Finite element analysis of PMMA bone cement reinforced screw plate fixation for osteoporotic proximal humeral fracture / 中国骨伤

OBJECTIVE@#With the help of finite element analysis, to explore the effect of proximal humeral bone cement enhanced screw plate fixation on the stability of internal fixation of osteoporotic proximal humeral fracture.@*METHODS@#The digital model of unstable proximal humeral fracture with metaphyseal bone defect was made, and the finite element models of proximal humeral fracture bone cement enhanced screw plate fixation and common screw plate fixation were established respectively. The stress of cancellous bone around the screw, the overall stiffness, the maximum stress of the plate and the maximum stress of the screw were analyzed.@*RESULTS@#The maximum stresses of cancellous bone around 6 screws at the head of proximal humeral with bone cement enhanced screw plate fixation were 1.07 MPa for No.1 nail, 0.43 MPa for No.2 nail, 1.16 MPa for No.3 nail, 0.34 MPa for No.4 nail, 1.99 MPa for No.5 nail and 1.57 MPa for No.6 nail. These with common screw plate fixation were:2.68 MPa for No.1 nail, 0.67 MPa for No.2 nail, 4.37 MPa for No.3 nail, 0.75 MPa for No.4 nail, 3.30 MPa for No.5 nail and 2.47 MPa for No.6 nail. Overall stiffness of the two models is 448 N/mm for bone cement structure and 434 N/mm for common structure. The maximum stress of plate appears in the joint hole:701MPa for bone cement structure and 42 0MPa for common structure. The maximum stress of screws appeared at the tail end of No.4 nail:284 MPa for bone cement structure and 240.8 MPa for common structure.@*CONCLUSION@#Through finite element analysis, it is proved that the proximal humerus bone cement enhanced screw plate fixation of osteoporotic proximal humeral fracture can effectively reduce the stress of cancellous bone around the screw and enhance the initial stability after fracture operation, thus preventing from penetrating out and humeral head collapsing.

Surgical treatment methods and classification of proximal clavicle fracture / 中国骨伤

OBJECTIVE@#To summarize the surgical treatment of different proximal clavicle fractures, and discuss the classification of proximal clavicle fractures.@*METHODS@#Total of 24 patients with displaced proximal clavicle fractures were treated from January 2017 to December 2020 including 16 males and 8 females, aged 28 to 66 years old. Among them, 20 cases were fresh fractures and 4 cases were old fractures. According to the Edinburgh classification, 14 cases were type 1B1 fractures and 10 cases were type 1B2 fractures. The different internal fixation methods were selected for internal fixation treatment according to different fracture types.The operation time, blood loss, preoperative and postoperative displacement difference, fracture healing time and Rockwood scoring system were recorded.@*RESULTS@#All patients were followed up for 12 to 24 months. There were no patients with infection or loss of reduction after the operation. Three patients had internal fixation failure after operation, and the internal fixation device was removed. Results The operation time was 30 to 65 min, and the blood loss was 15 to 40 ml. No important nerves, blood vessels, or organs were damaged. The imaging healing time was 3 to 6 months. According to the Rockwood functional score, the total score was (13.50±1.86), pain (2.57±0.50), range of motion (2.78±0.41), muscle strength (2.93±0.28), restricted daily activity (2.85±0.35), subjective results (2.63±0.61);the results were excellent in 20 cases, good in 3 cases, fair in 1 case.@*CONCLUSION@#Proximal clavicular fracture is a type of fracture with low incidence. According to different fracture types, different internal fixation methods and treatment methods can be selected, and satisfactory surgical results can be achieved.

