ABSTRACT
Objective To investigate the role and influence of physiological loading and overloading on microgravity-induced osteoporosis,so as to find a reliable way to prevent or treat related-orthopedic disorders in astronauts induced by long-time space activity.Metbods The microgravity environment in space was simulated by tail-suspension experiment,then the osteoporosis models of mice were built.A total of 32 C57BL/6J mice were randomly and evenly separated into four groups:normal group (normal),tail-suspension group (TS),physiological loading group (loading) and overloading group (overloading).Periodic dynamic mechanical load was applied on the left tibia in loading group and overloading group during tail-suspension test.After four weeks,tibial mechanical properties,micro-parameters of bone trabecular,biochemical indices and osteogenesis-related gene expression in each group were compared and analyzed.Results A great loss of tibial cancellous bone,significantly lower tibial biomechanical expression,serious damage of microstructure and weaker osteogenic activity were found in tail-suspended mice as compared with those of normal group.Physiological loading could clearly improve mechanical properties of bones,microstructure of bone trabecular,osteogenic activity and relative gene expression (P ＜ 0.05).Overloading could also improve the condition of microgravity-induced osteoporosis,but the effect was not obvious (P ＞ 0.05).Conclusions Tail-suspension can successfully simulate microgravity environment and duplicate osteoporosis model.Physiological loading can effectively prevent the emergence and development of microgravity-induced osteoporosis,while overloading can also counter microgravity-induced osteoporosis,but the results have no significant differences.
ABSTRACT
Objective To investigate the structure and biomechanical property differences in different regions of the femoral head for elderly patients with femoral neck fractures,and to study its influence on internal fixation for fracture.Methods Twenty femoral head specimens were collected from elderly patients with femoral neck fracture after joint replacement.The femoral head was divided into 3 parts (lateral,inferior and medial region) with reference to anatomical markers on surface of the femoral head.After the position and drilling direction of the ring drill were determined,a circular drill was used to obtain the cylindrical cancellous bone columns with 10 mm in diameter and 10 mm in height.The data of cancellous bone columns in different regions were analyzed by Micro-CT scanning system,including bone volume fraction (BVF),trabecular space (Tb.Sp),trabecular thickness (Tb.Th),the number of trabecular number (Tb.N),the bone surface volume ratio (bone surface/bone volume,BS/BV),structural model index (SMI).Mechanical property differences of bone tissues in different regions were calculated by micro-finite element analysis.Results Bone mass in the elderly osteoporotic femoral head decreased,and there were significant differences in bone microstructure and mechanical properties in different regions of the femoral head.Bone microstructure and mechanical properties in medial region were obviously superior to those in lateral and interior region.Conclusions The bone structure and mechanical strength in medial region of the femoral head are obvious superior to those in lateral and inferior regions.The position for internal fixation should be fully considered during treatment of osteoporotic femoral neck fracture in clinic.
ABSTRACT
Objective To investigate the role and influence of physiological loading and overloading on microgravity-induced osteoporosis,so as to find a reliable way to prevent or treat related-orthopedic disorders in astronauts induced by long-time space activity.Metbods The microgravity environment in space was simulated by tail-suspension experiment,then the osteoporosis models of mice were built.A total of 32 C57BL/6J mice were randomly and evenly separated into four groups:normal group (normal),tail-suspension group (TS),physiological loading group (loading) and overloading group (overloading).Periodic dynamic mechanical load was applied on the left tibia in loading group and overloading group during tail-suspension test.After four weeks,tibial mechanical properties,micro-parameters of bone trabecular,biochemical indices and osteogenesis-related gene expression in each group were compared and analyzed.Results A great loss of tibial cancellous bone,significantly lower tibial biomechanical expression,serious damage of microstructure and weaker osteogenic activity were found in tail-suspended mice as compared with those of normal group.Physiological loading could clearly improve mechanical properties of bones,microstructure of bone trabecular,osteogenic activity and relative gene expression (P ＜ 0.05).Overloading could also improve the condition of microgravity-induced osteoporosis,but the effect was not obvious (P ＞ 0.05).Conclusions Tail-suspension can successfully simulate microgravity environment and duplicate osteoporosis model.Physiological loading can effectively prevent the emergence and development of microgravity-induced osteoporosis,while overloading can also counter microgravity-induced osteoporosis,but the results have no significant differences.
