The lumbar intervertebral disc exhibits a complex physiological structure with interactions between various segments, and its components are extremely complex. The material properties of different components in the lumbar intervertebral disc, especially the water content (undergoing dynamic change as influenced by age, degeneration, mechanical loading, and proteoglycan content) - critically determine its mechanical properties. When the lumbar intervertebral disc is under continuous pressure, water seeps out, and after the pressure is removed, water re-infiltrates. This dynamic fluid exchange process directly affects the mechanical properties of the lumbar intervertebral disc, while previous isotropic modeling methods have been unable to accurately reflect such solid-liquid phase behaviors. To explore the load-bearing mechanism of the lumbar intervertebral disc and establish a more realistic mechanical model of the lumbar intervertebral disc, this study developed a solid-liquid biphasic, fiber-reinforced finite element model. This model was used to simulate the four movements of the human lumbar spine in daily life, namely flexion, extension, axial rotation, and lateral bending. The fluid pressure, effective solid stress, and liquid pressure-bearing ratio of the annulus fibrosus and nucleus pulposus of different lumbar intervertebral discs were compared and analyzed under the movements. Under all the movements, the fluid pressure distribution was closer to the nucleus pulposus, while the effective solid stress distribution was more concentrated in the outer annulus fibrosus. In terms of fluid pressure, the maximum fluid pressure of the lumbar intervertebral disc during lateral bending was 1.95 MPa, significantly higher than the maximum fluid pressure under other movements. Meanwhile, the maximum effective solid stress of the lumbar intervertebral disc during flexion was 2.43 MPa, markedly higher than the maximum effective solid stress under other movements. Overall, the liquid pressure-bearing ratio under axial rotation was smaller than that under other movements. Based on the solid-liquid biphasic modeling method, this study more accurately revealed the dominant role of the liquid phase in the daily load-bearing process of the lumbar intervertebral disc and the solid-phase mechanical mechanism of the annulus fibrosus load-bearing, and more effectively predicted the solid-liquid phase co-load-bearing mechanism of the lumbar intervertebral disc in daily life.
Humans ; Finite Element Analysis ; Intervertebral Disc/physiology* ; Lumbar Vertebrae/physiology* ; Weight-Bearing/physiology* ; Biomechanical Phenomena ; Stress, Mechanical ; Computer Simulation ; Models, Biological

Objective:To evaluate the relevant factors to optimize the learning curve and the impact of the basic skills of endoscopic technology on the learning curve of gasless transaxillary posterior endoscopic thyroidectomy.Methods:A retrospective analysis was performed to evaluate the clinical outcomes of 50 patients who underwent Glandular Ultrasound-Assisted (GUA) thyroid surgery by a surgeon with a background in endoscopic thyroid surgery via the thoracic-areolar approach, and 50 patients operated on by a surgeon without such experience at the Thyroid Surgery Department of Jilin University China-Japan Union Hospital from Apr. to Dec. 2023. The patients were divided into two groups: the Endoscopic Experience Group and the Non-Endoscopic Experience Group. The Cumulative Sum Control Chart (CUSUM) was applied to construct learning curves for both groups, dividing the technical exploration period from the mastery period. The analysis compared the surgical time, postoperative first-day drainage volume, number of central lymph nodes dissected rates, and postoperative complications between the two groups and across the two phases.Results:The analysis of the learning curve revealed that the inflection point of the Endoscopic Experience Group was 15, while of the Non-Endoscopic Experience Group was 18. The learning curve was divided into the technical exploration stage and the proficient mastery stage. The operative time of technical exploration stagde was significantly longer than of proficient mastery stage of both group (183.46±36.13min vs.144.40±26.14min, P<0.001; 186.89±48.91min vs.131.59±22.90min; P<0.001) . The operative time in the proficient mastery stage of the Endoscopic Experience Group was longer than that of the Non-Endoscopic Experience Group (144.40±26.15min vs. 131.59±22.90min, P<0.05) . The postoperative drainage volume in the Endoscopic Experience Group was lower than that in Non-Endoscopic Experience Group in both stages (65.40±32.48mL vs.93.22±30.67mL, 57.40±15.35mL vs.78.50±28.30mL, P<0.05) , and the postoperative drainage volume in the proficient mastery stage of the Non-Endoscopic Experience Group was significantly lower than in the technical exploration stage (93.22±30.67mL vs.78.50±28.30mL, P<0.05) .No significant differences in central lymph node dissection numbers or postoperative complications were observed between the groups at both stages. Conclusions:There is a specific learning curve in the early stage of gasless transaxillary posterior endoscopic thyroidectomy. After crossing the learning curve, the operation time is obviously shortened with the improvement of the operator's surgical technique.Having a basic understanding of endoscopic technology in the early stage can reduce the occurrence of postoperative drainage, but has a minimal impact on the learning curve.

