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.

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.

Biomechanical study of the stability of subaxial cervical anterior transpedicular screw fixation for three-column injury / 中国骨伤

<p><b>OBJECTIVE</b>To compare the stability of subaxial cervical anterior transpedicular screw(ATPS) fixation and three traditional fixations for three-column injury.</p><p><b>METHODS</b>Six specimens of cervical spine were prepared. After measurememt of the range of motion(ROM) in intact state, the specimens were made into three-column injury models. The models were reconstructed with an anterior cervical cage, and stabilized by ATPS, anterior plate(AP), anterior plate + lateral mass screw(AP+LMS) and posterior transpedicular screw(PTPS). The ROM of the models in the four states were measured, and the results of data were compared after standardization.</p><p><b>RESULTS</b>The normalized ROM of ATPS state in flexion-extension, lateral bending, axial rotation were(77.17±4.75)%, (82.00±2.61)%, (83.17±2.23)%, which were significant small than those in intact state(<0.05). The normalized ROM of AP state in flexion-extension, lateral bending, axial rotation were(119.67±7.42)%, (116.33±7.53)%, (112.67±5.99)% , which were significant larger than those in intact state(<0.05). The normalized ROM of AP in all directions were significant larger than those of ATPS(<0.05). There was no significant difference between normalized ROM of PTPS state and those of ATPS state in flexion-extension and lateral bending(>0.05). The normalized ROM of PTPS state in axial rotation was(6.83±2.48)% and was significant larger than that of ATPS state(=0.009). The normalized ROM of AP+LMS state in flexion-extension was(68.50±2.43)%, which was significant smaller than that of ATPS state(=0.003). There was no significant difference between the normalized ROM of AP+LMS state and those of ATPS state in lateral bending and axial rotation(>0.05).</p><p><b>CONCLUSIONS</b>Subaxial cervical three-column injury model reconstruction by ATPS can provide the adequate primary stability, of which biomechanics property is superior compared to AP and PTPS, and is similar to that of AP+LMS. It can be applied to the patients with no need to decompression and reduction through posterior approach.</p>

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>

Preliminary development of drill template-assisted placement of reverse intramedullary lag screw for superior ramus of pubis using three dimentional print technique / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the feasibility of a drill template for the placement of reverse intramedullary lag screws on the outside of the pubis based on digital design and 3D printing technology.</p><p><b>METHODS</b>The preoperative CT images of a 23-year-old male patient with pelvic fracture were collected retrospectively. According to the Young and Burgess classification, the type of pelvic fracture was LC IIwith the 3D printing technology. The data was reconstructed by 3D imaging reconstruction software to produce 1:1 three dimensional model. The screw channel and the individual drill template was designed by the softwares of Mimics 10.01 and Geomagic 12, the accuracy of a drill template was observed by X-rays and CT scans after the placement of 2.0 mm K-wires in the three dimensional template fixed on the model.</p><p><b>RESULTS</b>Three dimensional pelvic model and digital, individual drill template could meet the requirement of the placement of reverse interamodullary lay screw for the treatment of superior ramus of pubis fracture. K-wire was placed and the accuracy of screw placement was confirmed using the X-ray and CT scanning. Template and the corresponding anatomical landmark fitted well.</p><p><b>CONCLUSIONS</b>With the assistance of the individual design and 3D printing technology, the accurate placement of superior ramus of pubis fracture screws can be realized. This technology is helpful to reduce the operation time and X-ray exposure of the patients and doctors.</p>

Detection and identification of human metapneumovirus by real time reverse transcription PCR / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To develop a rapid, sensitive and specific real time reverse transcription PCR for detecting and identifying human metapneumovirus.</p><p><b>METHODS</b>The Hmpv-L gene of human metapneumovirus was chosen as target gene, the primers and TaqMan probe were designed, and the PCR reaction was optimized systematically. The total RNA was extracted from respiratory specimens, and reverse transcription was performed through random primer. The cDNA was detected by using real time PCR. The specificity, sensitivity and reproducibility of real time PCR were estimated. The real time PCR was applied to detect 180 clinical respiratory specimens.</p><p><b>RESULTS</b>The human metapneumovirus can be detected using real time reverse transcription PCR accurately and quickly, and the sensitivity was 1 copy/microl. The coefficient of variation of intra-assay and inter-assay was less than 5%. Among those 180 specimens, 28 (15.56%) were positive for human metapneumovirus, the clinical diagnoses for these 28 patients were pneumonia (15.60%, 17/109) and bronchiolitis (15.49%, 11/71). 21 positive specimens were from patients under 2 years of age, and 6 positive specimens were from patients between 2 and 5 years of age, only 1 positive specimens was from patients over 5 years.</p><p><b>CONCLUSION</b>It is demonstrated that real time reverse transcription PCR is a reliable, accurate and feasible assay for human metapneumovirus, which has become one of the most important pathogens induced acute respiratory infections in pediatric patients.</p>