ABSTRACT
Objective To investigate the structure and biomechanical property differences in different regions of the femoral head for elderly patients with femoral neck fractures,and to study its influence on internal fixation for fracture.Methods Twenty femoral head specimens were collected from elderly patients with femoral neck fracture after joint replacement.The femoral head was divided into 3 parts (lateral,inferior and medial region) with reference to anatomical markers on surface of the femoral head.After the position and drilling direction of the ring drill were determined,a circular drill was used to obtain the cylindrical cancellous bone columns with 10 mm in diameter and 10 mm in height.The data of cancellous bone columns in different regions were analyzed by Micro-CT scanning system,including bone volume fraction (BVF),trabecular space (Tb.Sp),trabecular thickness (Tb.Th),the number of trabecular number (Tb.N),the bone surface volume ratio (bone surface/bone volume,BS/BV),structural model index (SMI).Mechanical property differences of bone tissues in different regions were calculated by micro-finite element analysis.Results Bone mass in the elderly osteoporotic femoral head decreased,and there were significant differences in bone microstructure and mechanical properties in different regions of the femoral head.Bone microstructure and mechanical properties in medial region were obviously superior to those in lateral and interior region.Conclusions The bone structure and mechanical strength in medial region of the femoral head are obvious superior to those in lateral and inferior regions.The position for internal fixation should be fully considered during treatment of osteoporotic femoral neck fracture in clinic.
ABSTRACT
Objective To investigate the role and influence of physiological loading and overloading on microgravity-induced osteoporosis, so as to find a reliable way to prevent or treat related-orthopedic disorders in astronauts induced by long-time space activity. Methods The microgravity environment in space was simulated by tail-suspension experiment, then the osteoporosis models of mice were built. A total of 32 C57BL/6J mice were randomly and evenly separated into four groups: normal group (normal), tail-suspension group (TS), physiological loading group (loading) and overloading group (overloading). Periodic dynamic mechanical load was applied on the left tibia in loading group and overloading group during tail-suspension test. After four weeks, tibial mechanical properties, micro-parameters of bone trabecular, biochemical indices and osteogenesis-related gene expression in each group were compared and analyzed. Results A great loss of tibial cancellous bone, significantly lower tibial biomechanical expression, serious damage of microstructure and weaker osteogenic activity were found in tail-suspended mice as compared with those of normal group. Physiological loading could clearly improve mechanical properties of bones, microstructure of bone trabecular, osteogenic activity and relative gene expression (P＜0.05). Overloading could also improve the condition of microgravity-induced osteoporosis, but the effect was not obvious (P＞0.05). Conclusions Tail-suspension can successfully simulate microgravity environment and duplicate osteoporosis model. Physiological loading can effectively prevent the emergence and development of microgravity-induced osteoporosis, while overloading can also counter microgravity-induced osteoporosis, but the results have no significant differences.
ABSTRACT
Objective To investigate the structure and biomechanical property differences in different regions of the femoral head for elderly patients with femoral neck fractures, and to study its influence on internal fixation for fracture. Methods Twenty femoral head specimens were collected from elderly patients with femoral neck fracture after joint replacement. The femoral head was divided into 3 parts (lateral, inferior and medial region) with reference to anatomical markers on surface of the femoral head. After the position and drilling direction of the ring drill were determined, a circular drill was used to obtain the cylindrical cancellous bone columns with 10 mm in diameter and 10 mm in height. The data of cancellous bone columns in different regions were analyzed by Micro-CT scanning system, including bone volume fraction (BVF), trabecular space (Tb.Sp), trabecular thickness (Tb.Th), the number of trabecular number (Tb.N), the bone surface volume ratio (bone surface/bone volume, BS/BV), structural model index (SMI). Mechanical property differences of bone tissues in different regions were calculated by micro-finite element analysis. ResultsBone mass in the elderly osteoporotic femoral head decreased, and there were significant differences in bone microstructure and mechanical properties in different regions of the femoral head. Bone microstructure and mechanical properties in medial region were obviously superior to those in lateral and interior region. Conclusions The bone structure and mechanical strength in medial region of the femoral head are obvious superior to those in lateral and inferior regions. The position for internal fixation should be fully considered during treatment of osteoporotic femoral neck fracture in clinic.
