This article aims to compare and analyze the biomechanical differences between wing-shaped titanium plates and traditional titanium plates in fixing acetabular anterior column and posterior hemi-transverse (ACPHT) fracture under multiple working conditions using the finite element method. Firstly, four sets of internal fixation models for acetabular ACPHT fractures were established, and the hip joint stress under standing, sitting, forward extension, and abduction conditions was calculated through analysis software. Then, the stress of screws and titanium plates, as well as the stress and displacement of the fracture end face, were analyzed. Research has found that when using wing-shaped titanium plates to fix acetabular ACPHT fractures, the peak stress of screws decreases under all working conditions, while the peak stress of wing-shaped titanium plates decreases under standing and sitting conditions and increases under forward and outward extension conditions. The relative displacement and mean stress of the fracture end face decrease under all working conditions, but the values are higher under forward and outward extension conditions. Wing-shaped titanium plates can reduce the probability of screw fatigue failure when fixing acetabular ACPHT fractures and can bear greater loads under forward and outward extension conditions, improving the mechanical stability of the pelvis. Moreover, the stress on the fracture end surface is more conducive to stimulating fracture healing and promoting bone tissue growth. However, premature forward and outward extension rehabilitation exercises should not be performed.
Titanium ; Bone Plates ; Humans ; Acetabulum/surgery* ; Fracture Fixation, Internal/methods* ; Biomechanical Phenomena ; Finite Element Analysis ; Bone Screws ; Fractures, Bone/surgery* ; Stress, Mechanical ; Working Conditions

Objective To investigate the occupational health status of 450 radiation workers in a steel mill when they resigned, and to provide references and suggestions for the occupational health monitoring of the enterprise employees and for the workers’ proper arrangement after their resignations. Methods Occupational health examinations were performedon 450 steel workers who were about to resign in accordance with the applicable laws and regulations. And the examination results were statistically analyzed. Results Among the 450 radiation workers, 82% had abnormal examination results which included chromosome aberration in peripheral blood lymphocytes (4.89%), lens opacity (44.44%), pinguecula (25.33%), hypertension (28.22%), thyroid dysfunction (9.59%), and abnormal liver ultrasound findings (30.89%). Compared with the normal population, these steel workers had a significantly higher chromosome aberration rate in peripheral blood lymphocytes and a significantly higher incidence rate of ocular disorders. Conclusion It is important to effectively manage the occupational health of radiation employees in steel mills, and to regularly provide training on occupational health protection. To avoid radiation damage, workers should pay close attention to radiation protection at work, especially eye protection, to avoid eye disorders.

Objective:To explore the value of serum activin A (ACT-A) level in early identification of moderate and severe acute pancreatitis (AP).Methods:A prospective case control study was conducted. A total of 120 patients with AP admitted to department of hepatobiliary surgery of Affiliated Nanhua Hospital of Hengyang Medical College of University of South China between October 2020 and April 2022 were recruited. According to the revised Atlanta classification, all patients were classified into mild AP group and moderate-to-severe AP group. The blood samples within 24 hours of onset were drawn, and the serum ACT-A and C-reactive protein (CRP) levels were detected by enzyme-linked immunosorbent assay (ELISA). The Ranson score and the modified CT severity index (MCTSI) were performed. Pearson correlation method was used to analyze the correlation of various parameters. The receiver operator characteristic curve (ROC curve) was plotted to analyze the predictive value of ACT-A and CRP for moderate-to-severe AP.Results:A total of 120 patients with AP were enrolled, including 83 patients with mild AP and 37 patients with moderate-to-severe AP. Serum ACT-A and CRP levels within 24 hours of onset in the moderate-to-severe AP group were significantly higher than those in the mild AP group [ACT-A (ng/L): 140.4±37.7 vs. 53.9±30.5, lg CRP: 1.42±0.91 vs. 0.77±0.70, both P < 0.01], and the Ranson score and MCTSI score were also significantly higher than those in the mild AP group (Ranson score: 5.3±1.3 vs. 1.8±1.6, MCTSI score: 5.5±1.0 vs. 2.7±1.2, both P < 0.01). Correlation analysis showed that the serum ACT-A level was positively correlated with serum CRP level, Ranson score and MCTSI score ( R2 value was 0.272, 0.841, 0.616, respectively, all P < 0.05). ROC curve analysis showed that the serum ACT-A, CRP and Ranson score had predictive value for moderate-to-severe AP. The area under the ROC curve (AUC) was 0.948 [95% confidence interval (95% CI) was 0.909-0.986], 0.711 (95% CI was 0.606-0.815), 0.946 (95% CI was 0.910-0.982), respectively. When serum ACT-A > 112.6 ng/L, the sensitivity and specificity of predicting moderate-to-severe AP were 78.38% and 96.39%, respectively, which was better than serum CRP with sensitivity and specificity of 72.92% and 66.27%, respectively, and the specificity was better than Ranson score (71.08%). Conclusion:ACT-A can be detected in the early stage of AP, and it is positively correlated with the disease severity, which can early identify moderate-to-severe AP.

