[Clinical characteristics of posterior malleolus fracture in adults].

Objective: To explore the latest clinical characteristics and development trends of posterior malleolus fracture. Methods: Clinical information of inpatients with posterior malleolus fracture in Shanghai Tongji Hospital and Karamay Central Hospital from January 2014 to December 2022 were reviewed and collected. The imaging data of patients were acquired using the Picture Archiving and Communication Systems. A statistical analysis was performed as to gender, current age, year of admission, injury mechanism, fracture type, and posterior malleolus fracture classification. Moreover, a comparative analysis was conducted on the injury mechanisms and morphological differences of posterior malleolus fracture at different periods, regions, and age groups. Results: A total of 472 patients (210 patients from Shanghai Tongji Hospital and 262 patients from Karamay Central Hospital) with posterior malleolus fracture with a mean age of (48.7±15.6) years were included in this study. The peak of posterior malleolus fracture occurs in the age group of 50-59 years. The injury mechanisms mainly involve low-energy fall and sprain (411 cases, 87.1%), followed by traffic accidents (52 cases, 11.0%), and fall injury from height (9 cases, 1.9%). The number of cases according to different fracture types showed the following descending order: trimalleolar fracture-supination extorsion (335 cases, 71.0%), bimalleolar fracture (60 cases, 12.7%), trimalleolar fracture-pronation extorsion (43 cases, 9.1%), posterior malleolus+tibial shaft fracture (19 cases, 4.0%), simple posterior malleolus fracture (15 cases, 3.2%). The numbers of cases corresponding to the Haraguchi Ⅰ, Ⅱ and Ⅲ type of posterior malleolus fractures was 369 (78.2%), 49 (10.4%), and 54 (11.4%), respectively. The Tongji ⅡA type represented the highest number of cases (249 cases, 52.8%), followed by the ⅡB type (120 cases, 25.4%), Ⅰ type (54 cases, 11.4%), ⅢB type (36 cases, 7.6%), and ⅢA type (13 cases, 2.8%). However, no obvious statistical difference was observed in the injury mechanism, Haraguchi classification, and Tongji classification of posterior malleolus fractures among different years and regions from the year of 2014 to 2022 (all P>0.05). Conclusions: The injury mechanism of posterior malleolus fracture mainly involves low-energy fall and sprain cases. The trimalleolar fracture-supination extorsion, Haraguchi Ⅰ type and Tongji ⅡA type of posterior malleolus fracture are predilection fracture types, and all present an obvious incidence peak in the age group of 50-59 years. There has been no significant change in the development trend of clinical characteristics of posterior malleolus fractures in recent years.

[Analysis of spontaneous nystagmus and the frequency characteristics of affected semicircular canals in patients with vestibular neuritis].

Objective: To investigate the spontaneous nystagmus (SN) and the frequency characteristics of affected semicircular canals in patients with vestibular neuritis (VN). Methods: This is a cross-sectional study. A total of 61 patients with VN admitted to the Department of Neurology of Shanxi Bethune Hospital from June 2020 to October 2021, 39 were male and 22 were female, with a mean age of (46±13) years old and male to female ratio of 1.77∶1. According to SN characteristics, 61 patients were divided into non-nystagmus group(nSN), horizontal nystagmus group(hSN) and horizontal-torsional nystagmus group (htSN). Clinical data were collected, and SN, unilateral weakness (UW), directional preponderance (DP), and video head impulse test (vHIT) gain were used as observation indicators. Statistical analysis by SPSS23.0 software. Normal distributed quantitative data (age, semicircular canal gain, SN intensity) were expressed by x¯±s, non-normal distributed quantitative data (disease course, UW, DP) were expressed by M(Q1,Q3), qualitative data were expressed by rate and composition ratio, difference analysis by one-way ANOVA, rank sum test, Chi-square test or Fisher's exact probability method, considered by P value<0.05. Results: (1)The disease course of nSN, hSN and htSN was 7.0 (4.0, 12.5), 6.0 (3.5, 11.5), and 3.0 (2.0, 6.5) days respectively, and there were statistical differences (χ2=7.31,P=0.026).(2)The horizontal nystagmus intensity of htSN was (16.8±8.6)°/s, which was significantly higher than that of (9.8±4.7)°/s in hSN (t=3.71, P<0.001). There was no significant difference in the positive rate of UW between the three groups (P=0.690), and there was a significant difference in the positive rate of DP in the three groups (χ2=12.23, P=0.002). The horizontal nystagmor intensity in the htSN was positively correlated with the vertical nystagmus intensity (r=0.59, P=0.001).(3)The gain of the affected horizontal canal of the three groups was statistically different (F=8.28, P=0.001), and the gain of the horizontal canal of hSN and htSN was significantly lower than that of nSN (t=2.74, P=0.008; t=4.05, P<0.001); The gain of the affected anterior canal in the three groups was statistically different (F=5.32, P=0.008). The gain of the anterior canal in both nSN and hSN was significantly higher than that in htSN (t=3.09, P=0.003; t=2.15, P=0.036). The horizontal canal gain of htSN is positively correlated with the anterior canal gain (r=0.74, P<0.001).(4)The affected semicircular canals in the two groups with no-vertical-component nystagmus (nSN and hSN) and the htSN were counted. The composition ratio of the affected semicircular canals in the two groups was different (χ2=8.34, P=0.015). Conclusion: The occurrence of SN in patients with VN is related to many factors, such as the disease course, low and high frequencies, and the severity of the condition in the affected semicircular canal.