Objective:To evaluate the relevant factors to optimize the learning curve and the impact of the basic skills of endoscopic technology on the learning curve of gasless transaxillary posterior endoscopic thyroidectomy.Methods:A retrospective analysis was performed to evaluate the clinical outcomes of 50 patients who underwent Glandular Ultrasound-Assisted (GUA) thyroid surgery by a surgeon with a background in endoscopic thyroid surgery via the thoracic-areolar approach, and 50 patients operated on by a surgeon without such experience at the Thyroid Surgery Department of Jilin University China-Japan Union Hospital from Apr. to Dec. 2023. The patients were divided into two groups: the Endoscopic Experience Group and the Non-Endoscopic Experience Group. The Cumulative Sum Control Chart (CUSUM) was applied to construct learning curves for both groups, dividing the technical exploration period from the mastery period. The analysis compared the surgical time, postoperative first-day drainage volume, number of central lymph nodes dissected rates, and postoperative complications between the two groups and across the two phases.Results:The analysis of the learning curve revealed that the inflection point of the Endoscopic Experience Group was 15, while of the Non-Endoscopic Experience Group was 18. The learning curve was divided into the technical exploration stage and the proficient mastery stage. The operative time of technical exploration stagde was significantly longer than of proficient mastery stage of both group (183.46±36.13min vs.144.40±26.14min, P<0.001; 186.89±48.91min vs.131.59±22.90min; P<0.001) . The operative time in the proficient mastery stage of the Endoscopic Experience Group was longer than that of the Non-Endoscopic Experience Group (144.40±26.15min vs. 131.59±22.90min, P<0.05) . The postoperative drainage volume in the Endoscopic Experience Group was lower than that in Non-Endoscopic Experience Group in both stages (65.40±32.48mL vs.93.22±30.67mL, 57.40±15.35mL vs.78.50±28.30mL, P<0.05) , and the postoperative drainage volume in the proficient mastery stage of the Non-Endoscopic Experience Group was significantly lower than in the technical exploration stage (93.22±30.67mL vs.78.50±28.30mL, P<0.05) .No significant differences in central lymph node dissection numbers or postoperative complications were observed between the groups at both stages. Conclusions:There is a specific learning curve in the early stage of gasless transaxillary posterior endoscopic thyroidectomy. After crossing the learning curve, the operation time is obviously shortened with the improvement of the operator's surgical technique.Having a basic understanding of endoscopic technology in the early stage can reduce the occurrence of postoperative drainage, but has a minimal impact on the learning curve.

BACKGROUND:Avascular necrosis of the femoral head is a refractory orthopedic disease that seriously affects the normal life of patients.Hip preservation is recommended for young patients due to the limited prosthesis longevity and revision.Accurate prediction of the mechanical properties of the necrotic area in the early stage and then intervention is the key to hip preservation. OBJECTIVE:To establish a dynamic contact mechanics finite element model of necrotic femoral head based on human hip CT data and predict effects of both necrotic volume magnitude and its position on biomechanics of the necrotic region under walking movement. METHODS:CT data of a volunteer were collected and then geometry model of the hip was rebuilt.Finite element model of the necrotic femoral head was established using the Abaqus software.Nine different necrotic femoral models were constructed by combined both three different necrotic volume magnitudes(small,medium and big volume)and three different necrotic positions(coincided with,medium deviated with and kept away from the line of the force).The Von Mises of the necrotic region for all models were predicted under both 3 000 N static load and dynamical loads of one whole ISO walking gait cycle.The collapse risk for all models was evaluated based on collapse criterion. RESULTS AND CONCLUSION:(1)More approaching of the necrotic region to the line of force and bigger collapse volume made the maximum Von Mises increasing.This also enlarged the collapse risk of the necrotic region.(2)For different load types,walking movement increased the maximum Von Mises of the necrotic region than that of the value under static load under the same necrotic volume and location.(3)In conclusion,dynamic load would result in increasing of the maximum Von Mises of the necrotic region comparing to static load during exercise.Therefore,the risk of local collapse will increase due to greater Von Mises.However,the overall collapse risk is lower than that of static load due to the dynamic change of bearing area.This factor should be carefully considered by surgeons when they evaluate the mechanical performance of the necrotic femoral head.

