Depth-specific characterization of bone microarchitecture in the femoral head: implications for osteoarthritis and osteoporosis research
- 1Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
- 2Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
Abstract
Background: Osteoarthritis (OA) and osteoporosis (OP) are highly prevalent musculoskeletal diseases characterized by cartilage loss and increased subchondral bone formation and by systemic bone mass reduction, respectively. The femoral head is commonly examined in both OA and OP research, yet both conditions may coexist in the same patient, making it unclear how local cartilage degeneration and systemic bone mineral density (BMD), as a marker of OP-related skeletal status, contribute to bone microarchitectural changes at different depths.
Methods: Femoral heads were obtained from 30 patients undergoing primary total hip arthroplasty for hip OA. Ex vivo high-resolution peripheral quantitative computed tomography (HR-pQCT) was performed on the entire femoral head, followed by computational segmentation of the subchondral mineralized plate (SMP) and five concentric trabecular regions. Depth-specific bone microarchitectural parameters were analyzed in relation to histologically assessed cartilage degeneration and systemic BMD measured by dual-energy X-ray absorptiometry (DXA).
Results: The cohort had a mean age of 75.4 ± 9.5 years, 53.3% were female, and patients spanned the spectrum of normal BMD (36.7%), osteopenia (46.7%), and osteoporosis (16.7%). Trabecular volumetric tissue mineral density (Tb.vTMD), bone volume to tissue volume (BV/TV), and trabecular thickness (Tb.Th) showed an initial decrease in the superficial trabecular regions, followed by a progressive increase toward deeper regions, whereas cyst-like void volume continuously decreased with depth and almost completely disappeared beyond 9.84 mm in depth. Cartilage degeneration independently predicted subchondral bone microstructure within the SMP and in superficial to intermediate trabecular regions (up to 13.12 mm in depth). Specifically, higher OARSI grades were associated with higher SMP.Th, Tb.vTMD, BV/TV, and Tb.Th. Systemic BMD T-score emerged as an independent predictor of trabecular bone parameters across all depths and represented the sole determinant of BV/TV and Tb.Th in the deepest trabecular region (beyond 13.12 mm depth), while cartilage degeneration was not associated with trabecular bone parameters in the deepest trabecular region.
Conclusions: Our findings showcase spatially distinct contributions of cartilage degeneration and systemic skeletal status to subchondral bone remodeling, identifying depth as a critical determinant in the analysis of osteochondral alterations in hip OA. Specifically, our findings emphasize that systemic BMD should be considered a covariate in OA research and that deep regions of the femoral head should be used for OP research to minimize potential confounding by local OA-related effects.
Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1186/s13075-026-03943-2.
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BibTeX
@article{simon2026depthspecific,
title = {{Depth-specific characterization of bone microarchitecture in the femoral head: implications for osteoarthritis and osteoporosis research}},
author = {Alexander Simon and Assil-Ramin Alimy and Johannes Krug and Björn Busse and Frank Timo Beil and Michael Amling and Felix N. von Brackel and Tim Rolvien},
journal = {Arthritis Research \& Therapy},
year = {2026},
month = nov,
doi = {10.1186/s13075-026-03943-2},
url = {https://doi.org/10.1186/s13075-026-03943-2},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Depth-specific characterization of bone microarchitecture in the femoral head: implications for osteoarthritis and osteoporosis research
AU - Alexander Simon
AU - Assil-Ramin Alimy
AU - Johannes Krug
AU - Björn Busse
AU - Frank Timo Beil
AU - Michael Amling
AU - Felix N. von Brackel
AU - Tim Rolvien
PY - 2026
DA - 2026/11/03
JO - Arthritis Research & Therapy
DO - 10.1186/s13075-026-03943-2
UR - https://doi.org/10.1186/s13075-026-03943-2
AB - Background: Osteoarthritis (OA) and osteoporosis (OP) are highly prevalent musculoskeletal diseases characterized by cartilage loss and increased subchondral bone formation and by systemic bone mass reduction, respectively. The femoral head is commonly examined in both OA and OP research, yet both conditions may coexist in the same patient, making it unclear how local cartilage degeneration and systemic bone mineral density (BMD), as a marker of OP-related skeletal status, contribute to bone microarchitectural changes at different depths. Methods: Femoral heads were obtained from 30 patients undergoing primary total hip arthroplasty for hip OA. Ex vivo high-resolution peripheral quantitative computed tomography (HR-pQCT) was performed on the entire femoral head, followed by computational segmentation of the subchondral mineralized plate (SMP) and five concentric trabecular regions. Depth-specific bone microarchitectural parameters were analyzed in relation to histologically assessed cartilage degeneration and systemic BMD measured by dual-energy X-ray absorptiometry (DXA). Results: The cohort had a mean age of 75.4 ± 9.5 years, 53.3% were female, and patients spanned the spectrum of normal BMD (36.7%), osteopenia (46.7%), and osteoporosis (16.7%). Trabecular volumetric tissue mineral density (Tb.vTMD), bone volume to tissue volume (BV/TV), and trabecular thickness (Tb.Th) showed an initial decrease in the superficial trabecular regions, followed by a progressive increase toward deeper regions, whereas cyst-like void volume continuously decreased with depth and almost completely disappeared beyond 9.84 mm in depth. Cartilage degeneration independently predicted subchondral bone microstructure within the SMP and in superficial to intermediate trabecular regions (up to 13.12 mm in depth). Specifically, higher OARSI grades were associated with higher SMP.Th, Tb.vTMD, BV/TV, and Tb.Th. Systemic BMD T-score emerged as an independent predictor of trabecular bone parameters across all depths and represented the sole determinant of BV/TV and Tb.Th in the deepest trabecular region (beyond 13.12 mm depth), while cartilage degeneration was not associated with trabecular bone parameters in the deepest trabecular region. Conclusions: Our findings showcase spatially distinct contributions of cartilage degeneration and systemic skeletal status to subchondral bone remodeling, identifying depth as a critical determinant in the analysis of osteochondral alterations in hip OA. Specifically, our findings emphasize that systemic BMD should be considered a covariate in OA research and that deep regions of the femoral head should be used for OP research to minimize potential confounding by local OA-related effects. Supplementary Information: The online version contains supplementary material available at https://doi.org/10.1186/s13075-026-03943-2.
SN - 1478-6354
SN - 1478-6362
ER -