title: Age-related variations in the microstructure of human tibial cancellous bone.
abstract: A thorough understanding of the microstructure of cancellous bone is crucial for diagnosis, prophylaxis, and treatment of age-related skeletal diseases. Until now, little has been known about age-related variations in the microstructure of peripheral cancellous bone. This study quantified age-related changes in the three-dimensional (3D) microstructure of human tibial cancellous bone. One hundred and sixty cylindrical cancellous bone specimens were produced from 40 normal proximal tibiae from 40 donors, aged 16-85 years. These specimens were micro-computed tomography (micro-CT) scanned, and microstructural properties were determined. The specimens were then tested in compression to obtain Young's modulus. The degree of anisotropy, mean marrow space volume, and bone surface-to-volume ratio increased significantly with age. Bone volume fraction, mean trabecular volume, and bone surface density decreased significantly with age. Connectivity did not have a general relationship with age. Bone volume fraction together with anisotropy best predicted Young's modulus. Age-related changes in the microstructural properties had the same trends for both medial and lateral condyles of the tibia. The observed increase of anisotropy and constant connectivity suggest a bone remodeling mechanism that may reorient trabecular volume orientation in aging tibial cancellous bone. The aging trabeculae align more strongly to the primary direction--parallel to the tibial longitudinal loading axis.
authors.affiliation: Department of Orthopaedics, Aarhus University Hospital, Denmark. ming@orl.auh.dk
authors.forename: Ming
authors.initials: M
authors.lastname: Ding
authors.forename: Anders
authors.initials: A
authors.lastname: Odgaard
authors.forename: Frank
authors.initials: F
authors.lastname: Linde
authors.forename: Ivan
authors.initials: I
authors.lastname: Hvid
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D016880:Anisotropy; D015519:Bone Density; D019245:Compressive Strength; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D013977:Tibia / Q000000981:diagnostic imaging* / Q000502:physiology; D014057:Tomography, X-Ray Computed / Q000379:methods