McGovern T F, Engh C A, Zettl-Schaffer K, Hooten J P
Anderson Orthopaedic Research Institute, Arlington, VA 22206.
Clin Orthop Relat Res. 1994 Sep(306):145-54.
A quantitative analysis of cortical bone remodeling was performed using calibrated videodensitometry. Six femoral specimens were obtained at autopsy from 3 patients treated with unilateral porous coated femoral components in situ > 6 years. Transverse thick sections of the remodeled and normal femora were obtained. Slab radiographs of the sections were analyzed using computer assisted videodensitometry. Detailed density plots of each section were constructed and the average density in defined quadrants was recorded. The density plots were also used to measure the cortical bone area present on each section. Two cases showed a gradient of resorptive remodeling change with the greatest density loss noted medially at the proximal levels (33% and 36%). The 3rd case had porotic cortical bone in the normal femur and demonstrated a different remodeling pattern, with the greatest average resorptive change (57%) measured in the midstem region. Changes in cortical area were variable: 1 showed cortical thickening in the midstem region; another had decreased cortical area in the entire region adjacent to the porous coating; and the 3rd had decreased cortical area proximally, with minimal changes noted in the distal levels. The volumetric densities measured by videodensitometry were compared with area densities measured with dual energy xray absorptiometry. There was a strong linear correlation between the 2 methods (r2 = 0.80).
使用校准视频密度测定法对皮质骨重塑进行了定量分析。从3例接受单侧多孔涂层股骨组件原位植入超过6年的患者尸检中获取了6个股骨标本。获取了重塑股骨和正常股骨的横向厚切片。使用计算机辅助视频密度测定法分析切片的平板X线片。构建了每个切片的详细密度图，并记录了定义象限内的平均密度。密度图还用于测量每个切片上的皮质骨面积。2例显示出吸收性重塑变化的梯度，近端水平内侧密度损失最大（33%和36%）。第3例正常股骨中有多孔皮质骨，并表现出不同的重塑模式，在骨干中部区域测得的平均吸收性变化最大（57%）。皮质面积的变化各不相同：1例显示骨干中部区域皮质增厚；另一例在与多孔涂层相邻的整个区域皮质面积减小；第3例近端皮质面积减小，远端水平变化最小。将视频密度测定法测得的体积密度与双能X线吸收法测得的面积密度进行比较。两种方法之间存在很强的线性相关性（r2 = 0.80）。
