OBJECTIVE: This review summarized the first 10-year progresses and controversies in the concept of anteromedial cortical support reduction, to provide references for further study and clinical applications. METHODS: Relevant domestic and foreign literature on cortical support reduction was extensively reviewed to summarize the definition of positive, neutral, and negative support, anteromedial cortices at the inferior corner, intraoperative technical tips for fracture reduction, radiographic assessment at different periods, comparison between positive versus neutral and medial versus anterior support, and the clinical efficacy of Chang reduction quality criteria (CRQC) and postoperative stability score. RESULTS: Anteromedial cortical support reduction was only focused on the cortex of anteromedial inferior corner, with no concern the status of lateral wall or lesser trochanter. Anteromedial cortex was seldom involved by fracture comminution, it was thicker, denser, and stronger, and was the key for mechanical buttress of the head-neck fragment to share compression load. Positive, neutral, and negative support were also called "extramedullary, anatomic, and intramedullary reduction", respectively. There was hardly seen parallel cortical apposition, but characterized by some kinds of head-neck rotation, for example 10°-15° flexed rotation for positive cortical contact and support. Due to intraoperative compression and postoperative impaction, the status of cortical support may be changed at different time of radiographic examination. The positive medial cortex support was more reliable with less reduction loss than its neutral counterpart, and the anterior cortex contact was more predictive than the medial cortex for final results. As incorporation the bearing of cortex apposition and using a 4-point score, CRQC demonstrated more efficacy and was gradually accepted and applied in the evaluation of trochanteric fracture reduction quality. Postoperative stability score (8 points) provided a assessment tool for early weight-bearing in safety to prevent mechanical failure. CONCLUSION Anteromedial cortical support reduction is a key point for stability reconstruction in the treatment of trochanteric femur fractures. Evidence has definitely shown that non-negative (positive and neutral) is superior to negative (loss of cortical support). There is a tendency that positive cortex support is superior to neutral, but high quality study with large sample size is needed for a clear conclusion.
Humans ; Femur/diagnostic imaging* ; Fracture Fixation, Internal/methods* ; Hip Fractures/diagnostic imaging* ; Treatment Outcome ; Fracture Fixation, Intramedullary/methods*

Panax ginseng, a perennial herbaceous plant and a representative of the Panax genus, is renowned for its exceptional medicinal value and economic benefits, often referred to as the “King of Herbs.” With the increasing market demand and the limited availability of suitable cultivation land, the issue of continuous cropping obstacles for P. ginseng has become increasingly prominent, directly hindering the sustainable development of the ginseng industry. This article summarizes the concept and hazards of continuous cropping obstacles and, drawing on the latest research, provides an in-depth analysis of the causes and response mechanisms. This work aims to establish a solid foundation for future research into the mechanisms of continuous cropping obstacles in P. ginseng.

Panax ginseng, a perennial herbaceous plant and a representative of the Panax genus, is renowned for its exceptional medicinal value and economic benefits, often referred to as the “King of Herbs.” With the increasing market demand and the limited availability of suitable cultivation land, the issue of continuous cropping obstacles for P. ginseng has become increasingly prominent, directly hindering the sustainable development of the ginseng industry. This article summarizes the concept and hazards of continuous cropping obstacles and, drawing on the latest research, provides an in-depth analysis of the causes and response mechanisms. This work aims to establish a solid foundation for future research into the mechanisms of continuous cropping obstacles in P. ginseng.

Panax ginseng, a perennial herbaceous plant and a representative of the Panax genus, is renowned for its exceptional medicinal value and economic benefits, often referred to as the “King of Herbs.” With the increasing market demand and the limited availability of suitable cultivation land, the issue of continuous cropping obstacles for P. ginseng has become increasingly prominent, directly hindering the sustainable development of the ginseng industry. This article summarizes the concept and hazards of continuous cropping obstacles and, drawing on the latest research, provides an in-depth analysis of the causes and response mechanisms. This work aims to establish a solid foundation for future research into the mechanisms of continuous cropping obstacles in P. ginseng.

