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Surg Radiol Anat (2013) 35:283293 DOI 10.1007/s00276-012-1069-x
ORIGINAL ARTICLE
Micro CT analysis of the subarticular bone structure in the area of the talar trochlea
Andrej Maria Nowakowski Hans Deyhle
Silvan Zander Andr Leumann
Magdalena Mller-Gerbl
Received: 22 July 2012 / Accepted: 22 December 2012 / Published online: 10 January 2013 The Author(s) 2013. This article is published with open access at Springerlink.com
AbstractPurpose Certain regions of the talar trochlea are recognized as exhibiting varying cartilage thickness and degrees of subchondral bone mineralization. These changes have been attributed to the long-term loading history. For the current study, we accepted the hypothesis that stress-induced alterations of the joint surface include not only varying degrees of subchondral lamellar mineralization, but also structural changes of the subarticular cancellous bone.
Methods In order to examine the structure of the subarticular cancellous bone, ten formalin-xed talar trochleae were analyzed using micro CT. Sixteen measurement zones were dened and then evaluated in ve layers each of 1-mm thickness, enabling assessment of the cancellous architecture extending 5 mm below the trochlear surface using numerical and structural parameters.
Results As with mineralization patterns in the subchondral lamella, large variation was observed regarding bone volume, trabecular quantity, thickness, and spacing, as well as for structure model index and degree of anisotropy, depending on localization. In addition, like previous reports examining mineralization of the subchondral
lamella, two distinct groups could be identied as bicentric or monocentric.
Conclusions These results show that structural tissue adaptation probably due to loading history is also evident within the subarticular cancellous bone.
Keywords Loading history Trabecular meshwork
Numerical parameter Structural parameter Micro CT
Introduction
The articular surfaces of the upper ankle are stressed primarily by axial compression through a vertical load vector [10]. However, bending load is also exerted by tension from the collateral ligaments [18].
Close [3] and Fick [7] reported increasing intermalleolar distance on dorsiexion of the foot. This also exposes the talus to exural stress. Similarly, Calhoun et al. [2] found that under stress in dorsiexion, the medial and lateral contact areas of the malleolar articular surfaces are enlarged.
Because of physiological incongruence, only certain parts of the opposing talocrural articulating surfaces are available to absorb load [10]. In previous studies of various joints, Muller-Gerbl [9, 11]...