Diversity of the T cell receptor β chain complementarity-determining region 3 in peripheral blood of neonates with sepsis: an analysis based on immune repertoire sequencing / 中国当代儿科杂志

OBJECTIVES@#To investigate the diversity of peripheral blood T cell receptor (TCR) β chain complementarity-determining region 3 (CDR3) based on immune repertoire sequencing in neonates with sepsis and the possible pathogenesis of neonatal sepsis.@*METHODS@#A total of 12 neonates with sepsis were enrolled as the case group, and 9 healthy full-term infants, matched for gestational age, birth weight, and age, were enrolled as the control group. Omega nucleic acid purification kit (SQ blood DNA Kit II) was used to extract DNA from peripheral blood samples, TCR β chain CDR3 was amplified by multiplex PCR, and then high-throughput sequencing was performed for the products to analyze the diversity of TCR β chain CDR3 and the difference in expression.@*RESULTS@#The length and type of TCR β chain CDR3 were similar between the case and control groups, and Gaussian distribution was observed in both groups. With D50 and Shannon-Wiener index as the evaluation indices for diversity, the case group had a significantly lower diversity of TCR β chain CDR3 than the control group (@*CONCLUSIONS@#There is a significant change in the diversity of TCR β chain CDR3 in the peripheral blood of neonates with sepsis, suggesting that it might be associated with the immune pathogenesis of neonatal sepsis.

Preliminary development of guided template of middle and upper thoracic percutaneous vertebroplasty in thoracic pedicle approach due to three dimentional soft tissue print technique / 中国骨伤

OBJECTIVE@#To investigate the feasibility of a drill template for the placement of guided template of middle and upper thoracic percutaneous vertebroplasty in thoracic pedicle approach on digital design and 3D printing technology.@*METHODS@#The preoperative CT images of 20 patients with thoracic fracture were collected retrospectively. With the 3D soft tissue printing technology, the data was reconstructed by 3D imaging reconstruction software to produce 1∶1 three dimensional soft tissue model. The pedicle screw channel and the digital template were designed by the 3-matic module of Mimics15.0 software. After guide template was printed by 3D printer and three dimensional template was fixed on the model, 2.0 mm Kirschner was placed and the accuracy of a drill template was observed by CT scans, bone cement was injected through the puncture tube and verified with images. The time of nail guide design, guide template production and cost were recorded.@*RESULTS@#The effectiveness of three dimensional thoracic model and digital guided template of middle and upper thoracic percutaneous vertebroplasty of thoracic fractures in thoracic pedicle approach was confirmed. Kirschner was placed and the accuracy of screw placement was confirmed with CT scanning. Template and the corresponding anatomical landmark fitted well, bone cement had showed good filling. The average printing time of upper thoracic spine model with soft tissue, the mean time of nail guide design, guide template production and cost were (719.00±3.03) min, (12.30±1.01) min, (55.50±10.30) min and RMB 3 150 yuan on average respectively.@*CONCLUSION@#By means of individual design and 3D soft tissue printingtechnology, accurate placement of guided template of middle and upper thoracic percutaneous vertebroplasty could be realized.

Surgical treatment of capitellum and trochlea fractures in adult through Kaplan approach associated with anteromedial approach / 中国骨伤

OBJECTIVE@#To investigate the surgical treatment and outcome of capitellum and trochlea fractures in adult through Kaplan approach associated with anteromedial approach.@*METHODS@#From September 2012 to September 2016, 15 patients with capitellum and trochlea fractures were treated by Kaplan approach associated with anteromedial approach. Of the 15 cases, there were 6 males and 9 females, aged from 21 to 69 years old, with a mean of (42.0±10.5) years old. Eight patients had fractures on the left and 7 patients on the right. All the fractures were classified into type IIA(5 cases), type IIIA(4 cases) and type IIIB (6 cases) according to Dubberley classification. The results were evaluated by Mayo elbow function score for analysis.@*RESULTS@#All the patients were followed up, the mean follow-up duration was(13.0±4.7) months(ranged 8 to 26 months). The mean Mayo elbow function score was 85.6±5.3(ranged 76 to 94). Postoperative follow-up had 4 cases excellent, 7 cases good, and 4 cases fair. Average arc of motion in elbow was(129.2±12.1)° in flexion and(6.6±1.9)° in extension.@*CONCLUSIONS@#The surgical treatment of capitellum and trochlea fractures in adult through Kaplan approach associated with anteromedial approach can better expose the fractures to achieve the satisfactory exposure and finish the surgical procedure, and the short-term outcome is satisfactory.