BACKGROUND:The asymmetrical biomechanical environment of adolescent idiopathic scoliosis can lead to further wedge deformation of the vertebral body,which may affect cardiopulmonary function and compress nerves in severe cases.Adolescent idiopathic scoliosis with different degrees of scoliosis should be treated with exercise,bracing,and surgery.However,the mechanical mechanism of selecting an orthopedic approach remains unclear due to the individual variability of patients.OBJECTIVE:To investigate the biomechanical mechanism of different orthopedic modalities for the treatment of adolescent idiopathic scoliosis to provide a basis for clinical selection of treatment modalities based on the spine model of adolescent idiopathic scoliosis patients.METHODS:Based on the CT images of an adolescent idiopathic scoliosis patient,a scoliosis model(C7-L5)was reconstructed in Mimics software in three dimensions,and lateral thrust force was applied at the T8/T9 thorax and vertical distraction force was applied over the C7 vertebra with the magnitude of 20,40,60,80,100,and 120 N.The intervertebral disc stress and vertebral displacement in concave and convex sides,and Cobb angle of the spine were analyzed under two orthopedic modalities.RESULTS AND CONCLUSION:(1)With lateral thrust,there was no significant change in the C7T1-T7T8 intervertebral disc.The concave and convex stress of T7T8-L4L5 segment decreased first and then increased with the increase of lateral thrust force.The correction effect of lateral thrust on the segment near T8T9 was obvious and weakened with the extension of the segment to the cephalic and caudal ends.At 120 N of lateral thrust,the thoracic Cobb angle changed from 53.2° to 32.5° and the lumbar Cobb angle changed from 50.2° to 43.9°.(2)With the vertical distraction,the thoracic intervertebral disc stresses first decreased and then increased,and all the lumbar disc stresses decreased.The C7 displacement was the most obvious,and the correction effect gradually diminished with the segment extended to the caudal end.At a vertical distraction force of 120 N,the thoracic Cobb angle changed from 53.2° to 39.4° and the lumbar Cobb angle changed from 50.2° to 47.6°.(3)It is concluded that both orthopedic modalities provide improvement in the degree of scoliosis,with the thoracic correction being greater than the lumbar correction.Also,the asymmetric stress distribution on the concave and convex sides is improved,which contributes to normal bone growth.A vertical distraction approach is appropriate for larger Cobb angles,and a lateral thrust approach is appropriate for smaller Cobb angles.The results of this study help to understand the mechanism of spinal orthosis and provide a theoretical basis for the choice of orthopedic approach.

Objective:Papillary thyroid carcinoma with a maximum tumor diameter of ≤1 cm was defined as papillary thyroid carcinoma (PTC). To explore the clinical risk factors of central lymph node metastasis (CLNM) in PTC at different locations.Methods:The clinical and pathological data of 1383 cases with solitary PTC in Hangzhou First People’s Hospital were retrospectively analyzed, and they were divided into isthmus group (175 cases), near-isthmus group (95 cases) and lateral lobe group (1113 cases) according to their tumor location. Univariate and multivariate analyses were used to analyze the relationship between gender, age, tumor maximum diameter, Hashimoto’s thyroiditis (HT) and CLNM, and the threshold for the occurrence of CLNM in each group of age and tumor maximum diameter was determined by the area under the receiver operating characteristic (ROC) .Results:The proportion of CLNM in the isthmus group, near-isthmus group and the lateral lobe group were 39.4% (69/175), 35.8% (34/95) and 29.6% (329/1113), respectively ( χ2=7.84, P=0.020). The intra-group comparison showed that there were statistical differences between the isthmus group and the lateral lobe group ( χ2=6.90, P=0.011), and there were no statistical differences between the isthmus group and near-isthmus group ( χ2=0.35, P=0.601), and near-isthmus group and the lateral leaf group ( χ2=1.62, P=0.313). Univariate and multivariate analysis showed that male ( OR: 3.697) and age < 38.5 years ( OR: 4.727) were independent risk factors for CLNM in PTC in the Isthmus Group, while male ( OR: 2.193), without HT ( OR: 1.702), tumor maximum diameter > 6.5 mm ( OR: 2.535) and age < 45.5 years ( OR: 3.030) were independent risk factors for CLNM in PTC in the lateral lobe group. Conclusions:Male sex and age are independent risk factors for CLNM in isthmus and lateral lobe PTC, and uncomplicated HT and tumor maximum diameter are also independent risk factors for CLNM in lateral lobe PTC. The incidence of CLNM in PTC in the isthmus, near-isthmus and lateral lobes decreased sequentially, and PTC in the near isthmus can not be simply regarded as the isthmus or lateral lobe PTC, and the lymph nodes in the central area should be fully evaluated before surgery to provide individualized treatment.

