Medial tibial stress syndrome(MTSS) is a debilitating overuse injury of the tibia sustained by individuals whoperform recurrent impact exercise such as athletes and military recruits. Characterised by diffuse tibial a...Medial tibial stress syndrome(MTSS) is a debilitating overuse injury of the tibia sustained by individuals whoperform recurrent impact exercise such as athletes and military recruits. Characterised by diffuse tibial anteromedial or posteromedial surface subcutaneous periostitis, in most cases it is also an injury involving underlying cortical bone microtrauma, although it is not clear if the soft tissue or cortical bone reaction occurs first. Nuclear bone scans and magnetic resonance imaging(MRI) can both be used for the diagnosis of MTSS, but the patient's history and clinical symptoms need to be considered in conjunction with the imaging findings for a correct interpretation of the results, as both imaging modalities have demonstrated positive findings in the absence of injury. However, MRI is rapidly becoming the preferred imaging modality for the diagnosis of bone stress injuries. It can also be used for the early diagnosis of MTSS, as the developing periosteal oedema can be identified. Retrospective studies have demonstrated that MTSS patients have lower bone mineral density(BMD) at the injury site than exercising controls, and preliminary data indicates the BMD is lower in MTSS subjects than tibial stress fracture(TSF) subjects. The values of a number of tibial geometric parameters such as cross-sectional area and section modulus are also lower in MTSS subjects than exercising controls, but not as low as the values in TSF subjects. Thus, the balance between BMD and cortical bone geometry may predict an individual's likelihood of developing MTSS. However, prospective longitudinal studies are needed to determine how these factors alter during the development of the injury and to find the detailed structural cause, which is still unknown. Finite element analysis has recently been used to examine the mechanisms involved in tibial stress injuries and offer a promising future tool to understand the mechanisms involved in MTSS. Contemporary accurate diagnosis of either MTSS or a TSF includes a thorough clinical ex展开更多
Background The association of long-term bisphosphonate treatment for osteoporosis and related safety problems such as atypical fractures were not clearly defined. This study was to evaluate the structural, densitometr...Background The association of long-term bisphosphonate treatment for osteoporosis and related safety problems such as atypical fractures were not clearly defined. This study was to evaluate the structural, densitometric and biomechanical properties of the prolonged bisphosphonate-loaded bones. Methods Bone mineral density （BMD） at hip and femoral midshaft, bone cross-sectional area, moment of inertia of both femurs, bone formation and resorption biochemical markers were compared between 28 elderly with at least 4 years of bisphosphonate treatment from 2002 through 2006 and age-matched group of 37 elderly. Results The total hip BMD and t-score were found not different between two groups. However, bisphosphonate treated patients were found to have significantly lower bone mineral content in the femoral shaft （P 〈0.05）; morphological study showed lower cross-sectional area in subtrochanteric and mid-diaphyseal region and thus significantly lower moment of inertia （P 〈0.01）. High resolution-peripheral quantitative computed tomography showed significantly decreased trabeculardensity, bone volume ratio, trabecular number but increased trabecular spacing in tibia and distal radius. Finite element analysis further confirmed significantly lower stiffness and failure load in tibia. Biochemical studies also showed lower bone resorption and severely suppressed bone formation activity （P 〈0.001）. Conclusions The unchanged total hip BMD between two groups confirmed the beneficial effects of bisphosphonate on trabecular bone, thus preventing osteoporotic fractures at large in previous studies. However, the inferior structural, densitometric and biomechanical properties at cortical bones, especially femur midshaft, need a special attention to look into the association between long-term bisphosphonate intake and the occurrence of stress fractures. When patients taking bisphosphonate complain of proximal thigh pain or discomfort, plain X-ray film can be the first line screening. All patients prescribed with b展开更多
