X-ray absorption spectroscopy is applied to investigate relationships between hierarchical organization of the skeleton and nanostructure of femoral bone in knee compartments and to understand the osteoarthritis (OA) related changes at the subcellular level. Our focus is on local electronic and atomic and molecular architectonics of the medial and lateral condyles of the femur resected during total knee arthroplasty in patients with medial compartmental knee OA. The element-specific and site-dependent peculiarities in spectral distributions of oscillator strength for core-to-valence transitions are revealed. The near Ca 2p and O 1s edges x-ray absorption fine structure (Ca 2p and O 1s NEXAFS) spectra of the saw cuts demonstrate substantial redistributions in intact and OA damaged areas on the proximal side, and on the proximal and distal sides of the samples. Examining the O 1s NEXAFS spectra new chemical bonds are revealed on the proximal surface in the OA areas. Strong intra-atomic intershell Ca²⁺ 23 interaction specifies the great similarity of the Ca 2p NEXAFS spectra. Their analysis performed in combination with the x-ray photoelectron data has demonstrated the formation of non-apatite calcium in the OA areas of the samples. It is shown that NEXAFS spectroscopy is a powerful tool for deeper understanding relationship between hierarchical skeletal organization and nanostructure of native bone. Perspectives for development of novel methods for medical imaging and diagnosis of subchondral bone at the nanolevel are discussed.

X 射线吸收光谱用于研究骨骼的分级组织与膝关节隔室中股骨的纳米结构之间的关系，并在亚细胞水平上了解骨关节炎 (OA) 相关变化。我们的重点是在内侧间室膝关节 OA 患者的全膝关节置换术期间切除的股骨内侧和外侧髁的局部电子和原子和分子结构。揭示了核到价跃迁的振荡器强度光谱分布中元素特定和位点相关的特性。锯切的近 Ca 2p 和 O 1s 边缘 X 射线吸收精细结构（Ca 2p 和 O 1s NEXAFS）光谱表明在近侧的完整和 OA 损伤区域有大量的重新分布，以及样品的近端和远端。检查 O 1s NEXAFS 光谱，在 OA 区域的近端表面上发现了新的化学键。强原子内壳层Ca²⁺ 2 3相互作用表明Ca 2p NEXAFS 光谱具有极大的相似性。他们结合 X 射线光电子数据进行的分析表明，在样品的 OA 区域中形成了非磷灰石钙。结果表明，NEXAFS 光谱是深入理解分层骨骼组织与天然骨纳米结构之间关系的有力工具。讨论了在纳米水平上开发用于医学成像和诊​​断软骨下骨的新方法的前景。