Ankle flexor torque, size and density are differential determinants of distal tibia trabecular plate-rod morphometry and bone strength: The Ankle Quality Study

Andy K O Wong; Hugo J W Fung; Adrian C H Chan; Eva Szabo; Sunita Mathur; Lora Giangregorio; Angela M Cheung

doi:10.1016/j.bone.2022.116582

Ankle flexor torque, size and density are differential determinants of distal tibia trabecular plate-rod morphometry and bone strength: The Ankle Quality Study

Bone. 2023 Jan:166:116582. doi: 10.1016/j.bone.2022.116582. Epub 2022 Oct 12.

Authors

Andy K O Wong¹, Hugo J W Fung², Adrian C H Chan³, Eva Szabo⁴, Sunita Mathur⁵, Lora Giangregorio⁶, Angela M Cheung⁷

Affiliations

¹ Joint Department of Medical Imaging, University Health Network, Toronto, ON, Canada; Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada; Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada. Electronic address: [email protected].
² Joint Department of Medical Imaging, University Health Network, Toronto, ON, Canada; Department of Exercise Sciences, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada.
³ Joint Department of Medical Imaging, University Health Network, Toronto, ON, Canada; Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada; Department of Medicine, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
⁴ Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada; Osteoporosis Program, Schroeder Arthritis Institute, University Health Network, Toronto, ON, Canada.
⁵ School of Rehabilitation Therapy, Queen's University, Kingston, ON, Canada.
⁶ Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, ON, Canada.
⁷ Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada; Osteoporosis Program, Schroeder Arthritis Institute, University Health Network, Toronto, ON, Canada; Department of Medicine, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.

PMID: 36243400
DOI: 10.1016/j.bone.2022.116582

Abstract

Hypothesis: Greater peak torque and higher myotendinous density at the ankle are associated with a more plate-like architecture at the distal tibia.

Methods: In this cross-sectional study, women and men ≥ 50 years old with no metal implants, reconstructive surgery, muscular dystrophies, or tendinopathies in any leg were recruited by convenience. Isometric ankle dorsi-plantar flexion and inversion-eversion peak torques were measured using dynamometry. HR-pQCT distal tibia scans were completed. Both assessments were completed on the same day on the non-dominant leg. Integral and trabecular vBMD were derived from standard analyses, failure load (FL) was obtained from finite element analysis, plate-specific parameters were computed from individual trabecula segmentation (ITS) analysis, myotendinous density (MyD) and volume fraction (MyV/TV) were computed from soft tissue analysis. pQCT scans of the 66 % mid-leg were performed (500 μm at 15 mm/s) to obtain muscle density (MD) and muscle cross-sectional area (MCSA).

Statistical analysis: General linear models estimated how ankle muscle group torque and muscle size and density differentially related, both separately and together, to whole-bone properties (integral vBMD, FL) and trabecular morphometry (ITS plate parameters). Models were adjusted for age, sex, BMI, use of glucocorticoids, current osteoarthritis, and participation in moderate to vigorous recreational or sport activities.

Results: Among 105 participants (77 % female, mean age: 63 (10) years, BMI: 25.8 (5.4) kg/m², 25 % with OA, 17 % fracture history, 42 % falls history), all torque measures, particularly ankle dorsiflexion and eversion, were correlates of plate-plate/rod junction density and failure load. However, muscle size and density measures were further associated with vBMD. The effect of greater ankle flexor-extensor torque on more connected bone was stronger when MyD was higher (interaction p < 0.001).

Conclusion: Strength of muscles around the ankle are correlates of plate-like trabeculae at the distal tibia, while leaner muscle and myotendinous tissues facilitates better quality bone for stronger ankle muscle torque.

Keywords: Ankle muscle group torque; HR-pQCT; Muscle size and density; Trabecular connectivity.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Ankle*
Bone Density / physiology
Cross-Sectional Studies
Female
Humans
Male
Middle Aged
Radius
Tibia* / diagnostic imaging
Torque