriate for causing knee joint infection.UHMWPEs from the appropriate ID group were observed to find whether there were biofilms on the surface by SEM and LCSM.RESULTS The bacterial strain was identified as SEP and could produce biofilm.Among the knee joints inoculated with 1ml saline,102,103 and 104 CFU SEP,the infective rate was 0,37.5%,100.0% and 100.0% and poor wound healing was in 0,1,2 and 4 rabbits,respectively.It showed 103 CFU of SEP was the appropriate ID.Biofilms were found on all UHMWPE surfaces from 103 CFU SEP group by SEM and LCSM.SEM showed SEP in the biofilms on the surface of UHMWPE was agglomerated and wrapped in the matrix.The structure of biofilms in which SEP radiated red fluorescence was inlaid in mucopolysaccharide stained green fluorescence was observed by LCSM.CONCLUSIONS The model provides an effective method to investigate the biofilm.

OBJECTIVE To evaluate the diagnostic values of biochemical tests for infection before revision hip arthroplasty. METHODS One hundred and forty five cases with revision hip arthroplasty were reviewed.The diagnostic results of infected hip arthroplasty according to ESR,CRP and "gold standard" were compared. RESULTS ESR served as the diagnostic criterion of infected hip arthroplasty,its sensitivity,specificity,positive and negative predictive value,accuracy and Youden′s index were 57.89%,85.71%,37.93%,93.10%,20.00 and 0.44,respectively.CRP as the diagnostic criterion of infected hip arthroplasty,its sensitivity,specificity,positive and negative predictive value,accuracy and Youden′s index were 68.42%,88.89%,48.15%,94.92%,18.62 and 0.57,respectively. CONCLUSIONS Being routine tests before revision hip arthroplasty,ESR and CRP play a screening role in the diagnosis of infected hip arthroplasty and compliment each other so that the accuracy of diagnosis can be improved.

OBJECTIVE To investigate the in vitro effect of 4 kinds of implant materials on the biofilm formation of Staphylococcus epidermidis.METHODS S.epidermidis was cultured,purified and identified.Susceptibility test was done for S.epidermidis and the ability to produce biofilm was proven.The test samples were made into wafer shape for titanium alloy,Co-Cr-Mo alloy,ultrahigh molecular weight polyethylene(UHMWPE)and home-made polymethyl methacrylate(PMMA).S.epidermidis was cultured with 4 kinds of test samples for 5 days respectively.Bacteria adhering on surfaces of 4 kinds of test samples were dissolved with trypsin,and then diluted into bacterial suspensions.Each bacterial suspension was inoculated quantitatively and CFU were counted.Biofilm on surfaces of 4 kinds of test samples prepared by vacuum drying method was observed with SEM.RESULTS The strain proven to be S.epidermidis,was resistant to semisynthetic penicillins,and could produce biofilm.CFU count showed that CFU were the most on the UHMWPE surface and the number of CFU were(24.96?1.459)?105.CFU were(17.44?1.883)?105 on the PMMP surface.(0.424?0.065)?105 CFU were discovered on the surfaces of titanium alloy and(0.382?0.075)?105 CFU on Co-Cr-Mo alloy.When each group compared with UHMWPE and domestic PMMA respectively,all P value was