Objective. To investigate the biomechanical aspects of etiology,pathology, clinical manifestation, diagnosis and surgical treatment of the lumbar spinal stenosis. Methods’ A series of biomechanical methods, such as t...Objective. To investigate the biomechanical aspects of etiology,pathology, clinical manifestation, diagnosis and surgical treatment of the lumbar spinal stenosis. Methods’ A series of biomechanical methods, such as three-dimensional finite element models. three-dimensional kinematic measurement, cadeveric evaluation, and imaging assessment was applied to correlate lumbar biomechanics and lumbar spinal stenosis. Surgery of lumbar spinal stenosis has been improved. Results. The stresses significantly concentrate on the posterolateral part of the annulus fibrosus of disc, the posterior surface of vertebral body, the pedicle, the interarticularis and the facet joints. This trend is intensified by disc degeneration and lumbar backward extension. Posterior element resection has a definite effect upon the biomechanical behavior of lumbar vertebrae. The improved operations proved satis- factory. Conclusion. Stress concentration in the lumbar vertebrae is of importance to the etiology of degenerative lumbar spinal stenosis, and disc degeneration is the initial key of this process. Then these will be aggravated by backward extension. Functional radiography and myelography are of assistance to the diagnosis o f the lumbar spinal stenosis. For the surgical treatment of the lumbar spinal stenosis, destruction of the posterior element should be avoid as far as possible based upon the thorough decompression. Maintaining the lumbar spine in flexion by fusion after decompression has been proved a useful method. When developmental spinal stenosis is combined with disc herniation, discectomy through laminotomy is recommend for decompression.展开更多
The majority of foot deformities are related to arch collapse or instability,especially the longitudinal arch.Although the relationship between the plantar fascia and arch height has been previously investigated,the s...The majority of foot deformities are related to arch collapse or instability,especially the longitudinal arch.Although the relationship between the plantar fascia and arch height has been previously investigated,the stress distribution remains unclear.The aim of this study was to explore the role of the plantar ligaments in foot arch biomechanics.We constructed a geometrical detailed three-dimensional (3-D) finite element (FE) model of the human foot and ankle from computer tomography images.The model comprised the majority of joints in the foot as well as bone segments,major ligaments,and plantar soft tissue.Release of the plantar fascia and other ligaments was simulated to evaluate the corresponding biomechanical effects on load distribution of the bony and ligamentous structures.These intrinsic ligaments of the foot arch were sectioned to simulate different pathologic situations of injury to the plantar ligaments,and to explore bone segment displacement and stress distribution.The validity of the 3-D FE model was verified by comparing results with experimentally measured data via the displacement and von Mise stress of each bone segment.Plantar fascia release decreased arch height,but did not cause total collapse of the foot arch.The longitudinal foot arch was lost when all the four major plantar ligaments were sectioned simultaneously.Plantar fascia release was compromised by increased strain applied to the plantar ligaments and intensified stress in the midfoot and metatarsal bones.Load redistribution among the centralized metatarsal bones and focal stress relief at the calcaneal insertion were predicted.The 3-D FE model indicated that plantar fascia release may provide relief of focal stress and associated heel pain.However,these operative procedures may pose a risk to arch stability and clinically may produce dorsolateral midfoot pain.The initial strategy for treating plantar fasciitis should be non-operative.展开更多
基金This project was supported by the National Natural ScienceFoundation of China.
文摘Objective. To investigate the biomechanical aspects of etiology,pathology, clinical manifestation, diagnosis and surgical treatment of the lumbar spinal stenosis. Methods’ A series of biomechanical methods, such as three-dimensional finite element models. three-dimensional kinematic measurement, cadeveric evaluation, and imaging assessment was applied to correlate lumbar biomechanics and lumbar spinal stenosis. Surgery of lumbar spinal stenosis has been improved. Results. The stresses significantly concentrate on the posterolateral part of the annulus fibrosus of disc, the posterior surface of vertebral body, the pedicle, the interarticularis and the facet joints. This trend is intensified by disc degeneration and lumbar backward extension. Posterior element resection has a definite effect upon the biomechanical behavior of lumbar vertebrae. The improved operations proved satis- factory. Conclusion. Stress concentration in the lumbar vertebrae is of importance to the etiology of degenerative lumbar spinal stenosis, and disc degeneration is the initial key of this process. Then these will be aggravated by backward extension. Functional radiography and myelography are of assistance to the diagnosis o f the lumbar spinal stenosis. For the surgical treatment of the lumbar spinal stenosis, destruction of the posterior element should be avoid as far as possible based upon the thorough decompression. Maintaining the lumbar spine in flexion by fusion after decompression has been proved a useful method. When developmental spinal stenosis is combined with disc herniation, discectomy through laminotomy is recommend for decompression.
基金supported by the National Natural Science Foundation of China(Grant No. 30801163)
文摘The majority of foot deformities are related to arch collapse or instability,especially the longitudinal arch.Although the relationship between the plantar fascia and arch height has been previously investigated,the stress distribution remains unclear.The aim of this study was to explore the role of the plantar ligaments in foot arch biomechanics.We constructed a geometrical detailed three-dimensional (3-D) finite element (FE) model of the human foot and ankle from computer tomography images.The model comprised the majority of joints in the foot as well as bone segments,major ligaments,and plantar soft tissue.Release of the plantar fascia and other ligaments was simulated to evaluate the corresponding biomechanical effects on load distribution of the bony and ligamentous structures.These intrinsic ligaments of the foot arch were sectioned to simulate different pathologic situations of injury to the plantar ligaments,and to explore bone segment displacement and stress distribution.The validity of the 3-D FE model was verified by comparing results with experimentally measured data via the displacement and von Mise stress of each bone segment.Plantar fascia release decreased arch height,but did not cause total collapse of the foot arch.The longitudinal foot arch was lost when all the four major plantar ligaments were sectioned simultaneously.Plantar fascia release was compromised by increased strain applied to the plantar ligaments and intensified stress in the midfoot and metatarsal bones.Load redistribution among the centralized metatarsal bones and focal stress relief at the calcaneal insertion were predicted.The 3-D FE model indicated that plantar fascia release may provide relief of focal stress and associated heel pain.However,these operative procedures may pose a risk to arch stability and clinically may produce dorsolateral midfoot pain.The initial strategy for treating plantar fasciitis should be non-operative.