[Distribution and reference intervals of daytime intraocular pressure in the eye health screening population of Handan].

Objective: To describe the distribution and establish reference intervals (RI) of daytime intraocular pressure (IOP) in the eye health screening population of Handan. Methods: This cross-sectional study included subjects who participated in eye health screening at the Physical Examination Center of Handan First Hospital from May 2021 to June 2022. A complete general and ocular examination was performed, including measurements of visual acuity and IOP (using Goldmann tonometry), slit lamp microscopy, fundus photography, and anterior and posterior segment optical coherence tomography. Subjects with factors that could cause significant changes in IOP or affect the accuracy of IOP measurement, or with an inability to measure IOP were excluded. Simple random sampling was used to select participants, who were grouped by gender and age (18 to <30, 30 to <40, 40 to <50, 50 to <60, 60 to <70, and ≥70 years). Central corneal thickness and IOP at 8 to 11 o'clock in one eye of each participant were recorded. The independent sample t test and ANOVA were used for statistical analysis, and the RI of IOP values was calculated by x¯±1.96s. Results: A total of 9 310 subjects had their IOP measured, and 3 491 participants (3 491 eyes) were randomly selected from 7 886 healthy subjects. The age of the participants was (47.74±14.47) years old, ranging from 18 to 90 years old. There were 1 694 males and 1 797 females. The central corneal thickness of all participants was (525.56±49.39) µm. The daytime IOP of all participants was (15.40±2.54) mmHg (1 mmHg=0.133 kPa), and the RI was 10.42 to 20.39 mmHg. The IOP was (15.49±2.58) mmHg for males and (15.29±2.49) mmHg for females, and the gender difference was statistically significant (P<0.05). The RI of daytime IOP values was 10.43 to 20.54 mmHg for males and 10.41 to 20.18 mmHg for females. There were significant differences in daytime IOP [(15.13±2.58), (15.33±2.53), (15.49±2.50), (15.53±2.55), (15.39±2.62), and (15.28±2.52) mmHg] among 6 age groups (P<0.05). Conclusions: The distribution of daytime IOP in different gender and age groups in the eye health screening population of Handan and the RIs derived from the distribution were roughly the same as the international normal IOP RI (10 to 21 mmHg). It is recommended to refer to the RI of daytime IOP values of different genders and ages for clinical decision.

Parameterized Analysis of Craniocerebral Injury Caused by Fist.

ABSTRACT: Objective Based on the theory of biomechanics, the finite element method was used to study the injury characteristics of different parts of brain hit by fist with different force and to predict the risk of craniocerebral injury, in order to provide reference for actual medical protection and forensic identification. Methods The finite element model of fist was constructed by using DICOM data modeling method and related software, and the effective mass and speed of fist were used to represent the kinetic energy of fist, and combined with human finite element model THUMS 4.02, the characteristics of craniocerebral injury caused by frontal and lateral blows were parametrically simulated. Results The probability of direct death from a blow to the head was low, but as fist power increased, so did the risk of craniocerebral injury. The characteristics of craniocerebral injury were also significantly different with the different fist hitting head locations. When the frontal area was attacked, the maximum equivalent stress of skull was 122.40 MPa, while that of brain tissue was 4.31 kPa. When the temporal area was attacked, the maximum equivalent stress of skull was 71.53 MPa, while that of brain tissue was 7.09 kPa. Conclusion The characteristics and risks of skull fracture and brain tissue injury are different when different parts of the brain are hit by fist. When the frontal area is hit, the risk of skull fracture is significantly higher than when the temporal area is hit. The risk of brain tissue injury is the opposite. The position with the highest probability of skull fracture is generally the place where the skull is directly impacted, and with the conduction of stress waves, it will spread to other parts of the skull, while the position with the highest risk of brain tissue injury is not the place where the brain is directly impacted.

[The effects and mechanism of baicalin in a mouse acute hypertensive glaucoma model].