目的 探讨伤后腕关节正位X线影像测量桡骨远端骨皮质厚度的可行性、桡骨远端骨皮质厚度与髋部及腰椎骨密度之间的关系以及评估桡骨远端骨皮质厚度预测骨质疏松症的能力。方法 对91例年龄≥50岁经X线确诊为桡骨远端骨折的患者行双能X线...目的 探讨伤后腕关节正位X线影像测量桡骨远端骨皮质厚度的可行性、桡骨远端骨皮质厚度与髋部及腰椎骨密度之间的关系以及评估桡骨远端骨皮质厚度预测骨质疏松症的能力。方法 对91例年龄≥50岁经X线确诊为桡骨远端骨折的患者行双能X线吸收检测法(dual energy X-ray absorptiometry,DXA)测定,根据 T 值分为两组:骨质疏松组55例,男性6例,女性49例,年龄52~83(63.5±8.2)岁,体质量 46~ 88(57.2±8.1)kg,体质量指数(body mass index,BMI)(24.3±3.0)kg/m^2;非骨质疏松组36例,男性2例,女性34例,年龄50~69(57.9±6.1)岁,体质量42.5~80.0(62.5±8.7)kg, BMI(25.5±3.3)kg/m^2。通过医学影像信息系统(picture archiving and communication systems,PACS),在腕关节正位X线影像上,于距离尺骨远端关节面40、60 mm处测量桡骨远端双侧骨皮质厚度。结果 骨质疏松组患者较非骨质疏松组年龄大、体质量轻,且桡骨远端骨皮质厚度较非骨质疏松组薄,骨皮质比率较非骨质疏松组低,差异有统计学意义( P <0.01);两组患者BMI差异无统计学意义( P >0.01)。桡骨远端骨皮质厚度与髋部骨密度正相关( r = 0.309, P =0.000),与腰椎骨密度正相关( r =0.445, P =0.000)。一元线性回归分析表明:桡骨远端骨皮质厚度每增加 1 mm ,髋部骨密度值增加0.071 g/cm^2( R^2=0.230, P =0.000),腰椎骨密度值增加0.065 g/cm^2 ( R^2= 0.265, P =0.000)。桡骨远端骨皮质厚度5.2 mm为诊断骨质疏松最佳诊断临界点,其敏感度80.4%、特异度69.4%、阴性预测值69.4%,曲线下面积为0.749。结论 桡骨远端骨皮质厚度与髋部及腰椎骨密度正相关,桡骨远端骨皮质变薄与骨质疏松相关,通过X线检查测量桡骨远端骨皮质厚度快速简便,可初步筛查骨量减少,并提示进一步行骨密度检查。展开更多
Objective To investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. Methods Orchiectomized and ovariectomized rat models are used to investigate sex hormone deficiency related ost...Objective To investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. Methods Orchiectomized and ovariectomized rat models are used to investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. A rat vertebral body can be longitudinally divided into central portion, which contain more trabecular bone, and para-endplate portions which contain more compact bone. In matured male and female Wistar and Sprague-Dawley rat lumbar spines, we investigated baseline bone mineral density （BMD） characteristics and the differential segmental responses in bone loss within the lumbar vertebral body post gonadal surgery with clinical multidetector computed tomography. Results Para-endplate sections had a higher BMD than central sections. The cephalad para-endplate sections had a higher BMD than the caudad para-endplate sections. Eight weeks after gonadal removal, there was more bone loss in central sections than para-endplate sections. The relative difference of bone loss between para-endplate and central sections was more apparent in male rats than in female rats. There was more bone loss in caudad sections than cephalad sections; this lead to a further increase of BMD difference between caudad para-endplate sections and cephalad para-endplate sections post gonadal surgery. Conclusion The approach described in this study provided a consistent way to study BMD change within predominantly compact bone portion and trabecular bone portion of the vertebral body.展开更多
文摘Medial tibial stress syndrome(MTSS) is a debilitating overuse injury of the tibia sustained by individuals whoperform recurrent impact exercise such as athletes and military recruits. Characterised by diffuse tibial anteromedial or posteromedial surface subcutaneous periostitis, in most cases it is also an injury involving underlying cortical bone microtrauma, although it is not clear if the soft tissue or cortical bone reaction occurs first. Nuclear bone scans and magnetic resonance imaging(MRI) can both be used for the diagnosis of MTSS, but the patient's history and clinical symptoms need to be considered in conjunction with the imaging findings for a correct interpretation of the results, as both imaging modalities have demonstrated positive findings in the absence of injury. However, MRI is rapidly becoming the preferred imaging modality for the diagnosis of bone stress injuries. It can also be used for the early diagnosis of MTSS, as the developing periosteal oedema can be identified. Retrospective studies have demonstrated that MTSS patients have lower bone mineral density(BMD) at the injury site than exercising controls, and preliminary data indicates the BMD is lower in MTSS subjects than tibial stress fracture(TSF) subjects. The values of a number of tibial geometric parameters such as cross-sectional area and section modulus are also lower in MTSS subjects than exercising controls, but not as low as the values in TSF subjects. Thus, the balance between BMD and cortical bone geometry may predict an individual's likelihood of developing MTSS. However, prospective longitudinal studies are needed to determine how these factors alter during the development of the injury and to find the detailed structural cause, which is still unknown. Finite element analysis has recently been used to examine the mechanisms involved in tibial stress injuries and offer a promising future tool to understand the mechanisms involved in MTSS. Contemporary accurate diagnosis of either MTSS or a TSF includes a thorough clinical ex