Objective:Papillary thyroid carcinoma with a maximum tumor diameter of ≤1 cm was defined as papillary thyroid carcinoma (PTC). To explore the clinical risk factors of central lymph node metastasis (CLNM) in PTC at different locations.Methods:The clinical and pathological data of 1383 cases with solitary PTC in Hangzhou First People’s Hospital were retrospectively analyzed, and they were divided into isthmus group (175 cases), near-isthmus group (95 cases) and lateral lobe group (1113 cases) according to their tumor location. Univariate and multivariate analyses were used to analyze the relationship between gender, age, tumor maximum diameter, Hashimoto’s thyroiditis (HT) and CLNM, and the threshold for the occurrence of CLNM in each group of age and tumor maximum diameter was determined by the area under the receiver operating characteristic (ROC) .Results:The proportion of CLNM in the isthmus group, near-isthmus group and the lateral lobe group were 39.4% (69/175), 35.8% (34/95) and 29.6% (329/1113), respectively ( χ2=7.84, P=0.020). The intra-group comparison showed that there were statistical differences between the isthmus group and the lateral lobe group ( χ2=6.90, P=0.011), and there were no statistical differences between the isthmus group and near-isthmus group ( χ2=0.35, P=0.601), and near-isthmus group and the lateral leaf group ( χ2=1.62, P=0.313). Univariate and multivariate analysis showed that male ( OR: 3.697) and age < 38.5 years ( OR: 4.727) were independent risk factors for CLNM in PTC in the Isthmus Group, while male ( OR: 2.193), without HT ( OR: 1.702), tumor maximum diameter > 6.5 mm ( OR: 2.535) and age < 45.5 years ( OR: 3.030) were independent risk factors for CLNM in PTC in the lateral lobe group. Conclusions:Male sex and age are independent risk factors for CLNM in isthmus and lateral lobe PTC, and uncomplicated HT and tumor maximum diameter are also independent risk factors for CLNM in lateral lobe PTC. The incidence of CLNM in PTC in the isthmus, near-isthmus and lateral lobes decreased sequentially, and PTC in the near isthmus can not be simply regarded as the isthmus or lateral lobe PTC, and the lymph nodes in the central area should be fully evaluated before surgery to provide individualized treatment.

BACKGROUND:The asymmetrical biomechanical environment of adolescent idiopathic scoliosis can lead to further wedge deformation of the vertebral body,which may affect cardiopulmonary function and compress nerves in severe cases.Adolescent idiopathic scoliosis with different degrees of scoliosis should be treated with exercise,bracing,and surgery.However,the mechanical mechanism of selecting an orthopedic approach remains unclear due to the individual variability of patients.OBJECTIVE:To investigate the biomechanical mechanism of different orthopedic modalities for the treatment of adolescent idiopathic scoliosis to provide a basis for clinical selection of treatment modalities based on the spine model of adolescent idiopathic scoliosis patients.METHODS:Based on the CT images of an adolescent idiopathic scoliosis patient,a scoliosis model(C7-L5)was reconstructed in Mimics software in three dimensions,and lateral thrust force was applied at the T8/T9 thorax and vertical distraction force was applied over the C7 vertebra with the magnitude of 20,40,60,80,100,and 120 N.The intervertebral disc stress and vertebral displacement in concave and convex sides,and Cobb angle of the spine were analyzed under two orthopedic modalities.RESULTS AND CONCLUSION:(1)With lateral thrust,there was no significant change in the C7T1-T7T8 intervertebral disc.The concave and convex stress of T7T8-L4L5 segment decreased first and then increased with the increase of lateral thrust force.The correction effect of lateral thrust on the segment near T8T9 was obvious and weakened with the extension of the segment to the cephalic and caudal ends.At 120 N of lateral thrust,the thoracic Cobb angle changed from 53.2° to 32.5° and the lumbar Cobb angle changed from 50.2° to 43.9°.(2)With the vertical distraction,the thoracic intervertebral disc stresses first decreased and then increased,and all the lumbar disc stresses decreased.The C7 displacement was the most obvious,and the correction effect gradually diminished with the segment extended to the caudal end.At a vertical distraction force of 120 N,the thoracic Cobb angle changed from 53.2° to 39.4° and the lumbar Cobb angle changed from 50.2° to 47.6°.(3)It is concluded that both orthopedic modalities provide improvement in the degree of scoliosis,with the thoracic correction being greater than the lumbar correction.Also,the asymmetric stress distribution on the concave and convex sides is improved,which contributes to normal bone growth.A vertical distraction approach is appropriate for larger Cobb angles,and a lateral thrust approach is appropriate for smaller Cobb angles.The results of this study help to understand the mechanism of spinal orthosis and provide a theoretical basis for the choice of orthopedic approach.

