Bilateral Symmetry, Sex Differences, and Primary Shape Factors in Ankle and Hindfoot Bone Morphology

Abstract

Background: Ankle injuries and joint degeneration may be related to ankle bone morphology. Little data exist to characterize healthy hindfoot bone morphology. The purpose of this study was to characterize side-to-side symmetry and sex differences in ankle and hindfoot bone morphology, and to identify the primary shape factors that differentiate ankle and hindfoot bone morphology among individuals. Methods: Computed tomography was used to create 3D surface models of the distal tibia, talus, and calcaneus for 40 ankle and hindfoot bones from 20 healthy individuals. Morphologic differences between left and right bones of the same individual and between males and females were determined. Statistical shape modeling was performed to identify primary shape variations among individuals. Results: Side-to-side differences in bone morphology averaged 0.79 mm or less. The average distal tibia in males was larger overall than in females. No significant sex difference was noted in the tali. The average female calcaneus was longer and thinner than the average male calcaneus. Variability in ankle and hindfoot bone morphology is primarily associated with articulating surface shape, overall length and width, and tendon/ligament attachment points. Conclusion: In general, the contralateral ankle can serve as an accurate guide for operative restoration of native ankle morphology; however, specific regions demonstrate higher asymmetry. Clinical Relevance: Knowledge of regions of high and low bilateral symmetry can improve hindfoot and ankle reconstruction. Design of ankle prostheses can be improved by accounting for differences in bone morphology associated with sex and shape differences among individuals.

Unique shape variations of hind and midfoot bones in flatfoot subjects—A statistical shape modeling approach

“…the variety was such that not even a standardized 10 cm above the ankle joint cut-off could be attempted (Gabrielli et al, 2020). Incorporating muscle and ligament modeling would allow for an in-depth analysis of the association of isolated spring ligament tears, degeneration of the deltoid ligament, and posterior tibial tendon dysfunctions to certain shape variations (Bastias et al, 2018;Lin et al, 2015;Ling & Lui, 2017;Masaragian et al, 2020).…”

“…Nine PC modes were extracted for each joint along with each individual subject's weighted shape parameter for each PC, indicating how far a subject's geometry is from the average for a specific PC (Figure 1). Nine PC modes were selected as later modes can refer to noise and too subtle changes to notice (Gabrielli et al, 2020; Tümer, Vuurberg, et al, 2019). These principal components are referred to further as modes of variation to better visualize the shape changes.…”

“…SSMs have emerged over the past 5 years to analyze the anklefoot complex. Initial studies focused on defining and refining SSM methods for the bones of the feet (Grant et al, 2020;Melinska et al, 2015Melinska et al, , 2017, before comparative studies reported differences between genders and ethnicities in tibia, calcaneus, and talus geometry (Gabrielli et al, 2020;Nelson et al, 2017;Tümer, Arbabi, et al, 2019). Normal population reference values for the talocrural and subtalar joints were defined by comparing ±2SD of the normal shape variation for the talus, calcaneus, tibia, and fibula bones (Krähenbühl et al, 2020;Lenz et al, 2021).…”

Syndesmosis Repair Affects in Vivo Distal Interosseous Tibiofibular Ligament Elongation Under Static Loads and During Dynamic Activities

“…Three-dimensional bone models were made from segmented bone tissue 36 . Anatomic coordinate systems were created for each bone in the right foot with use of an automated algorithm and were mirrored to the left side after co-registering each corresponding bone 37,38 (Fig. 3-D).…”

Multi-level multi-domain statistical shape model of the subtalar, talonavicular, and calcaneocuboid joints

“…Using SSM, a statistical model can be created to compare mean bone shape morphology and identify anatomical modes of variation. Previous ankle SSM studies have been limited to a single bone and could not, therefore, evaluate multi-domain joint relationships ( Melinska et al, 2015 ; Melinska et al, 2017 ; Tümer et al, 2019a ; Tümer et al, 2019b ; Gabrielli et al, 2020 ; Krähenbühl et al, 2020 ; Liu et al, 2020 ; Schmutz et al, 2021 ; Arbabi et al, 2022 ; Peiffer et al, 2022 ; Vafaeian et al, 2022 ). A multi-domain technique can be implemented to capture morphological and alignment changes for multiple bones throughout a population.…”