Objective To simulate the stress generated by contact with the femur during the assembly of novel semi-hip prosthesis, and discuss the operating limits and adaptive prosthesis profile in clinic. Methods CT scans were conducted on the proximal end of the femur in a male volunteer of 60 years old as a physical model. By transferring the CT data to finite element modeling software, the physical model was simplified, meshed, materialized and assembled with the model of prosthesis to establish the three-dimensional finite element model. Surface to surface contact relationship between the femur and the prosthesis was also constructed by utilizing contact elements. Relative sliding distance and stress distribution were solved while simulating the process of assembling the prosthesis. Results Additional stress was generated on the sudden change area of the contact surface when the prosthesis was seated. The greatest contact pressure came from the changing section of the ridge of the prothesis, and the maximum assembly stress and sliding distance range increased nonlinearly along with the pushing distance. The increase rate of additional stress was enhanced significantly while Δz≥0.5 mm. Conclusions Compared with the prosthesis without ridge, the prosthesis with ridge can be easily seated and obtain mechanical stabilization. However, the relevant clinical operating limits should be obeyed to avoid generating excessive additional stress during the implantation of prosthesis, which may cause treatment failure due to the damage in bone cortex.

Objective To develop a new hemi-arthroplasty system-Trochanteric Prosthesis System (TC) for the treatment of unstable femoral intertrochanteric fractures in the elderly, so as to preserve bone mass and meet requirement of functional exercises at early stage. Methods A normal male adult volunteer was chosen to receive CT scanning at middle and upper regions of his both intact femur. The serial digitized image data of spiral CT in DICOM format were imported to finite element modeling software to establish a three-dimensional (3D) solid model of the proximal femur. The Pro/E software was used to conduct computer-aided design of the new hemi-arthroplasty prosthesis system and then its metal model was also made by rapid prototyping techniques. After repeated verification and improvement on cadaver femur, the femoral prosthesis was molded and assembled in the solid fracture mode for finite element analysis. The unstable femoral intertrochanteric fracture model obtained from the fresh cadaver of an elderly male was chosen to make A2.2 Type of such fracture model in AO classification system. The new hemi arthroplasty prosthesis system was implanted and assembled into the model and received mechanical testing, including material performance testing, prosthesis head/neck and stem fatigue testing, anti-compression and anti-torsion testing, according to the National Industrial Standard YY0117 and YY0118. Results The sample of new hemi-arthroplasty prosthesis sustained 5 million cycle (8 Hz) fatigue testing on the part of the head-neck and the stem body without any breakage and failure. With the sample implanted into the intertrochanteric fracture model, the maximum compressive strength and torsional strength of the sample reached over 2 kN and 15.5 N•m without failure, respectively. The contact stresses between the stem and the femur were mostly distributed at the region below the femoral trochanter, where the maximum average Von Mises stress values were 17.6~26.4 MPa. Stresses at the region of intertrochanteric fractures were at a low level. The maximum average Von Mises stress values at the greater and lesser trochanter region were 2.7 and 4.9 MPa, respectively. Conclusions The new developed hemi-arthroplasty prosthesis has the advantages of easy performance, reliable fixation, sufficient bone preservation and it is capable of fulfilling the demands of early weight bearing and functional exercises. It is suitable for the treatment of unstable femoral intertrochanteric fractures in the elderly.

Due to the negative autopsy and without cardiac structural abnormalities, unexpected sudden cardiac death （USCD） is always a tough issue for forensic pathological expertise. USCD may be associated with parts of fatal arrhythmic diseases. These arrhythmic diseases may be caused by disorders of cardiac ion channels or channel-related proteins. Caveolin can combine with multiple myocardial ion channel proteins through its scaffolding regions and plays an important role in maintaining the depolarization and repolarization of cardiac action potential. When the structure and function of caveolin are affected by gene mutations or abnormal protein expression, the functions of the regulated ion channels are correspondingly impaired, which leads to the occurrence of multiple channelopathies, arrhythmia or even sudden cardiac death. It is important to study the effects of caveolin on the functions of ion channels for exploring the mechanisms of malignant arrhythmia and sudden cardiac death.
Arrhythmias, Cardiac/physiopathology* ; Autopsy ; Caveolins/metabolism* ; Channelopathies/genetics* ; Death, Sudden, Cardiac/pathology* ; Forensic Pathology ; Humans ; Ion Channels/metabolism* ; Mutation ; Myocardium

OBJECTIVES: To explore the genetic variation sites of caveolin （CAV） and their correlation with sudden unexplained death （SUD）. METHODS: The blood samples were collected from SUD group （71 cases）, coronary artery disease （CAD） group （62 cases） and control group （60 cases）, respectively. The genome DNA were extracted and sequencing was performed directly by amplifying gene coding region and exon-intron splicing region of CAV1 and CAV3 using PCR. The type of heritable variation of CVA was confirmed and statistical analysis was performed. RESULTS: A total of 4 variation sites that maybe significative were identified in SUD group, and two were newfound which were CAV1： c.45C>T （T15T） and CAV1：c.512G>A （R171H）, and two were SNP loci which were CAV1：c.246C>T （rs35242077） and CAV3：c.99C>T （rs1008642） and had significant difference （P<0.05） in allele and genotype frequencies between SUD and control groups. Forementioned variation sites were not found in CAD group. CONCLUSIONS The variants of CAV1 and CAV3 may be correlated with a part of SUD group.
Caveolins/genetics* ; Coronary Artery Disease ; Death, Sudden/etiology* ; Exons ; Genotype ; Humans ; Male ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide

BACKGROUNDAntiplatelet therapy (APT) was prevalently being used in the prevention of vascular disease, but the influence of prior APT on the prognosis of patients with intracerebral hemorrhage (ICH) remains controversial. This meta-analysis was to explore the effects of prior APT on the prognosis of patients with primary ICH.

METHODSPubMed and Embase were searched to identify the eligible studies. The studies comparing the mortality of ICH patients with or without prior APT were included. The quality of these studies was evaluated by the Newcastle-Ottawa quality assessment scale. The adjusted or unadjusted odds ratio (OR) for mortality between ICH patients with and without prior APT were pooled with 95% confidence interval (95% CI) as the effect of this meta-analysis.

RESULTSTwenty-two studies fulfilled the inclusion criteria and exhibited high qualities. The pooled OR was 1.37 (95% CI: 1.13-1.66, P = 0.001) for univariate analysis and 1.41 (95% CI: 1.05-1.90, P = 0.024) for multivariate analysis. The meta-regression indicated that for each 1-day increase in the time of assessment, the adjusted OR for the mortality of APT patients decreased by 0.0049 (95% CI: 0.0006-0.0091, P = 0.026) as compared to non-APT patients.

CONCLUSIONPrior APT was associated with high mortality in patients with ICH that might be attributed primarily to its strong effect on early time.