ABSTRACT
Objective To investigate the role and influence of physiological loading and overloading on microgravity-induced osteoporosis,so as to find a reliable way to prevent or treat related-orthopedic disorders in astronauts induced by long-time space activity.Metbods The microgravity environment in space was simulated by tail-suspension experiment,then the osteoporosis models of mice were built.A total of 32 C57BL/6J mice were randomly and evenly separated into four groups:normal group (normal),tail-suspension group (TS),physiological loading group (loading) and overloading group (overloading).Periodic dynamic mechanical load was applied on the left tibia in loading group and overloading group during tail-suspension test.After four weeks,tibial mechanical properties,micro-parameters of bone trabecular,biochemical indices and osteogenesis-related gene expression in each group were compared and analyzed.Results A great loss of tibial cancellous bone,significantly lower tibial biomechanical expression,serious damage of microstructure and weaker osteogenic activity were found in tail-suspended mice as compared with those of normal group.Physiological loading could clearly improve mechanical properties of bones,microstructure of bone trabecular,osteogenic activity and relative gene expression (P ＜ 0.05).Overloading could also improve the condition of microgravity-induced osteoporosis,but the effect was not obvious (P ＞ 0.05).Conclusions Tail-suspension can successfully simulate microgravity environment and duplicate osteoporosis model.Physiological loading can effectively prevent the emergence and development of microgravity-induced osteoporosis,while overloading can also counter microgravity-induced osteoporosis,but the results have no significant differences.
ABSTRACT
Objective To investigate the structure and biomechanical property differences in different regions of the femoral head for elderly patients with femoral neck fractures,and to study its influence on internal fixation for fracture.Methods Twenty femoral head specimens were collected from elderly patients with femoral neck fracture after joint replacement.The femoral head was divided into 3 parts (lateral,inferior and medial region) with reference to anatomical markers on surface of the femoral head.After the position and drilling direction of the ring drill were determined,a circular drill was used to obtain the cylindrical cancellous bone columns with 10 mm in diameter and 10 mm in height.The data of cancellous bone columns in different regions were analyzed by Micro-CT scanning system,including bone volume fraction (BVF),trabecular space (Tb.Sp),trabecular thickness (Tb.Th),the number of trabecular number (Tb.N),the bone surface volume ratio (bone surface/bone volume,BS/BV),structural model index (SMI).Mechanical property differences of bone tissues in different regions were calculated by micro-finite element analysis.Results Bone mass in the elderly osteoporotic femoral head decreased,and there were significant differences in bone microstructure and mechanical properties in different regions of the femoral head.Bone microstructure and mechanical properties in medial region were obviously superior to those in lateral and interior region.Conclusions The bone structure and mechanical strength in medial region of the femoral head are obvious superior to those in lateral and inferior regions.The position for internal fixation should be fully considered during treatment of osteoporotic femoral neck fracture in clinic.
ABSTRACT
Transient osteoporosis of hip (TOH) is a spontaneous resolving skeletal disorder characterized by sudden onset of severe pain which resolves within 6-12 months. It is seen more commonly in middle aged men, though also seen in 3rd trimester of pregnancy. MRI is the main diagnostic tool. It is idiopathic in nature. We present a case report of a young adult male who presented with migratory transient osteoporosis of both hip joints separated by a period of around 11/2 years. He was managed conservatively and recovered completely both times.
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Objective To study the method of percutaneous vertebroplasty (PVP) and investigate its clinical efficacy. Methods Tweenty five cases (13 patients with painful osteoporotic vertebral fractures, 8 cases with metastatic neoplasms and 4 cases with hemangionmas) were treated by the injection of polymethyl methacrykate (PMMA) under DSA fluoroscopic guidance. the time of follow up ranged from 1 15 months. Results The procedure was successful in all patients. Among 25 patients, 18 experinced with complete relief of pain, 6 with conspicuous relief, 1 with no significant change. Two patients showed transient symptom of radiculopathy and no clinical complication in others. Conclusions PVP is a safe and feasible treatment for patients with hemangiomas and vertebral fractures caused by malignancies and osteoporosis.