Metzger Corinne E, Newman Christopher L, Tippen Samantha P, Golemme Natalie T, Chen Neal X, Moe Sharon M, Allen Matthew R
Department of Anatomy, Cell Biology, and Physiology, Indianapolis, IN, USA, 46202.
Department of Radiology and Imaging Sciences, Indianapolis 46202, IN, USA.
Bone Rep. 2022 Aug 17;17:101612. doi: 10.1016/j.bonr.2022.101612. eCollection 2022 Dec.
Cortical porosity develops in chronic kidney disease (CKD) and increases with progressing disease. Cortical porosity is likely a prominent contributor to skeletal fragility/fracture. The degree to which cortical porosity occurs throughout the skeleton is not fully known. In this study, we assessed cortical bone porosity via micro-computed tomography at multiple skeletal sites in rats with progressive chronic kidney disease. We hypothesized that cortical porosity would occur in long bones throughout the body, but to a lesser degree in flat bones and irregular bones. Porosity was measured, using micro-CT, at 17 different skeletal sites in 6 male rats with CKD. Varying degrees of porosity were seen throughout the skeleton with higher porosity in flat and irregular bone (i.e. parietal bone, mandible) vs. long bones (p = 0.01) and in non-weightbearing bones vs. weightbearing bones (p = 0.01). Porosity was also higher in proximal sites vs. distal sites in long bones (p < 0.01 in all comparisons). There was large heterogeneity in porosity within skeletal sites across rats and within the same rat across skeletal sites. Correlations showed cortical porosity of the proximal tibia was positively associated with porosity at the other sites with the strongest correlation to the parietal bone and the weakest to the ulna. Overall, our data demonstrates varying and significant cortical bone porosity across the skeleton of animals with chronic kidney disease. These data point to careful selection of skeletal sites to assess porosity in pre-clinical studies and the potential for fractures at multiple skeletal sites in patients with CKD.
皮质骨孔隙率在慢性肾脏病（CKD）中会出现，并随着疾病进展而增加。皮质骨孔隙率很可能是导致骨骼脆弱/骨折的一个重要因素。目前尚不完全清楚整个骨骼中皮质骨孔隙率出现的程度。在本研究中，我们通过显微计算机断层扫描评估了进行性慢性肾脏病大鼠多个骨骼部位的皮质骨孔隙率。我们假设全身长骨都会出现皮质骨孔隙率，但扁骨和不规则骨中的程度较轻。使用显微CT对6只患有CKD的雄性大鼠的17个不同骨骼部位进行了孔隙率测量。在整个骨骼中都观察到了不同程度的孔隙率，扁骨和不规则骨（即顶骨、下颌骨）中的孔隙率高于长骨（p = 0.01），非负重骨中的孔隙率高于负重骨（p = 0.01）。长骨近端部位的孔隙率也高于远端部位（所有比较中p < 0.01）。大鼠之间以及同一大鼠的不同骨骼部位之间，骨骼部位内的孔隙率存在很大异质性。相关性分析表明，胫骨近端的皮质骨孔隙率与其他部位的孔隙率呈正相关，与顶骨的相关性最强，与尺骨的相关性最弱。总体而言，我们的数据表明，患有慢性肾脏病的动物整个骨骼中皮质骨孔隙率各不相同且差异显著。这些数据表明，在临床前研究中评估孔隙率时要谨慎选择骨骼部位，并且CKD患者多个骨骼部位存在骨折的可能性。
