OBJECTIVETo compare the stability of sacroiliac screws fixation for the treatment of bilateral vertical sacral fractures to provide reference for clinic application.

METHODSA finite element model of Tile C pelvic ring injury (bilateral type Denis II fracture of sacrum) was produced. The bilateral sacral fractures were fixed with sacroiliac screws in 4 types of models respectively: two bidirectional sacroiliac screws fixation in the S₁ segment, two bidirectional sacroiliac screws fixation in the S₂ segment, one sacroiliac screw fixation in the S₁ segment and one sacroiliac screw fixation in the S₂ segment, two bidirectional sacroiliac screws fixation in S₁ and S₂ segments respectively. By the ABAQUS 6.9.1 software, in the case of standing on both feet, 600 N vertical load was imitated to be imposed to the superior surface of the sacrum and downward translation and backward angle displacement of the middle part of the sacral superior surface and everted angle displacement of the top of iliac bones were extracted for analysis. The stability of sacroiliac screws fixation was compared according to the principle of the better stability the smaller displacement.

RESULTSThe stability of 2 bidirectional sacroiliac screws fixation in S₁ and S₂ segments respectively was markedly superior to that of 2 bidirectional sacroiliac screws fixation in S₁ or S₂ segment and was also markedly superior to that of one sacroiliac screw fixation in S₁ segment and one sacroiliac screw fixation in S₂ segment. The vertical and everted stability (the downward translation: 0.531 mm; the everted angle displacement: 0.156° (left side), 0.163° (right side)) of sacroiliac screws fixation in two bidirectional sacroiliac screws fixation in the S₂ segment was superior to that of two bidirectional sacroiliac screws fixation in the S₁ segment (the downward translation: 0.673 mm; the everted angle displacement: 0.200° (left side), 0.232° (right side)). The rotational stability of two bidirectional sacroiliac screws fixation in the S₁ segment (the backward angle displacement: 0.269°) was superior to that of two bidirectional sacroiliac screws fixation in the S₂ segment (the backward angle displacement: 0.287°). Moreover, the rotational stability of one sacroiliac screw fixation in the S₁ segment and one sacroiliac screw fixation in the S₂ segment was inferior to that of two bidirectional sacroiliac screws fixation in the S₁ segment or two bidirectional sacroiliac screws fixation in the S₂ segment, and the vertical and everted stability of one sacroiliac screw fixation in the S₁ segment and one sacroiliac screw fixation in the S₂ segment was between that of two bidirectional sacroiliac screws fixation in the S₁ segment and two bidirectional sacroiliac screws fixation in the S₂ segment.

CONCLUSIONSTwo bidirectional sacroiliac screws fixation in S₁ and S₂ segments respectively is recommended to be utilized for fixing bilateral sacral fractures of Tile C pelvic ring injury as far as possible. It is suggested to choose sacral segments in which sacroiliac screws fixed according to vertical, rotational and everted stability degree of sacral fractures.

Adult ; Bone Screws ; Computer Simulation ; Female ; Finite Element Analysis ; Fracture Fixation, Internal ; methods ; Fractures, Bone ; surgery ; Humans ; Sacrum ; injuries ; surgery

Objective To study the relationship between the expression of apoptosis inducing factor (AIF) and neuronal apoptosis in rats with focal ischemia reperfusion.Methods Wistar rats were divided into sham-operated (n=6) and model (n=30) groups.Middle cerebral artery occlusion (MCAO)models were established by thread ligation.The expression of AIF in the ischemic penumbra was observed in the sham-operated and model groups 6 h and 1,2,3 and 7 d after the reperfusion; the changes of neuronal apoptosis in corresponding region were observed by TUNEL staining at the same time.Results AIF-positive cells in the ischemic penumbra were significantly increased in the model group 6 h after the ischemic reperfusion,reaching its peak level at 48 h of reperfusion (130.47±11.32 cells).Cell apoptosis occurred at each time point of ischemic reperfusion and the percentage of apoptosis cells at 48 h ofreperfusion (118.53±11.67 ceils) was the highest among all the time points.Significant differences between the 2 groups were found between each 2 time points (P<0.05).Conclusion Focal ischemia reperfusion can induce the increased expression of AIF positive cells and neuronal apoptosis.

Objective::To investigate the correlation between the characteristics and internal quality of Ophiopogonis Radix from Sichuan province through various quality evaluation, and provide reference for the formulation of grading standard of this herb. Method::For 28 batches of Ophiopogonis Radix, the characters, microscopic characteristics, thin-layer chromatography (TLC), the content of moisture, ash content, acid insoluble ash content, residues of sulfur dioxide, heavy metals, hazardous elements and paclobutrazol, water-soluble extract, contents of total saponins and three major components [ophiopogonin D (OPD), methylophiopogonanone A (MPOA) and methylophiopogonanone B (MPOB)] were determined.The relationships between various indicators and the grade of Ophiopogonis Radix were analyzed. Result::Ophiopogonis Radix exhibited specific properties in characters, microscopic characteristics and TLC.The contents of impurity, moisture, total ash, acid-insoluble ash and water-soluble extract existed differences in four grades of Ophiopogonis Radix from Sichuan province.For grade Ⅰ, grain number was 80-120 grains per 50 g, the moisture content was 11.1%-14.9%, total ash content was 1.6%-2.1%, acid-insoluble ash content was 0.03%-0.14%, water-soluble extract content was 77.0%-86.5%.For grade Ⅱ, grain number was 120-160 grains per 50 g, the moisture content was 13.1%-14.2%, total ash content was 1.3%-2.2%, acid-insoluble ash content was 0.06%-0.22%, water-soluble extract content was 75.9%-83.3%.For grade Ⅲ, grain number was 160-300 grains per 50 g, the impurity was 0.2%-8.4%, the moisture content was 12.6%-14.0%, total ash content was 1.2%-1.5%, acid-insoluble ash content was 0.06%-0.22%, water-soluble extract content was 74.0%-86.5%.For grade Ⅳ, grain number was 80-300 grains per 50 g, impurity was 1.2%-22.6%, the moisture content was 13.0%-15.4%, the total ash content was 1.4%-2.0%, acid-insoluble ash content was 0.03%-0.15%, water-soluble extract content was 79.8%-85.2%. Conclusion::It is reasonable and feasible to classify the grade of Ophiopogonis Radix from Sichuan province according to the appearance characteristics such as the grain number per 50 g and internal indexes such as impurity and water-soluble extract, which can be used as a reference for grading standards of Ophiopogonis Radix from Sichuan province.