Differentiated thyroid carcinoma (DTC) is the most common endocrine tumor,characterized by high incidence,low recurrence rate,and low mortality. Locally advanced thyroid cancer (LATC) is rare in clinical practice,with poor prognosis,and is one of the leading causes of death among thyroid cancer patients. In August 2024,the Thyroid Surgery Department of China-Japan Union Hospital of Jilin University admitted a 61-year-old male patient with a history of "neck mass surgery 16 years ago and progressive enlargement with ulceration of the mass over the past 3 months." Physical examination revealed an irregularly shaped mass measuring approximately 12 cm × 12 cm in the left supraclavicular fossa,with a dark red surface,ulceration,bleeding,and necrotic exudate in some areas. After admission,a multidisciplinary team (MDT) consultation was initiated,and the patient underwent his fifth surgery,which included resection of the left cervical mass,left cervical lymphadenectomy,resection of a submental mass,and free flap transplantation. The patient was discharged on postoperative day 10 in good condition. One month after surgery,a follow-up ultrasound at our hospital showed no significant abnormalities in the neck,with good healing of the local skin and survival of the transplanted flap. This article reviews the MDT treatment process of this LATC case and summarizes the characteristics of LATC based on domestic and international literature,providing experience and references for the comprehensive treatment of this disease.

Differentiated thyroid carcinoma (DTC) is the most common endocrine tumor,characterized by high incidence,low recurrence rate,and low mortality. Locally advanced thyroid cancer (LATC) is rare in clinical practice,with poor prognosis,and is one of the leading causes of death among thyroid cancer patients. In August 2024,the Thyroid Surgery Department of China-Japan Union Hospital of Jilin University admitted a 61-year-old male patient with a history of "neck mass surgery 16 years ago and progressive enlargement with ulceration of the mass over the past 3 months." Physical examination revealed an irregularly shaped mass measuring approximately 12 cm × 12 cm in the left supraclavicular fossa,with a dark red surface,ulceration,bleeding,and necrotic exudate in some areas. After admission,a multidisciplinary team (MDT) consultation was initiated,and the patient underwent his fifth surgery,which included resection of the left cervical mass,left cervical lymphadenectomy,resection of a submental mass,and free flap transplantation. The patient was discharged on postoperative day 10 in good condition. One month after surgery,a follow-up ultrasound at our hospital showed no significant abnormalities in the neck,with good healing of the local skin and survival of the transplanted flap. This article reviews the MDT treatment process of this LATC case and summarizes the characteristics of LATC based on domestic and international literature,providing experience and references for the comprehensive treatment of this disease.