文摘Background The association of long-term bisphosphonate treatment for osteoporosis and related safety problems such as atypical fractures were not clearly defined. This study was to evaluate the structural, densitometric and biomechanical properties of the prolonged bisphosphonate-loaded bones. Methods Bone mineral density （BMD） at hip and femoral midshaft, bone cross-sectional area, moment of inertia of both femurs, bone formation and resorption biochemical markers were compared between 28 elderly with at least 4 years of bisphosphonate treatment from 2002 through 2006 and age-matched group of 37 elderly. Results The total hip BMD and t-score were found not different between two groups. However, bisphosphonate treated patients were found to have significantly lower bone mineral content in the femoral shaft （P 〈0.05）; morphological study showed lower cross-sectional area in subtrochanteric and mid-diaphyseal region and thus significantly lower moment of inertia （P 〈0.01）. High resolution-peripheral quantitative computed tomography showed significantly decreased trabeculardensity, bone volume ratio, trabecular number but increased trabecular spacing in tibia and distal radius. Finite element analysis further confirmed significantly lower stiffness and failure load in tibia. Biochemical studies also showed lower bone resorption and severely suppressed bone formation activity （P 〈0.001）. Conclusions The unchanged total hip BMD between two groups confirmed the beneficial effects of bisphosphonate on trabecular bone, thus preventing osteoporotic fractures at large in previous studies. However, the inferior structural, densitometric and biomechanical properties at cortical bones, especially femur midshaft, need a special attention to look into the association between long-term bisphosphonate intake and the occurrence of stress fractures. When patients taking bisphosphonate complain of proximal thigh pain or discomfort, plain X-ray film can be the first line screening. All patients prescribed with b
文摘目的 探讨伤后腕关节正位X线影像测量桡骨远端骨皮质厚度的可行性、桡骨远端骨皮质厚度与髋部及腰椎骨密度之间的关系以及评估桡骨远端骨皮质厚度预测骨质疏松症的能力。方法 对91例年龄≥50岁经X线确诊为桡骨远端骨折的患者行双能X线吸收检测法(dual energy X-ray absorptiometry,DXA)测定,根据 T 值分为两组:骨质疏松组55例,男性6例,女性49例,年龄52~83(63.5±8.2)岁,体质量 46~ 88(57.2±8.1)kg,体质量指数(body mass index,BMI)(24.3±3.0)kg/m^2;非骨质疏松组36例,男性2例,女性34例,年龄50~69(57.9±6.1)岁,体质量42.5~80.0(62.5±8.7)kg, BMI(25.5±3.3)kg/m^2。通过医学影像信息系统(picture archiving and communication systems,PACS),在腕关节正位X线影像上,于距离尺骨远端关节面40、60 mm处测量桡骨远端双侧骨皮质厚度。结果 骨质疏松组患者较非骨质疏松组年龄大、体质量轻,且桡骨远端骨皮质厚度较非骨质疏松组薄,骨皮质比率较非骨质疏松组低,差异有统计学意义( P <0.01);两组患者BMI差异无统计学意义( P >0.01)。桡骨远端骨皮质厚度与髋部骨密度正相关( r = 0.309, P =0.000),与腰椎骨密度正相关( r =0.445, P =0.000)。一元线性回归分析表明:桡骨远端骨皮质厚度每增加 1 mm ,髋部骨密度值增加0.071 g/cm^2( R^2=0.230, P =0.000),腰椎骨密度值增加0.065 g/cm^2 ( R^2= 0.265, P =0.000)。桡骨远端骨皮质厚度5.2 mm为诊断骨质疏松最佳诊断临界点,其敏感度80.4%、特异度69.4%、阴性预测值69.4%,曲线下面积为0.749。结论 桡骨远端骨皮质厚度与髋部及腰椎骨密度正相关,桡骨远端骨皮质变薄与骨质疏松相关,通过X线检查测量桡骨远端骨皮质厚度快速简便,可初步筛查骨量减少,并提示进一步行骨密度检查。
基金Supported by GRF of Hong Kong SAR (project no. 464508)a direct grant for research from the Chinese University of Hong Kong (project no.2041501)
文摘Objective To investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. Methods Orchiectomized and ovariectomized rat models are used to investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. A rat vertebral body can be longitudinally divided into central portion, which contain more trabecular bone, and para-endplate portions which contain more compact bone. In matured male and female Wistar and Sprague-Dawley rat lumbar spines, we investigated baseline bone mineral density （BMD） characteristics and the differential segmental responses in bone loss within the lumbar vertebral body post gonadal surgery with clinical multidetector computed tomography. Results Para-endplate sections had a higher BMD than central sections. The cephalad para-endplate sections had a higher BMD than the caudad para-endplate sections. Eight weeks after gonadal removal, there was more bone loss in central sections than para-endplate sections. The relative difference of bone loss between para-endplate and central sections was more apparent in male rats than in female rats. There was more bone loss in caudad sections than cephalad sections; this lead to a further increase of BMD difference between caudad para-endplate sections and cephalad para-endplate sections post gonadal surgery. Conclusion The approach described in this study provided a consistent way to study BMD change within predominantly compact bone portion and trabecular bone portion of the vertebral body.