Objective: To explore the potential neuroprotection effects and associated mechanism of baicalin in a rodent acute hypertensive glaucoma model and oxygen-glucose deprivation/reperfusion (OGD/R) induced retinal ganglion cell (RGC) injury. Methods: Experiment research. A rapid and substantial elevation of intraocular pressure was performed to establish an acute hypertensive glaucoma model, and retinal thickness was assessed at 1, 3, 5, and 7 days. The mice were then randomly divided into three groups: normal control group, hypertension group, and baicalin (50 mg/kg) for hypertension group. The effects of baicalin on the RGCs were evaluated by retrograde transporting of Fluoro-Gold. The mRNA levels of tumor necrosis factor-α, interleukine-1ß (IL-1ß), and inducible nitric oxide synthase were detected by real-time PCR, and the protein levels were measured by Western blot in the retina tissue of acute hypertensive glaucoma model. Purified primary RGC survival under OGD/R stress was measured by flow cytometry, which was also performed to measure the survival rate of RGCs pretreated by different doses of baicalin (2.5 µmol/L, 5.0 µmol/L, and 10.0 µmol/L). The effects of baicalin on primary RGCs co-cultured with mouse microglia cell line BV2 were evaluated by flow cytometry. The cytokine IL-1ß in the culture supernatant was measured by immunochemical analyses. Statistical analysis was performed using analysis of variance. Results: Retinal tissue injuries and RGC loss were observed both in vivo and in vitro. Retinal thickness was decreased to 87.32%±0.94% at 3 days (t=6.73, P<0.01), 74.86%±2.43% at 5 days (t=13.40, P<0.01), and 63.53%±2.15% at 7 days (t=19.46, P<0.01). Treatment of 50 mg/kg baicalin significantly promoted the RGC survival from 61.32%±5.94% to 89.93%±10.08% (t=4.84, P<0.01). Baicalin alleviated the retinal damages by suppressing the expression of inflammatory cytokines as revealed by Western blot and real-time PCR. In vitro the RGC survival under OGD/R stress was increased from 51.53%±1.36% to 69.37%±7.09% and 66.23%±4.25% with 5.0, 10.0 µmol/L baicalin administration (t=5.50, 4.53; both P<0.01). BV2 under OGD/R stress did extra damage to RGCs, and baicalin could reverse the damages and increase the survival from 69.37%±7.09% to 73.00%±5.20% (t=2.82, P=0.048) by reducing the release of IL-1ß [(39.97±8.76) pg/ml vs. (61.33±5.78) pg/ml, t=4.19, P=0.010]. Conclusion: Baicalin could alleviate retina tissue injury directly and promote the survival of RGCs by downregulating the expression of inflammatory cytokines and protecting RGCs from ischemia reperfusion injury. (Chin J Ophthalmol, 2020, 56: 376-382).

[Analysis of Influencing Factors of Single Camera Photogrammetry in Forensic Three-Dimensional Reconstruction].

ABSTRACT: Objective To evaluate the influence of factors such as the selection of equipment, focal length and the selection of reconstruction quality in the reconstruction software on the reconstruction results of single camera photogrammetry and provide reference for the forensic application of single camera photogrammetry. Methods The 19 skulls were measured by traditional measurement method and single camera photogrammetry. The differences between the two measurement methods and within the group with same equipment but different focal length were analyzed. One skull and one corpse were selected as the research objects. According to the reconstruction quality selection conditions in the photogrammetric software, the experimental group was divided into five grades. The model reconstructed by optical scanner was defined as reference model, while the model reconstructed by single camera photogrammetry was defined as test model. The test model was aligned with the reference model, 3D deviation analysis was carried out and the mean error and root mean square （RMS） values were calculated. Results The differences between EOS 7D zoom group and traditional measurement, and within the group with same equipment had statistical significance （P<0.05）. The mean error value and minimum RMS value of the skull reconstructed by single camera photogrammetry and the three-dimensional model of the corpse existed in the medium quality group, and the trend was basically the same. Conclusion The equipment and focal length has no obvious influence on the results of single camera photogrammetry. Lower reconstruction quality can easily cause distortion, while higher reconstruction quality can easily generate noise, so medium quality is preferred.

Exploring of the Mechanism of Rib Fracture Caused by Landing on Different Parts of the Trunk after Falls from Height Using Finite Element Method.