Objective:To investigate the clinicopathological features, differential diagnosis and prognosis of Merkel cell carcinoma (MCC).Methods:The clinical and pathological data of 10 patients with MCC were collected at the 940th Hospital of PLA. The histological characteristics were examined. Immunohistochemical EnVision method was used to detect thyroid transcription factor-1 (TTF1), broad-spectrum cytokeratin (CKpan), CK20, S-100, Ki-67, CD56, chromogranin A, synaptophysin and other markers in the 10 cases.Results:Intradermal MCC of the skin showed a nested, cord-like, cribriform distribution, polygonal cells, uniform size, and lack of cytoplasm. Tumor cell nuclei were large and round, with clear nuclear membranes, fine and scattered chromatin, absence of nucleoli, and mitotic figures of 10 per 50 high power fields. Among them, one patient had sarcoma and squamous cell carcinoma in situ, one patient had squamous cell carcinoma in situ, and one patient had unique cell morphology. Immunohistochemical staining showed that all cancer cells expressed CKpan, synaptophysin and CD56. There were seven cases with perinuclear dot-like positivity of CK20. Six MCCs expressed chromogranin A to varying degrees, while 2 MCCs were weakly positive for p63. The nuclear positive index in the Ki-67 hotspot area was 60%.Conclusion:The histology of MCC varies. Rendering a correct diagnosis of MCC requires adequate sampling, close correlation with clinical history and rational use of immunohistochemical staining. The treatment requires standardized surgery, postoperative radiotherapy and multimodal chemotherapy. Immunotherapy may replace the traditional treatment in the future.

Objective:To repair the secondary mandibular angle caused by madibular osteotomy by using digital technology and to make quantitative comparative evaluation.Methods:Thirty-nine patients with secondary mandibular angle with unsmooth mandibular margin or bilateral asymmetry after mandibular osteotomy in Southern Theater General Hospital from 1996 to 2017 were included. The three-dimensional model of skull was established by CT skull scan and Mimics 13.0 software. The computer aided design was used to carry out the secondary surgical repair according to the design line, and the mandibular angle was quantitatively measured and evaluated before and after the revision operation. The mandibular angles before, after design and after restoration were measured on the reconstructed images, and the bilateral symmetry and the consistency between the design result and the final result were compared by Paired- t sample test. P< 0.05 indicates statistical difference. Results:All the 39 patients completed the operation successfully, and 1 case developed hematoma 15 days after operation, which was drained and bandaged by oral dressing. Two weeks after operation, the hematoma was resolved. No infection, nerve injury and accidental fracture of mental process were found in all patients. During the 6-month follow-up, the mandibular angle of 39 patients improved from 118.12°±18.08° on the left side and 114.60°±16.01° on the right side to 121.28°±6.96° on the left side and 121.32°±5.88° on the right side. There was significant difference between the left and right sides before operation ( t=1.744, P=0.045), but there was no significant difference between the two sides about 6 months after operation( t=-0.074, P=0.529). The angle of mandibular angle after design was compared with the actual outcomes of patients 6 months after operation and there was no significant difference( t=-0.527, P=0.601). All the patients were satisfied with the improvement of the secondary mandibular angle and facial shape. Conclusions:The application of digital technique to repair the secondary mandibular angle after mandibular osteotomy not only avoids the injury of inferior alveolar neurovascular bundle and mental nerve, but also effectively improves the facial shape of the patients.

