Previous studies of animal models of chronic mechanical compression of the spinal cord have mainly focused on cervical and thoracic lesions, but few studies have investigated thoracolumbar injury. The specific pathoph...Previous studies of animal models of chronic mechanical compression of the spinal cord have mainly focused on cervical and thoracic lesions, but few studies have investigated thoracolumbar injury. The specific pathophysiological mechanism of chronic thoracolumbar cord injury has not yet been elucidated. The purpose of this study was to improve animal models of chronic thoracolumbar cord compression using the progressive screw. A custom-designed flat plastic screw was implanted in the spinal cord between thoracic vertebrae 12 and lumbar 1 of rats. The screw was tightened one complete turn（0.5 mm） every 7 days for 4 weeks to create different levels of chronic spinal cord compression. Following insertion of the screw, there was a significant decline in motor function of the hind limbs, and severe stenosis of micro-computed tomography parameters in the spinal cord. Cortical somatosensory evoked potential amplitudes were reduced remarkably, and latencies were prolonged at 30 minutes after surgery. The loss of motor neurons in the gray matter was marked. Demyelination and cavitation were observed in the white matter. An appropriate rat model of chronic thoracolumbar cord compression was successfully created using the progressive screw compression method, which simulated spinal cord compression injury.展开更多
Background:Available research about the anatomic patterns of intertrochanteric fractures is lacking,and fracture mapping has not previously been performed on intertrochanteric fractures.This study aimed to determine t...Background:Available research about the anatomic patterns of intertrochanteric fractures is lacking,and fracture mapping has not previously been performed on intertrochanteric fractures.This study aimed to determine the major trajectories of intertrochanteric fracture lines using computed tomography data from a series of surgically treated patients.Methods:In this study,504 patients with intertrochanteric fractures were retrospectively analyzed.Fracture patterns were graded according to Arbeitsgemeinschaft für Osteosynthesefragen(AO)classification.Fracture lines were transcribed onto proximal femoral templates and graphically superimposed to create a compilation of fracture maps that were subsequently divided into anterior,posterior,lateral,and medial fracture maps to create a three-dimensional(3D)pattern by reducing fragments in the 3D models.The fracture maps were then converted into frequency spectra.The major fracture patterns were assessed by focusing on the lateral femoral wall,lesser trochanter,intertrochanteric crest,and inner cortical buttress.Results:Anterior,posterior,lateral,and medial fracture maps were created.The majority of fracture lines(85.9%,433/504)on the anterior maps were along the intertrochanteric line where the iliofemoral ligament was attached.In the medial plane,the majority of fracture lines(49.0%,247/504)shown on the frequency spectrum included the turning point involving the third quadrant.In the posterior plane,the majority of fracture lines(52.0%,262/504)involved the intertrochanteric crest from the greater to the lesser trochanter.In the lateral plane,the majority of fracture lines(62.7%,316/504)involved the greater trochanter at the gluteus medius attachment.Conclusions:The fracture patterns observed in the present study might be used to describe morphologic characteristics and aid with management strategies.Further classifications or modifications that incorporate the fracture patterns identified in this study may be used in future research.展开更多
基金supported by the Military Medical Research Foundation of China,No.06MA283
文摘Previous studies of animal models of chronic mechanical compression of the spinal cord have mainly focused on cervical and thoracic lesions, but few studies have investigated thoracolumbar injury. The specific pathophysiological mechanism of chronic thoracolumbar cord injury has not yet been elucidated. The purpose of this study was to improve animal models of chronic thoracolumbar cord compression using the progressive screw. A custom-designed flat plastic screw was implanted in the spinal cord between thoracic vertebrae 12 and lumbar 1 of rats. The screw was tightened one complete turn（0.5 mm） every 7 days for 4 weeks to create different levels of chronic spinal cord compression. Following insertion of the screw, there was a significant decline in motor function of the hind limbs, and severe stenosis of micro-computed tomography parameters in the spinal cord. Cortical somatosensory evoked potential amplitudes were reduced remarkably, and latencies were prolonged at 30 minutes after surgery. The loss of motor neurons in the gray matter was marked. Demyelination and cavitation were observed in the white matter. An appropriate rat model of chronic thoracolumbar cord compression was successfully created using the progressive screw compression method, which simulated spinal cord compression injury.
文摘Background:Available research about the anatomic patterns of intertrochanteric fractures is lacking,and fracture mapping has not previously been performed on intertrochanteric fractures.This study aimed to determine the major trajectories of intertrochanteric fracture lines using computed tomography data from a series of surgically treated patients.Methods:In this study,504 patients with intertrochanteric fractures were retrospectively analyzed.Fracture patterns were graded according to Arbeitsgemeinschaft für Osteosynthesefragen(AO)classification.Fracture lines were transcribed onto proximal femoral templates and graphically superimposed to create a compilation of fracture maps that were subsequently divided into anterior,posterior,lateral,and medial fracture maps to create a three-dimensional(3D)pattern by reducing fragments in the 3D models.The fracture maps were then converted into frequency spectra.The major fracture patterns were assessed by focusing on the lateral femoral wall,lesser trochanter,intertrochanteric crest,and inner cortical buttress.Results:Anterior,posterior,lateral,and medial fracture maps were created.The majority of fracture lines(85.9%,433/504)on the anterior maps were along the intertrochanteric line where the iliofemoral ligament was attached.In the medial plane,the majority of fracture lines(49.0%,247/504)shown on the frequency spectrum included the turning point involving the third quadrant.In the posterior plane,the majority of fracture lines(52.0%,262/504)involved the intertrochanteric crest from the greater to the lesser trochanter.In the lateral plane,the majority of fracture lines(62.7%,316/504)involved the greater trochanter at the gluteus medius attachment.Conclusions:The fracture patterns observed in the present study might be used to describe morphologic characteristics and aid with management strategies.Further classifications or modifications that incorporate the fracture patterns identified in this study may be used in future research.
