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Objective To compare the biomechanical characteristics of medial and lateral locking plates for Schatzker typeⅥfractures of tibial plateau by finite element analysis. Methods A 38 year-old male volunteer was enrolled for CT scan of his lower limbs. His CT images of the left tibial plateau were used for 3D reconstruction of a model of Schatzker type Ⅵ fracture by NX 9.0 software. After the boundary con-ditions were set, a 500 N load was applied to the tibial plateau to simulate the stress on a single leg when an adult weighing 60 kg walked. The displacement and stress on plate and screws were analyzed by Abaqus software. Results The ultimate stress on the model fixated with a medial locking plate was 81.7 MPa, located at the proximal tibiofibular joint surface. The ultimate stress on the model fixated with a lateral locking plate was 487.4 MPa, located at the junction of plate and screws. The ultimate stress on the fibula was much larger in the model fixated with a medial locking plate than in the model fixated with a lateral locking plate. The ultimate displacement was smaller and more homogeneous in the model fixated with a medial locking plate (1.15 mm) than in the model fixated with a lateral locking plate (3.44 mm).Conclusion The Schatzker type Ⅵ fractures of tibial plateau should be fixated with a medial locking plate because it has more biomechanical advantages than a lateral locking plate.
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Objective To investigate the accuracy of CT in the diagnosis of central lung cancer and the clinical significance of magnetic resonance imaging ( MRI) supplementary diagnosis ,in order to provide reference for clinical diagnosis.Methods From January 2015 to October 2017,30 patients with suspected central lung cancer treated in General Hospital of Lingchuan County Medical Group were selected in the research .All patients were examined by CT and MRI ,and the results of pathological examination were taken as the standard .The results of CT and MRI were observed and the value of MRI supplementary examination in CT diagnosis was analyzed .Results The sensitivity,specificity and accuracy of CT in the diagnosis of central lung cancer were 68.0％,20.0％and 60.0％, respectively .After MRI imaging supplementary diagnosis , the diagnostic sensitivity , specificity and accuracy of diagnosis of central lung cancer were 92.0％,80.0％ and 90.0％, respectively.Conclusion The accuracy of diagnosis of central lung cancer by CT is low .In order to ensure the accuracy of diagnosis ,it is necessary to carry out MRI supplementary diagnosis to the patients .
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Objective To observe the MSCT features of invasive pulmonary tuberculosis,and to investigate its effect on the prognosis.Methods 60 patients with invasive pulmonary tuberculosis were selected as the study subjects.The gold standard was in sputum culture and histopathology.The clinical value of MSCT in the diagnosis of invasive pulmonary tuberculosis was evaluated.The distribution and morphological characteristics of the lesions in the invasive pulmonary tuberculosis were observed and analyzed.The patients were divided into the treatment group and the death group.The morphological changes of lung lesions were compared between the two groups.Results In 60 patients,a total of 45 patients with invasive pulmonary tuberculosis were diagnosed,MSCT of infiltrating pulmonary tuberculosis diagnostic sensitivity,specificity,positive predictive rate,negative predictive rate,correct rate,misdiagnosis rate,missed diagnosis rate,diagnostic accordance rate were 93.3%,80.0%,93.3%,80.0%,73.3%,20.0%, 6.7%,90.0%,respectively.On the lung multiple patchy shadow,real change shadow,multiple nodules,cavity shadow, on the unilateral lung syndrome,and branch sign and halo sign is the main sign of invasive pulmonary tuberculosis. Before treatment,MSCT signs of deterioration of chest between the treatment group and death group had no statistically significant difference(P>0.05).After 4 weeks of treatment,the proportion of effusion lesions in the treatment group was significantly decreased compared with before and during the same period of treatment(37.5%vs 76.9%;3.1%vs 92.3%),the differences were statistically significant(χ2 =5.750,16.541,all P<0.05).After 8 weeks of treat-ment,the proportions of effusion,nodules and cavity lesions in the treatment group were significantly lower than those in the deteriorated group(3.1% vs 92.3%;0.0% vs 15.4%;6.2% vs 38.5%),the differences were statistically significant (χ2 =16.541,5.152,7.302,all P<0.05).Conclusion Morphological changes of MSCT in invasive pulmonary tuberculosis have certain characteristics.In the diagnosis,differential diagnosis and therapeutic evaluation of invasive pulmonary tuberculosis,MSCT has high value.
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<p><b>BACKGROUND</b>Although the use of an intramedullary fibular allograft together with locking plate fixation can provide additional medial support and prevent varus malalignment in displaced proximal humeral fractures with promising results, the fibular autograft donor site often sustains significant trauma and cannot restore the articular surface of comminuted fractures. The aim of this study was to evaluate the clinical and radiographic outcomes of a locking plate and crest bone autologous graft for treating proximal humerus comminuted fractures.</p><p><b>METHODS</b>We assessed the functional outcomes and complication rates in 40 patients with proximal humerus comminuted fractures. Eighteen patients were treated with a locking plate and an autologous crest bone graft (experimental group), and 22 were treated with only the locking plate and no bone graft (control group). Postoperative assessments included radiographic imaging, range of motion analysis, pain level based on the visual analogue scale (VAS), and the SF-36 (Short Form (36) Health Survey), as well as whether patients could return to their previous occupation.</p><p><b>RESULTS</b>All fractures healed both clinically and radiologically in the experimental group. There was no more than 2 mm collapse of the humeral head, and no osteonecrosis or screw penetration of the articular surface. In contrast, two patients had a nonunion in the control group, and they eventually accepted total shoulder replacements. The average time from surgery to radiographic union was significantly shorter in the experimental group ((4.66±1.63) months) compared with the control group ((5.98±1.57) months) (P < 0.05). For the experimental versus controls groups, the mean shoulder active flexion (148.00±18.59 vs. 121.73±17.20) degrees, extension (49.00±2.22 vs. 42.06±2.06) degrees, internal rotation (45.00±5.61 vs. 35.00±3.55) degrees, external rotation (64.00±9.17 vs. 52.14±5.73) degrees, and abduction (138.00±28.78 vs. 105.95±15.66) degrees were all significantly higher (all P < 0.001). The median SF-36 in the experimental group ((88.00±5.71) points) was significantly higher than that of the control group ((69.45±9.45) points; P < 0.001). The median VAS pain level (mean rank, 10.50) in the experimental group was lower than that (mean rank, 47.19) of the control group (P < 0.001). All but one patient (17 of 18, 94.4%) in the experimental group returned to their previous activities or occupations, and that one patient changed to a different occupation because of slight restrictions to activities. On the other hand, four patients could not return to their previous activities or occupations in the control group.</p><p><b>CONCLUSION</b>Locking plate fixation combined with an iliac crest bone graft is an effective technique for treating proximal humerus comminuted fractures.</p>