Objective:To repair the secondary mandibular angle caused by madibular osteotomy by using digital technology and to make quantitative comparative evaluation.Methods:Thirty-nine patients with secondary mandibular angle with unsmooth mandibular margin or bilateral asymmetry after mandibular osteotomy in Southern Theater General Hospital from 1996 to 2017 were included. The three-dimensional model of skull was established by CT skull scan and Mimics 13.0 software. The computer aided design was used to carry out the secondary surgical repair according to the design line, and the mandibular angle was quantitatively measured and evaluated before and after the revision operation. The mandibular angles before, after design and after restoration were measured on the reconstructed images, and the bilateral symmetry and the consistency between the design result and the final result were compared by Paired- t sample test. P< 0.05 indicates statistical difference. Results:All the 39 patients completed the operation successfully, and 1 case developed hematoma 15 days after operation, which was drained and bandaged by oral dressing. Two weeks after operation, the hematoma was resolved. No infection, nerve injury and accidental fracture of mental process were found in all patients. During the 6-month follow-up, the mandibular angle of 39 patients improved from 118.12°±18.08° on the left side and 114.60°±16.01° on the right side to 121.28°±6.96° on the left side and 121.32°±5.88° on the right side. There was significant difference between the left and right sides before operation ( t=1.744, P=0.045), but there was no significant difference between the two sides about 6 months after operation( t=-0.074, P=0.529). The angle of mandibular angle after design was compared with the actual outcomes of patients 6 months after operation and there was no significant difference( t=-0.527, P=0.601). All the patients were satisfied with the improvement of the secondary mandibular angle and facial shape. Conclusions:The application of digital technique to repair the secondary mandibular angle after mandibular osteotomy not only avoids the injury of inferior alveolar neurovascular bundle and mental nerve, but also effectively improves the facial shape of the patients.

Objective: To study the characteristics of maxillofacial contour data of male young adult group and to compare the differences between data acquired by structured light three-dimensional scanning and CT. Methods: From November 2017 to December 2017, 120 healthy male volunteers from the General Hospital of Southern Theatre Command aged 20 to 30 years, weighed 55-85 kg, and with the height between 160-185 cm were selected. Three groups were carried out according to the concentrative trend of BMI: 17≤BMI<22(group A), 22≤BMI<24(group B), 24≤BMI<29(group C). Structured light scanning: Each volunteer underwent facial scanning and measurement by 3D medical simulation system and 3D precision digital shaping software in the system respectively. CT scanning: CT was also used for whole skull scanning and the harvested 3D data was calculated and measured with Mimics 13.0 and Geomagic Studio 2013 software. Three groups of measurements were statistically compared between groups using Paired-t sample test, One-way ANOVA or Wilcoxon rank sum test. P<0.05 indicates statistical difference. Results: The result of structured light three-dimensional scanning data showed that the horizontal circumference of supraauricular base point (point A), tragus point (point B), earlobe point (point C) and midpoint of lip plane (point D) in group A were (276.70±11.71) mm, (286.06±7.69) mm, (256.53±11.01) mm, (244.89±11.85) mm. The values in group B were (289.22±8.91) mm, (301.57 ±3.61) mm, (270.68±11.85) mm and (257.02±11.76) mm. The values in group C were (297.53±5.70) mm, (314.12±4.73) mm, (278.29±9.04) mm and (260.21±17.33) mm. The results of CT three-dimensional reconstruction model: the horizontal circumference of superior ear base point, tragus point, ear lobe point and lip plane midpoint in group A were (274.55±9.98) mm, (283.33±7.35) mm, (260.32±12.64) mm, (241.97±11.94) mm. The values in group B were (286.40±7.29) mm, (300.28±2.73) mm, (274.89±7.91) mm and (253.84±12.04) mm. The values in group C were (293.27±8.18) mm, (310.38±8.43) mm, (283.41±10.94) mm and (254.67±13.71) mm. There was no significant difference between the two collection method (P>0.05). The statistical result of structured light three-dimensional scanning image data showed that there were significant differences between group A and group B, group A and group C, group B and group C(t=-5.798 6, -8.109 0, -4.044 3; P=0.000 0, 0.000 0, 0.000 1). By the circumference of horizontal plane at point B, there were significant differences between group A and group B, group A and group C, group B and group C(t=-12.190 0, -16.206 7, -12.054 2; P=0.000 0, 0.000 0, 0.000 0). There were significant differences in horizontal plane circumference between group A and group B, group A and group C, group B and group C(t=-6.078 8, -8.346 5, -2.686 5; P=0.000 0, 0.000 0, 0.009 2). Through the horizontal plane circumference of point C, there were significant differences between group A and group B, group A and group C, group B and group C. Through the horizontal plane circumference of point D, there were significant differences between group A and group B, group A and group C(t=-5.025 1, -4.495 4; P=0.000 0, 0.000 0). The difference between group B and group C was not statistically significant (t=-0.886 6, P=0.378 6). The statistical result of CT scanning reconstruction model data showed that there were significant differences in horizontal plane circumference between group A and group B, group A and group C, group B and group C(t=-6.520 5, -7.924 5, -3.495 7; P=0.000 0, 0.000 0, 0.000 9). According to the horizontal plane circumference of point B, there were significant differences between group A and group B, group A and group C, group B and group C. There were significant differences in horizontal plane circumference between group A and group B, group A and group C, group B and group C. By the circumference of horizontal plane at point C, there were significant differences between group A and group B, group A and group C, group B and group C(t=-6.596 1, -7.622 4, -3.637 7; P=0.000 0, 0.000 0, 0.000 6). According to the horizontal plane circumference of point D, there were significant differences between group A and group B, group A and group C (t=-4.846 0, -4.085 3; P=0.000 0, 0.000 1). The difference between group B and group C was not statistically significant (t=-0.254 2; P=0.800 1). Conclusions The three-dimensional data of the maxillofacial region of male young adults has a correlation with the BMI. Structured light three-dimensional scanning is a more accurate and convenient way to collect three-dimensional data of maxillofacial contour than CT scanning, which is helpful to improve the efficiency of clinical and scientific research.

