1.Stress Field of the Meniscus under Different Knee Brace Conditions in Jumping Motion:A Numerical Study
Jiangtao RUAN ; Yangyang MENG ; Yinguang ZHANG ; Xia XIAO
Journal of Medical Biomechanics 2024;39(1):111-117
Objective The biomechanical model for the musculoskeletal system of a human knee joint was established using a numerical simulation method.The kinematic and dynamic information captured during jumping motion simulated by the human dynamic model was used as driven data of the knee biomechanical model,followed by further analysis of the stress field distribution characteristics of the meniscus under different thermal-force coupling knee brace conditions.Methods Based on computed tomography and magnetic resonance imaging of the subject,a realistic human knee model,including bone,articular cartilage,meniscus,ligaments and peripheral soft tissues of the knee joint,was constructed.Furthermore,two gaits,namely taking-off and landing-on,of jumping motion with an increased risk of meniscus injuries were selected according to mechanical features in full-cycle jumping motion.Subsequently,the stress field characteristics of the knee meniscus under four different thermal-force coupling knee braces were analyzed,the changes of the peak stress of the meniscus and its stress concentration area were discussed,and the protective efficacy and mechanical basis of meniscal injuries and wearing knee braces were explored.Results The anterior part of the medial knee meniscus was a vulnerable area under concentrated stress.Under the knee brace thermal-force coupling condition,the stress concentration area of the medial meniscus was transferred from its narrow and weak anterior part to its wide and thick middle part,and the peak stress was also significantly reduced.The peak stress on the medial meniscus and that on the lateral meniscus were similar,indicating that the two parts of the meniscus bore the external load evenly,and the meniscus stress concentration area decreased.Conclusions Thermal-force coupling knee braces have good protective effects against knee meniscus injury.The numerical simulation provides theoretical support and technical guidance for the design of multifunctional thermal knee braces.
2.Predictive value of bedside diaphragmatic ultrasound for pulmonary complications after thoracoscopic lobectomy
Gaofeng GUO ; Xiaoguo RUAN ; Yangyang WANG ; Jiaqiang ZHANG
The Journal of Practical Medicine 2024;40(2):207-212
Objective To assess the predictive value of bedside diaphragmatic ultrasound in predicting pulmonary complications(PPCs)after thoracoscopic lobectomy.Methods The patients who had undergone elective thoracoscopic lobectomy in Henan Provincial People's Hospital were collected.General information and perioperative indicators were recorded.Diaphragmatic motility was detected by bedside ultrasound preoperatively and on postopera-tive days 1,3,and 5.The patients were divided into two groups(PPCs group and non-PPCs group).Statistically different parameters in univariate analysis were included in multivariate logistic regression analysis to screen inde-pendent influencing factors of PPCs.Receiver operating curve(ROC)was drawn,and the performance of diaphragm ultrasound for predicting PPCs was evaluated by the area under the curve(AUC).Results 949 patients were included in this study.PPCs occurred in 537 patients(57.5% ).Univariate analysis showed that as compared with the non-PPCs group,the proportion of diabetic patients and postoperative VAS score in the PPCs group increased,time to chest tube removal and one-lung ventilation,and postoperative hospital stay were longer.PPCs group had a lower DE value on the operative side and healthy side on postoperative days 1 and 3 and on the operative side alone on day 5(P<0.05).Multivariate logistic regression analysis showed that prolonged one-lung ventilation time,diabetes mellitus,DE values on the operative side and unoperative side on postoperative days 1 and 3,and decreased DE value on the operative side on day 5 were independent risk factors for PPCs.The ROC curve shows that the efficacy of DE for pre-dicting PPCs on the operative and healthy sides on postoperative days 1 and 3 was relatively high(AUC of 0.797,0.821,0.933,and 0.929;respectively).The efficacy of DE for predicting PPCs on the operative side was poor on postoperative day 5(AUC of 0.703 and 0.512,respectively).Conclusions A decrease in postoperative DE,prolonged one-lung ventilation time,and diabetes are independent risk factors for PPCs after thoracoscopic lobectomy.Bedside ultrasound evaluation of DE has a higher value in predicting PPCs three days after surgery.
3.Characteristics of cervical lesions in 1 080 patients with abnormal colposcopic biopsies of TCT and HPV double screening in Shihezi region
Yangyang RUAN ; Yan WEI ; Jishuai HOU ; Rui BAI ; Xiaohan XU ; Ping YANG
Journal of Chinese Physician 2022;24(1):29-34
Objective:To explore the characteristics of cervical lesions in female patients in the Shihezi region of Xinjiang in the past two years and provide guidance for clinical work and local cervical cancer screening.Methods:The clinicopathological data and characteristics of 1 080 patients with abnormal double screening of human papilloma virus (HPV) and cervical exfoliative cell test (TCT) and vaginal mirror cervical tissue biopsy in the gynecology department of the First Affiliated Hospital of Medical College of Shihezi University from May 2017 to March 2019 were analyzed retrospectively. The influencing factors of cervical lesions were analyzed by logistic regression.Results:(1) Uneducated [odds ratio ( OR)=2.267], irregular vaginal bleeding ( OR=3.275) and number of sexual partners ≥3 ( OR=3.052) were independent risk factors for cervical lesions. (2) Cervical intraepithelial neoplasia (CIN) was detected most frequently in the 30-39 age group (57.54%), and cervical cancer was detected most frequently in the ≥60 age group (14.15%), followed by the 40-49 age group (2.20%). (3) The proportion of HPV positive and the positive rate of high-risk HPV16/18 in the 40-49 age group were the highest, 33.18% and 39.38% respectively. There was no statistically significant difference in HPV viral load between the different age groups ( P>0.05). (4) The detection rates of CIN3 and cervical cancer were higher in the HPV16/18-positive group than in the HPV-positive and TCT≥atypical squamous epithelial cells of undermined significance (ASC-US) group (18.34% vs 11.33%, 4.30% vs 1.82%), with statistically significant difference (all P<0.05), respectively. The detection rate of CIN2 was higher in the high-load group (28.44%) than in the medium-load group (25.32%) and the low load group (15.79%). (5) The detection rate of CIN3 in the HPV-positive TCT for the ASC-US populations was significantly higher in the HPV16/18-positive group than in the other subtypes of HPV-positive group (21.43% vs 8.33%, P<0.05). Conclusions:During cervical cancer screening in Shihezi region, we should strengthen the publicity of elderly women and uneducated people. CIN and cervical carcinoma in Shihezi region are closely associated with high-risk HPV infection, especially HPV16/18 infection. HPV-positive age is mainly concentrated in the age group of 40-49 years, and the detection rate of CIN and cervical cancer is the highest in the age group of 30-39 years and ≥60 years, respectively. The detection rate of ≥CIN2 in HPV16/18 fraction and high viral load population is higher than that of other HPV subtypes positive and low to medium load populations. How to effectively shunt HPV positive TCT is an important problem in ASC-US population, which needs further research.