Objective:To investigate the feasibility of simultaneous arteriovenous enhancement of neck CT with two-stage injection of contrast agent and its effect on image quality and radiation dose.Methods:A total of 30 patients undergoing neck CT enhancement scan due to space-occupying lesions in Beijing Tongren Hospital, Capital Medical University from February to April 2022 were prospectively included as the experimental group. The neck CT enhancement scan was performed with two-stage injection of contrast agent and arteriovenous simultaneous enhancement. The dosage of contrast agent was calculated according to the patient′s body weight, and the method of two-stage injection was adopted. The dosage of contrast agent in the first stage was 0.7 ml/kg, with normal saline in the middle stage, and the second stage (began at 35 s) was 0.3 ml/kg. A total of 30 patients with gender and age matching with the experimental group from December 2021 to January 2022 were retrospectively collected as the control group. The control group was treated with the traditional arterial phase and venous phase scanning method with the dosage of 1.0 ml/kg contrast agent. The arterial phase was scanned at the 30 s and the venous phase was scanned at the 60 s. The CT values of bilateral carotid arteries and jugular veins in the experimental group were measured, the CT values of bilateral carotid arteries in the arterial phase were measured in the control group, and the CT values of bilateral carotid arteries and jugular veins in the venous phase were measured. Carotid artery enhancement score was performed for images of experimental group and control group in arterial and venous phase, and jugular vein and lesion enhancement score was performed for images of experimental group and control group in venous phase. The effective dose was calculated for both groups. The difference of carotid artery CT values between images was compared by one-way analysis of variance, and LSD method was used for pairwise comparison. The CT values of jugular vein were compared using independent sample t test. Kruskal-Wallis test was used to compare carotid artery enhancement scores, and Nemenyi method was used for pairwise comparison. Jugular vein and lesion enhancement scores and effective dose were compared by Mann-Whitney U test. Results:The CT value of carotid artery of experimental group [left (276±24) HU, right (273±25) HU] was lower than that of control group in arterial phase [left (329±33) HU, right (327±32) HU], and higher than that in the venous phase [left (147±15) HU, right (148±16) HU]. All the differences were statistically significant ( P<0.001). The CT value of jugular vein of experimental group [left (206±18) HU, right (203±19)] was higher than that of control group in the venous phase [left (154±15) HU, right (151±15)], the difference was statistically significant ( t=11.88, 11.76, both P<0.001). There was no significant difference in carotid artery enhancement score between experimental group and control group in arterial phase ( P=0.624), but the carotid artery enhancement score of the experimental group was higher than that of the control group in the venous phase, and the difference was statistically significant ( P<0.001). The scores of jugular vein and lesion enhancement in experimental group were higher than those of control group in venous phase, and the difference was statistically significant ( Z=5.01, P<0.001). The effective dose of the experimental group [2.41(2.04, 2.72) mSv] was decreased by 52.2% compared with the control group [5.04(4.18, 5.44) mSv], and the difference was statistically significant ( Z=-6.24, P<0.001). Conclusions:The neck CT enhanced scan with two-stage injection of contrast agent and arteriovenous simultaneous enhancement method can obtain comprehensive images of arterial and venous phases, and realize simultaneous enhancement of carotid artery, jugular vein and lesions, and reduce radiation dose.

Objective:To investigate the risk factors and clinical significance of lymph nodes metastasis between sternocleidomastoid and sternohyoid muscle lymph node (LNSS) metastasis in thyroid cancer patients, so as to guide the reasonable dissection of LNSS region and lateral cervical lymph node in patients with papillary thyroid carcinoma (PTC) .Methods:We selected 111 PTC patients with lateral cervical lymph node metastasis who underwent radical thyroidectomy and lateral cervical lymph node dissection from Nov. 2018 to Dec. 2021 in China-Japan Union Hospital of jilin university. All patients were treated with low collar arc incision. Radical thyroidectomy and lateral cervical lymph node dissection were performed according to the guidelines, and lymph nodes in each district were grouped for pathological examination. According to whether LNSS metastasis occurred, they were divided into two groups: LNSS positive group (LNSS metastasis occurred) and LNSS negative group (LNSS metastasis did not happen). We collected the basic information of all 111 PTC patients with lateral lymph node metastasis (LLNM), preoperative color Doppler ultrasound examination and paraffin-embedded pathology and other related clinical case data. Then we described the clinicopathological features of cervical lymph node metastasis. Independent sample t test and Mann-Whitney U test were used for continuous variables, and Fisher exact test was used for data analysis for classified variables. Correlation analysis adopted binary logistics regression model, and analyzed the regularity and risk factors of LNSS metastasis. Results:In this study, the detection rate of LNSS was 64.9% (72/111), the overall LNSS metastasis rate was 7.2% (8/111), and the number of lymph node metastasis was 0-5. Univariate analysis showed that the location of LNSS metastasis was related with the cancer focus ( P<0.001), the preoperative serum thyroglobulin (Tg) level ( P=0.002), the number of lymph node metastasis in lateral cervical level Ⅳ ( P=0.001), the longest diameter of the cancer focus ( P=0.003) and the longest diameter of metastatic lymph nodes ( P=0.001) However, age, sex, whether there is lymph node metastasis in the central region (central lymph node metastasis ,CLNM), and whether there is multifocal cancer were not related to LNSS metastasis ( P≥0.05). Further multivariate analysis and work curve analysis of subjects showed that the tumor located in the lower pole ( P=0.014) and the number of lymph node metastasis in level Ⅳ more than 3 ( P=0.027) were independent risk factors for LNSS metastasis. It was found that the risk of LNSS metastasis increased when the cancer focus was located at the lower pole relative to the upper pole or middle part of the cancer focus ( OR=74.508, 95% CI: 2.373-2339.544). The number of lymph node metastasis in level Ⅳ had a positive effect on LNSS metastasis. The more lymph node metastasis in level Ⅳ, the higher the risk of LNSS metastasis ( OR=1.556; 95% CI=1.051-2.303) . Conclusions:In PTC patients with LLNM, the LNSS metastasis rate was 7.2%, and the advantages of LNSS cleaning outweigh the disadvantages. When the cancer focus is located at the lower pole and the number of lymph node metastasis in region Ⅳ is more than 3, it is necessary to pay attention to the dissection of this group of lymph nodes.

