Biomechanical analysis of internal fixation system stability for tibial plateau fractures.

Background: Complex bone plateau fractures have been treated with bilateral plate fixation, but previous research has overemphasized evaluating the effects of internal fixation design, plate position, and screw orientation on fracture fixation stability, neglecting the internal fixation system's biomechanical properties in postoperative rehabilitation exercises. This study aimed to investigate the mechanical properties of tibial plateau fractures after internal fixation, explore the biomechanical mechanism of the interaction between internal fixation and bone, and make suggestions for early postoperative rehabilitation and postoperative weight-bearing rehabilitation. Methods: By establishing the postoperative tibia model, the standing, walking and running conditions were simulated under three axial loads of 500 N, 1000 N, and 1500 N. Accordingly, finite element analysis (FEA) was performed to analyze the model stiffness, displacement of fractured bone fragments, titanium alloy plate, screw stress distribution, and fatigue properties of the tibia and the internal fixation system under various conditions. Results: The stiffness of the model increased significantly after internal fixation. The anteromedial plate was the most stressed, followed by the posteromedial plate. The screws at the distal end of the lateral plate, the screws at the anteromedial plate platform and the screws at the distal end of the posteromedial plate are under greater stress, but at a safe stress level. The relative displacement of the two medial condylar fracture fragments varied from 0.002-0.072 mm. Fatigue damage does not occur in the internal fixation system. Fatigue injuries develop in the tibia when subjected to cyclic loading, especially when running. Conclusion: The results of this study indicate that the internal fixation system tolerates some of the body's typical actions and may sustain all or part of the weight early in the postoperative period. In other words, early rehabilitative exercise is recommended, but avoid strenuous exercise such as running.

Interactions between vaginal local cytokine IL-2 and high-risk human papillomavirus infection with cervical intraepithelial neoplasia in a Chinese population-based study.

Background: Although interleukin-2 (IL-2) has long been associated with cancer development, its roles in the development of cervical cancer remains unclear. Few studies examined the associations between IL-2 and high-risk human papillomavirus (HPV) with risk of cervical intraepithelial neoplasia (CIN). Objective: We aimed to assess the association of IL-2 and high-risk HPV infection with risk of CIN as well as their interactions on the risk of CIN. Design: We performed a cross-sectional analysis of screening data in 2285 women aged 19-65 years who participated in an ongoing community-based cohort of 40,000 women in Shanxi, China in 2014-2015. Both categorical and spline analyses were used to evaluation the association between IL-2 in the local vaginal fluids and prevalence of CIN. In addition, 1503 controls were followed up until January 31, 2019), the nested case-control study design was adopted to evaluate the association of vaginal lavage IL-2 levels and the risk of CIN progression. Results: After adjusting for potential confounders, IL-2 levels were statistically inversely associated with prevalence of CIN (the 1st versus 4th quartile IL-2 levels: the respective odds ratio [OR] and 95% confidence intervals [CI] was: = 1.75 [1.37, 2.23] for CIN, 1.32 [1.01, 1.73] for CIN I, and 3.53 [2.26, 5.52] for CIN II/III). Increased IL-2 levels were inversely associated with prevalence of CIN (P-overall<0.01, P-nonlinearity<0.01 for CIN; P-overall<0.01, P-nonlinearity = 0.01 for CIN I; P-overall <0.01, P-nonlinearity = 0.62 for CIN II/III). The highest prevalence of CIN was observed in women with high-risk HPV, who also had the lowest IL-2 levels (P-interaction < 0.01). Nested case-control study observed an inverse association between IL-2 levels and risk of CIN progression (OR=3.43, [1.17, 10.03]). Conclusions: IL-2 levels in the local vaginal fluids were inversely associated with the risk of CIN in Chinese women either with or without high-risk HPV infection.

Design of Personalized Cervical Fixation Orthosis Based on 3D Printing Technology.

The movement of the cervical spine should be restricted throughout the rehabilitation phase after it has been injured. Cervical orthosis is commonly utilized in clinical settings to guarantee cervical spine stability. However, to date, the investigations are limited to patient-specific cervical fixation orthoses. This study provides a new idea for making personalized orthoses. The CT data of the patient's cervical spine were collected, then mimics were used for reconstructing the skin of the cervical spine, the Geomagic Studio was used for surface fitting, the Inspire Studio was used for structural topology optimization, redundant structures were removed, the resulting orthotics were postprocessed, and finally, it was printed with a 3D printer. No signs of pain or discomfort were observed during the wearing. The cervical spine range of motion in flexion, extension, lateral flexion, and rotation is all less than 8° after using the device. Low cost, quick manufacturing time, high precision, attractive appearance, lightweight structure, waterproof design, and practical customized orthotics for patients are all advantages of 3D printing technology in the field of orthopedics. Many possible benefits of using 3D printing to build new orthotics include unique design, stiffness, weight optimization, and improved biomechanical performance, comfort, and fit. Personalized orthotics may be designed and manufactured utilizing 3D printing technology.

Efficient combination of Human Papillomavirus Genotyping for the triage of women with Atypical Squamous Cells of Undetermined Significance in Chinese rural population: A population-based study.

Objective: In this prospective, population-based study, we evaluated the utility of high-risk human papillomavirus (HR-HPV) genotyping for triaging women with atypical squamous cells of undetermined significance (ASC-US) in the Chinese rural area. Methods: A total of 40,000 women were recruited from rural areas of Shanxi Province, China, between June 2014 and December 2014. Women with Pap results of ASC-US underwent HPV genotyping, colposcopy and histopathological examination. For those with normal cervixes or cervical intraepithelial neoplasia (CIN) 1 on the initial evaluation, a 2-year follow-up study was performed. Results: The reporting rate of ASC-US was 5.76% (2,304/40,000) in the study population. The detection rates of CIN 2 or above (CIN2+) and CIN 3 or above (CIN3+) in women with ASC-US were 7.28% and 1.75%, respectively. HPV 16 (39.53%), HPV 58 (17.83%), and HPV 52 (15.50%) were the three most prevalent HR-HPV genotypes among all women with ASC-US cytology. The five most common HR-HPV genotypes in CIN3+ lesions were HPV16, HPV58, HPV33, HPV31 and HPV18. Compared with the 15 HR-HPV testing, genotyping for a combination of HPV16/18/31/33/58 increased specificity significantly with virtually no loss of sensitivity for detecting CIN2+ and CIN3+ lesions, as well as significantly reduced colposcopy referral rate (23.15% vs 33.70%, p<0.01). In addition, in the 2-year follow-up period, women with infection of HPV16, 18, 31, 33 or 58 genotypes were the most likely population (92%, 23/25) to develop CIN2 lesion. Conclusion: Our results demonstrate that genotyping for a combination of HPV16/18/31/33/58 provides a more efficient and cost-effective model to risk-stratify women with ASC-US in the Chinese rural population.