The anterior chest is an excellent donor site for cervicofacial reconstruction. Studies of chest flaps began as early as 1988 in xijing Hspital. We created a new flap called the subclavicular flap, which was pedicled by the thoracic branch of supraclavicular artery. This flap shares the similar vascular territory of the deltopectoral flap and is mainly used for reconstruction of cervicofacial wounds. The supraclavicular flap has the same vessel origin of supraclavicular flap but is pedicled by the different branch, the deltoid branch. Its vascular territory locates on the shoulder region. Therefore, many differences and relations exist between the two flaps and there are also some disputes. To enhance the understanding of the two flaps, presenting a summary on the two flaps, especially for their relations and differences.

Objective: To investigate the feasibility of one-stage thinning of latissimus dorsi muscle, rectus abdominis muscle and gracilis flap in reconstruction of the hand and foot defects. Methods: From June 2009 to April 2015, 24 free muscle flaps were thinned during transfer operation by removing their superficial muscle layers on the basis of their vessel pedicles running in the deep surface of flaps. The surface of the muscle flaps were covered by split-thickness skin grafts. There were 16 latissimus dorsi muscle flaps, 4 gracilis flaps and 4 rectus abdominis muscle flaps. Flap size ranged from 6 cm×4 cm to 20 cm×12 cm. Thinned muscle flaps were used to resurface 7 hand defects and 17 foot defects. Results: All muscle flaps survived the thinning procedures without any circulation problems except for one case which suffered total flap necrosis due to venous thrombosis. Skins grafts on muscle flaps also took well. One patient experienced partial skin loss. Two patients underwent secondary debridement and thinning procedure for infection and bulkiness. During the 0.3-20 months follow-up, the contour of thinned muscle flaps matched well with the recipient areas. Reconstructed feet are able to wear regular shoes. Conclusions Intraoperative immediate thinning of free muscle flaps can be safely accomplished during the primary reconstruction procedure. This procedure prevents the limitations of muscle flap bulkiness and may provide an alternative for surface coverage.

Objective The absorbable haemostatic membrane was used to stop bleeding during posterior spinal surgery so as to investigate the therapeutic effect and the security of the absorbable haemostatic membrane. Methods Ninety-four patients were enrolled into the experimental group and the control group. In the experimental group , the decompression wound is handled by using the regular absorbable haemostatic membrane to stop bleeding. In the control group , the conventional surgical methods , such as coagulation , brain cotton and other methods were used to stop bleeding. After the operations , patients in two groups were given indwelling vacuum drainage tube. The post operation vacuum pipe drainage , the drainage tube removing time , the incidence of postoperative complications after removing drainage tubes , the reoperation number , vital signs after 24 hour (temperature, respiration, pulse, blood pressure), and laboratory tests (blood count, coagulation function parameters) were determined and compared between two groups. Results Both the vacuum drainage at 24 hours post operation and the total vacuum drainage post operation were significantly reduced in the experimental group(P < 0.05, respectively). No significant differences in the coagulation function parameters were found between both two groups. Conclusion The absorbable haemostatic membrane may be applicable for spinal surgery.