linical application of personalized 3D printing-guided template of intramedullary lag screw insertion on lateral superior ramous of pubic / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the efficacy and advantages of personalized 3D printing-guided template of lateral superior ramous of pubic intramedullary lag screw.</p><p><b>METHODS</b>From July 2015 to December 2016, 20 patients with the superior and inferior ramous of pubis fracture were treated with lag screws placement. All the patients were divided into test group(with guided template) and control group(with general operation). There were 7 males and 3 females with an average age of (46.20±3.03) years old in test group and 6 males and 4 males with (48.50±2.25) years old in control group. There were 6 cases and 5 cases of superior and inferior branches fractures of pubic on the left side and 4 cases and 5 cases on the right side in two groups respectively. The operation time, perspective times and bleeding loss were compared between two groups.</p><p><b>RESULTS</b>The test group and the control group had no statistically significant relative to gender, age, fracture classification. The average time of surgery, average intraoperative fluoroscopy times, mean blood loss in test group were (31.0±5.3) min, (3.5±2.1) times, (75.6±10.5) ml respectively, and in control group were(55.0±6.8) min, (27.6±3.2) times, (85.5±12.5) ml respectively. There were significant Statistical differences between two groups(<0.05) in average operation time and average fluoroscopy times, however, mean blood loss had no significant differences between two groups(>0.05).</p><p><b>CONCLUSIONS</b>The personalized guide template based on 3D printing technology could realize precise placement of the lateral intramedullary lag screw fixation in the superior branch of pubic, also could save the operation time and reduce the times of radiation exposure of patients and surgeons.</p>

Transplantation with three-dimensional spheroid-cultured mesenchymal stem cells down-regulates expression of TNF-α and apoptosis-related proteins in rats with cerebral ischemia/reperfusion injury / 第二军医大学学报

Objective To investigate the effect of the placenta-derived three-dimensional (3-D) spheroid-cultured mesenchymal stem cells (MSCs) on the expression of tumor necrosis factor-α (TNF-α) and apoptosis-related proteins in rats with cerebral ischemia-reperfusion injury, so as to explore the neuroprotective effects and mechanism of 3-D spheroid-cultured MSCs. Methods The experimental animals were randomly divided into Sham group, Vehicle group and 3-D spheroid-cultured MSCs treated group (n=36). In the Sham group, the middle cerebral artery (MCA) was simply isolated but not ligated. In the MSC treated group, focal ischemia/reperfusion in rats was induced by intraluminal middle cerebral artery occlusion (MCAO) with a nylon monofilament suture and then MSCs transplantation was done. In the Vehicle group, the MCAO model was set up and an equal volume of vehicle was given. Neurological scores of animals were evaluated at different time points: the first day, the third day and the seventh day after surgery. Enzyme-linked immunosorbent assay (ELISA) and RT-PCR method were used to detect TNF-α expression in rat brain tissues. The SABC immunohistochemical staining method was used to detect the expression of Caspase-3 and Caspase-8 in rat brain tissues. Results The neuromotor function of rats in MSCs treated group was significantly decreased compared with those in the other two groups (P <0.05). Compared with the Sham group, the expressions of TNF-α, Caspase-3 and Caspase-8 in the brain tissue were significantly increased in the Vehicle group (P <0.01). Moreover, compared with the Vehicle group, expression of TNF-α, Caspase-3 and Caspase-8 in the brain tissue was significantly decreased in MSCs treated group (P <0.05, P <0.01). Conclusion 3-D spheroid-cultured MSCs transplantation may improve the neuromotor function in rats with cerebral ischemia/reperfusion injury via down-regulating inflammatory cytokine TNF-α and expression of Caspase-3 and Caspase-8 in the brain tissue.