Objective:To investigate the value of the size-specific dose estimate (SSDE) on dose estimations of children's head CT scans.Methods:A retrospective study was conducted on plain head CT scans of 252 patients with the 64-row detector CT device of Discovery 750HD in the Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from January to September in 2019. The volume CT dose index (CTDI vol)values were recorded. The head circumference (HC), area, and CT value were measured using a self-developed computer program, and the water equivalent diameter (WED), size-specific conversion factors ( f293 and f220), and absorbed dose (SSDE 293 and SSDE 220) were calculated according to the AAPM reports 293 and 220.The patients were divided into three groups by the quartering meth odaccording to their HC(<47.8 cm, 47.8-52.7 cm, >52.7 cm)and four groups based on their ages(0-2, 3-6, 7-10 and 11-14 years old). The difference between parameters ( f220 and f293, SSDE 220 and SSDE 293、SSDE 293 and CTDI vol) were compared for different groups, and the correlation of HC with f293 and SSDE 293 was analyzed. Results:There was an overestimation of f220 by 11.11% ( t=252.61, P<0.05) compared with f293. SSDE 220 was overestimated by 10.31% ( t=228.21, P<0.05) compared with SSDE 293, and SSDE 293 was underestimated by 9.60% ( t=-31.34, P<0.05)compared with CTDI vol. For the three HC groups, SSDE 220 was overestimated by 8.54%, 10.37%, and 11.57% ( t=73.73, 438.58, 275.52, P<0.05)compared with SSDE 293, and SSDE 293 was underestimated by 1.30%, 9.79%, and 14.61% ( t=-1.91, -60.95, -47.64, P<0.05)compared with CTDI vol. For the four age groups SSDE 220 was overestimated by 8.45%, 10.00%, 10.57%, and 11.36% ( t=63.58, 232.29, 247.84, 302.95, P< 0.05)compared with SSDE 293, and SSDE 293 was underestimated by 1.49%, 8.27%, 10.63%, and 13.78% ( t=-1.83, -28.27, -37.30, -49.80, P< 0.05)compared with CTDI vol. Furthermore, HC was highly correlated with f293 and SSDE 293 ( r2=0.88 and 0.76, respectively, P< 0.05). Conclusions:The radiation dose in children′s head CT scanning can be more accurately estimated according to the AAPM Report 293, while it can be overestimated by CTDI vol. Meanwhile, the CT radiation dose can be patently overestimated with the AAPM Report 220 compared with Report 293.HC is closely correlated with f293 and SSDE 293 and it can be used to estimatee more accurately for SSDE and the radiation dose received by children during head CT scanning.

Echinococcosis is an age-old disease that causes serious damage to the animal husbandry and the human health perennially. As a newly discovered species of Echinococus, E. shiquicus has the potential public health significance and could be a potential parasitic zoonosis. In this review, its etiology, life cycle, epidemiology, detection and diagnoses, public health etc. are discussed or summarized. Also, a series of comparisons among E. granulosus, E. multilocularis and E. shiquicus are made.