BACKGROUND:Ankylosing spondylitis is a chronic inflammatory disease with chronic rheumatic immunity.Soft tissue ossification and fusion and spinal stiffness can cause biomechanical changes. OBJECTIVE:To reconstruct the lumbar-sacral intervertebral disc in ankylosing spondylitis patients with lumbar kyphosis by finite element analysis,and to study the range of motion of each segment of T11-S1 and the biomechanical characteristics of annulus fibrosus and nucleus pulposus. METHODS:The imaging data were obtained from an ankylosing spondylitis patient with lumbar kyphosis.The original CT image data of continuously scanned spine were imported into Mimics 21.0 in DICOM format,and T11-S1 was reconstructed respectively.The established model was imported into 3-Matic software in the format of"Stl"to reconstruct the intervertebral disc,and the fibrous intervertebral disc model was obtained.The improved model was further imported into Hypermesh software,and the vertebra,nucleus pulposus,annulus fibrosus and ligament were mesh-divided.After the material properties were given,the model was imported into ABAQUS software to observe the range of motion of each vertebral body in seven different working conditions of T11-S1,and analyze the biomechanical characteristics of each segment of annulus fibrosus and nucleus pulposus. RESULTS AND CONCLUSION:(1)The range of motion of L1 vertebrae was higher than that of other vertebrae under six different working conditions:extension,forward flexion,rotation(left and right),and lateral flexion(left and right).The maximum range of motion was 2.18° during L1 vertebral flexion,and the minimum range of motion was 0.12° during L5 vertebral extension.(2)The annular fiber flexion at L2-L3 segments was greater than the extension(P<0.05),and the annular fiber flexion at L3-L4 and L4-L5 segments was less than the extension(P<0.05).The left rotation of L1-L2 annular fibers was greater than the right rotation(P<0.05).The left flexion of the annulus was greater than the right flexion in L1-L2,L2-L3,L3-L4,L4-L5 and L5-S1 segments(P<0.05).(3)The nucleus pulposus stresses of T11-L12,L1-L2,L2-L3,L3-L4 and L4-L5 segments in forward flexion were greater than in extension(P<0.05).The left rotation of T12-L1 and L3-L4 segments was smaller than the right rotation(P<0.05),and that of T11-T12,L1-L2,and L2-L3 segments was larger than the right rotation(P<0.05).The left flexion was larger than the right flexion in the T11-S1 segment.(4)It is concluded that in ankylosing spondylitis patients with lumbar kyphosis,the minimum range of motion of the vertebral body is located at the L5 vertebral body in extension.To prevent fractures,it is recommended to avoid exercise in the extension position.During the onset of lumbar kyphosis in patients with ankylosing spondylitis,the maximum stress of the annulus fibrosus and nucleus pulposus is located in the L1-L2 segment,which is fixed and will not alter with the change of body position.The late surgical treatment and correction of deformity should focus on releasing the pressure of the annulus fibrosus and nucleus pulposus in this segment to avoid the rupture of the annulus fibrosus and the injury of the nucleus pulposus.

BACKGROUND:Ankylosing spondylitis is a progressive inflammation of spinal stiffness deformity caused by tissue ossification and fibrosis.The posture of ankylosing spondylitis patients is abnormal and their activities are limited that minor injuries can lead to thoracolumbar fractures.Traditional medical image observation limits doctors'preoperative decision planning and postoperative disease prevention for ankylosing spondylitis treatment. OBJECTIVE:Based on the spinal model of ankylosing spondylitis patients before and after posterior spinal cancellous ossification osteotomy("Y"osteotomy for short),to explore the biomechanical changes of"Y"osteotomy and fixation in the treatment of ankylosing spondylitis. METHODS:Based on the preoperative and postoperative CT images of an ankylosing spondylitis patient who went to the Second Affiliated Hospital of Inner Mongolia Medical University,a three-dimensional spine model(T11-S1)before and after"Y"osteotomy(L3 osteotomy)was reconstructed in Mimics 19.0 software.A 7.5 Nm torque was applied to the top of T11 vertebral body to simulate the movement of the spine under six conditions:flexion,extension,left bending,right bending,left rotation and right rotation.Finally,the range of motion of each vertebral body,the stress of each intervertebral disc,and the stress of the screw rod system were simulated. RESULTS AND CONCLUSION:(1)After"Y"type osteotomy and posterior fixation,the range of motion of all vertebrae in the spine decreased,and the loss rate of upper vertebrae was large(L1:77.95%).(2)The maximum stress of the spinal intervertebral disc before operation occurred at the L1-L2 segment(0.55 MPa),and the maximum stress of the spinal intervertebral disc after operation occurred at the T11-T12 segment(0.50 MPa),and the stress of intervertebral disc below T12 was far less than that before operation.(3)The maximum stress of the screw rod system(166.67 MPa)occurred in the upper and middle segments of the rod body and the root of the pedicle screw.(4)In conclusion,the"Y"type posterior fixation operation enhances the stability of the spine and reduces the range of motion of the spine.The vertebral body decompression of the fixed segment is great and the stress-shielding phenomenon of the lower vertebral body is significant.The stiffness of the rod body and the stress concentration area of the pedicle screw should be strengthened to avoid the fracture of the rod caused by stress fatigue.