Methods ： fifty paired embalmed cadaveric humeri ( twenty-five pairs : fourteen from male donors and eleven from female donors ) were scanned in medial-lateral ( ml ) and anterior-posterior ( ap ) position according to the humeral retroversion by ct . images of the humeri in the transverse planes at the lowest border of neck ( lbn ), 20mm and 40mm distal of lbn ( lbn-20 、 lbn-40 ), isthmus, head-neck anterior-posterior ( hn-ap ) were obtained . sixty-one extracortical and intracortical parameters were measured exactly by image analytic computer software that included offset, head position, head-shaft angle, head to tuberosity height ( ht ), head thickness, curvature radius, articular surface arc ( sa ), neck diameter, isthmus position, proximal and distal border of isthmus, maximum coronal and sagittal diameter of medullary canal and thickness of cortical bone in four planes, including lbn, lbn-20, lbn-40 and isthmus 方法：50根成对防腐肱骨(男14对，女11对)按肱骨头扭转角置于冠状位和矢状位，行肱骨全长，头颈矢状面，解剖颈下缘及其下20mm、40mm，髓腔狭窄部四平面ct扫描，由ct软件测量冠、矢状位髓腔内外参数共61项，包括头心?干轴距，头位置，头干角，头?结节高度差，头厚度，头半径，关节面张角，解剖颈直径，髓腔狭窄部位置，解剖颈下缘及其下20mm、40mm和狭窄部四个平面髓腔的最大冠、矢状径，皮质骨厚度等。
Methods ： fifty paired embalmed cadaveric humeri ( twenty-five pairs : fourteen from male donors and eleven from female donors ) were scanned in medial-lateral ( ml ) and anterior-posterior ( ap ) position according to the humeral retroversion by ct . images of the humeri in the transverse planes at the lowest border of neck ( lbn ), 20mm and 40mm distal of lbn ( lbn-20 、 lbn-40 ), isthmus, head-neck anterior-posterior ( hn-ap ) were obtained . sixty-one extracortical and intracortical parameters were measured exactly by image analytic computer software that included offset, head position, head-shaft angle, head to tuberosity height ( ht ), head thickness, curvature radius, articular surface arc ( sa ), neck diameter, isthmus position, proximal and distal border of isthmus, maximum coronal and sagittal diameter of medullary canal and thickness of cortical bone in four planes, including lbn, lbn-20, lbn-40 and isthmus 方法：50根成对防腐肱骨(男14对，女11对)按肱骨头扭转角置于冠状位和矢状位，行肱骨全长，头颈矢状面，解剖颈下缘及其下20mm、40mm，髓腔狭窄部四平面ct扫描，由ct软件测量冠、矢状位髓腔内外参数共61项，包括头心?干轴距，头位置，头干角，头?结节高度差，头厚度，头半径，关节面张角，解剖颈直径，髓腔狭窄部位置，解剖颈下缘及其下20mm、40mm和狭窄部四个平面髓腔的最大冠、矢状径，皮质骨厚度等。
Methods ： fifty paired embalmed cadaveric humeri ( twenty-five pairs : fourteen from male donors and eleven from female donors ) were scanned in medial-lateral ( ml ) and anterior-posterior ( ap ) position according to the humeral retroversion by ct . images of the humeri in the transverse planes at the lowest border of neck ( lbn ), 20mm and 40mm distal of lbn ( lbn-20 、 lbn-40 ), isthmus, head-neck anterior-posterior ( hn-ap ) were obtained . sixty-one extracortical and intracortical parameters were measured exactly by image analytic computer software that included offset, head position, head-shaft angle, head to tuberosity height ( ht ), head thickness, curvature radius, articular surface arc ( sa ), neck diameter, isthmus position, proximal and distal border of isthmus, maximum coronal and sagittal diameter of medullary canal and thickness of cortical bone in four planes, including lbn, lbn-20, lbn-40 and isthmus 方法：50根成对防腐肱骨(男14对，女11对)按肱骨头扭转角置于冠状位和矢状位，行肱骨全长，头颈矢状面，解剖颈下缘及其下20mm、40mm，髓腔狭窄部四平面ct扫描，由ct软件测量冠、矢状位髓腔内外参数共61项，包括头心?干轴距，头位置，头干角，头?结节高度差，头厚度，头半径，关节面张角，解剖颈直径，髓腔狭窄部位置，解剖颈下缘及其下20mm、40mm和狭窄部四个平面髓腔的最大冠、矢状径，皮质骨厚度等。
Methods ： fifty paired embalmed cadaveric humeri ( twenty-five pairs : fourteen from male donors and eleven from female donors ) were scanned in medial-lateral ( ml ) and anterior-posterior ( ap ) position according to the humeral retroversion by ct . images of the humeri in the transverse planes at the lowest border of neck ( lbn ), 20mm and 40mm distal of lbn ( lbn-20 、 lbn-40 ), isthmus, head-neck anterior-posterior ( hn-ap ) were obtained . sixty-one extracortical and intracortical parameters were measured exactly by image analytic computer software that included offset, head position, head-shaft angle, head to tuberosity height ( ht ), head thickness, curvature radius, articular surface arc ( sa ), neck diameter, isthmus position, proximal and distal border of isthmus, maximum coronal and sagittal diameter of medullary canal and thickness of cortical bone in four planes, including lbn, lbn-20, lbn-40 and isthmus 方法：50根成对防腐肱骨(男14对，女11对)按肱骨头扭转角置于冠状位和矢状位，行肱骨全长，头颈矢状面，解剖颈下缘及其下20mm、40mm，髓腔狭窄部四平面ct扫描，由ct软件测量冠、矢状位髓腔内外参数共61项，包括头心?干轴距，头位置，头干角，头?结节高度差，头厚度，头半径，关节面张角，解剖颈直径，髓腔狭窄部位置，解剖颈下缘及其下20mm、40mm和狭窄部四个平面髓腔的最大冠、矢状径，皮质骨厚度等。