ABSTRACT: Objective To study the mechanism of rib fracture caused by landing on different parts of the trunk using finite element method, and to provide some new techniques and new ideas for the reconstruction of the whole process of falls from height. Methods The finite element method was used to study the rib fracture of human security model THUMS4.0 caused by landing on different parts of the trunk. Then the model was compared with actual cases and the mechanism of rib fracture caused by falls from height was analyzed from a biomechanical point of view. Results There were some differences in the stress and strain distribution as well as the rib fracture sites when different parts touched the ground. Ribs on both sides of the body were fractured when the front of the trunk touched the ground, and the fractures were mainly located in the junction of the ribs and costal cartilage and the midaxillary line area. When the right anterior part of the trunk touched the ground, rib fracture occurred first on the side that touched the ground, and rib fractures were mainly located in the area from the right midaxillary line to the posterior axillary line, and junction of ribs on both sides and costal cartilage. When the back of the trunk touched the ground, the fracture sites were mainly located on the back of the ribs on both sides. When the right posterior part of the trunk touched the ground, multiple rib fractures were likely to occur in the parts that touched the ground. The plastic strains were mainly concentrated at the fracture sites, while the von Mises stresses were not only concentrated at the fracture sites, but also at other sites. Conclusion There are some differences in rib fracture location sites and injury mechanisms when different parts of the trunk touch the ground.

Evaluation of 3D Measuring Methods for Body Surface Damage and Scars.

ABSTRACT: Objective To assess the accuracy and reliability of the two 3D measuring methods, structured-light scanning and single-camera photogrammetry in forensic body surface damage and scar measurement. Methods The measuring results of 86 injuries by the ruler method, structured-light scanning and single-camera photogrammetry were compared and evaluated. The area measuring results of 13 simulated scars by the structured-light scanning, single-camera photogrammetry, Photoshop lasso pixel method and PDF reading software were compared and evaluated. The time consumed was recorded. The known specification information of the stickers was used as the standard value to compare the measuring accuracy of the ruler method, structural-light scanning and single-camera photogrammetry, and to calculate the root mean square error （RMSE）. The consistency evaluation of intraclass correlation coefficient （ICC） for the repeatability of 3 measuring results obtained by different operators and the same operator. Results The differences in results of the two 3D measuring methods and the ruler method had no statistical significance; the differences between measuring results made by the structured-light scanning, single-camera photogrammetry and PDF reading software and that of the Photoshop lasso pixel method had no statistical significance. The post-processing of the single-camera photogrammetry consumed more time than that of other methods. When the long-distance group （10-40 cm） was measured, the results obtained by the ruler method were shorter than the standard value. The RMSE value results were structured-light scanning < single-camera photogrammetry < ruler method. The ICC value intragroup and intergroup were greater than 0.99. Conclusion Both structured-light scanning and single-camera photogrammetry can be applied in recording and measuring forensic body surface damage. The former has better performance in measurement accuracy and stability, while the latter has better color performance but longer post-processing time.

[Research Status of Postmortem MSCT Angiography in Forensic Science].

ABSTRACT: Virtual autopsy is a new technique for investigating the morphological changes of cadaveric tissues and organs by medical imaging technology. It has been widely used in the identification of causes of death. Multislice spiral computed tomography （MSCT） has become a routine inspection method in some identification institutions, although it cannot completely replace traditional autopsy, it plays a key auxiliary or substitute role in the identification of certain abnormal causes of death. Plain MSCT scan cannot visualize cadaveric vessels, but can perform cadaveric angiography to determine vascular injury or disease. This technology has entered a rapid development period in recent years, and has made a considerable progress in contrast agent, perfusion methods and imaging methods. This article summarizes several common cadaveric MSCT angiography methods, such as systemic angiography, angiography through cardiopulmonary resuscitation, targeted angiography, and angiography by cardiac puncture, and analyzes and compares the application prospects.

[Selective tarsometatarsal arthrodesis for old Lisfranc injury].

Objective: To discuss the methods and clinical outcomes of selective tarsometatarsal (TMT) arthrodesis for old Lisfranc injury. Methods: The clinical data of 36 cases with old Lisfranc injury treated by selective arthrodesis from January 2010 to October 2016 in the Department of Orthopedics in Shanghai Sixth People's Hospital were analyzed retrospectively. There were 16 males and 20 females in this group with a mean age of (40±6) years. The information of pre-operative and post-operative X-ray, American Orthopaedics Foot and Ankle Society (AOFAS) midfoot score and pain Visual Analogue Scale (VAS) score was collected. The complications were also recorded. The pre- and post-operative data were compared with t test. Results: The 36 patients got a follow-up for at-least 2 years (averaged (4.3±1.6) years, ranged from 2 to 8 years). The post-operative AOFAS midfoot score was improved from (44±7)(28-60) to (83±7)(76-97)(t=-37.1, P<0.05), and the VAS score decreased from (6.3±2.5)(5-9) to (1.6±1.3)(0-3)(t=23.7, P<0.05). Implant breakage occurred in two patients and the symptom was relieved after the removal of implants. Conclusion: The selective TMT arthrodesis for old Lisfranc injury may relieve the symptoms, improve the function and life quality of patients by restoring the medial arch and midfoot and forefoot alignment.