{
  "abstract": "Bone mechanical competence depends not only on bone mass but also on the anisotropic orientation of the collagen/biological apatite (BAp) composite, yet its relationship to the local mechanical environment in human vertebrae remains unclear. Here, we examined whether region-specific BAp c-axis orientation corresponds to predominant principal stress direction estimated by µCT-based finite element analysis. The anterior region showed predominantly uniaxial alignment along the craniocaudal axis, corresponding to a predominant principal stress direction oriented primarily along the craniocaudal axis. In contrast, the cranial and caudal subchondral regions exhibited a two-dimensional in-plane orientation pattern corresponding to predominant principal stress directions within the anteroposterior-mediolateral plane, consistent with load transfer through the intervertebral disc, which imposes transverse in-plane loading on the endplate region. At the corticotrabecular junction, the preferred BAp orientation changed markedly within a spatial range of 100 μm or less. Overall, these findings demonstrate region-specific stress-orientation correspondence in human vertebrae and support crystallographic orientation as a quantitative bone-quality indicator of vertebral mechanical adaptation.",
  "abstract_shown": true,
  "affiliations": [
    "Division of Materials and Manufacturing Science, Graduate School of Engineering, The University of Osaka, 2-1, Yamadaoka, Suita, Osaka, 565-0871, Japan.",
    "R&D Department, Ratoc System Engineering Co., Ltd, Tokyo, Japan.",
    "Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.",
    "Department of Orthopaedic Surgery, Osaka Orthopedic Hospital, Osaka, Japan.",
    "Department of Orthopaedic Surgery, Shiraniwa Hospital, Nara, Japan.",
    "Division of Materials and Manufacturing Science, Graduate School of Engineering, The University of Osaka, 2-1, Yamadaoka, Suita, Osaka, 565-0871, Japan. nakano@mat.eng.osaka-u.ac.jp."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Toko Mori"
    },
    {
      "affs": [
        0
      ],
      "name": "Tadaaki Matsuzaka"
    },
    {
      "affs": [
        0
      ],
      "name": "Aira Matsugaki"
    },
    {
      "affs": [
        0
      ],
      "name": "Sayaka Miyabe"
    },
    {
      "affs": [
        1
      ],
      "name": "Nobuhito Nango"
    },
    {
      "affs": [
        2
      ],
      "name": "Yukihide Minoda"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Hiroyoshi Iwaki"
    },
    {
      "affs": [
        2,
        4
      ],
      "name": "Akio Kobayashi"
    },
    {
      "affs": [
        5
      ],
      "name": "Takayoshi Nakano",
      "orcid": "0000-0001-8052-1698"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/17fats235gtbr.bib",
  "cited_by": 0,
  "doi": "10.1007/s00223-026-01629-0",
  "fulltext_url": "https://europepmc.org/articles/PMC13694369",
  "id": "17fats235gtbr",
  "issns": [
    "0171-967X",
    "1432-0827"
  ],
  "landing_url": "https://europepmc.org/article/MED/42909634",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2732|Bone health and osteoporosis research"
    ]
  ],
  "openalex": "W7223300922",
  "pdf_url": "https://europepmc.org/articles/PMC13694369?pdf=render",
  "pmcid": "PMC13694369",
  "pmid": "42909634",
  "published": "2026-10-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/17fats235gtbr.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:03Z",
      "native_id": "MED:42909634",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42909634"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2732|Bone health and osteoporosis research",
      "subfield": "surgery"
    }
  ],
  "title": "Apatite c-axis Orientation Tracks Disc-Mediated Local Principal Stress Directions in the Human Lumbar Vertebra.",
  "title_text": "Apatite c-axis Orientation Tracks Disc-Mediated Local Principal Stress Directions in the Human Lumbar Vertebra.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:20:03Z",
  "url": "https://research.draconitic.com/paper/17fats235gtbr",
  "venue": "Calcified tissue international",
  "versions": []
}