Computer tomographic evaluation of talar edge configuration for osteochondral graft transplantation

Abstract

To successfully surgically reconstruct osteochondral lesions of the talus, the exact three-dimensional (3D) configuration of the upper articular surface of the talus has to be respected. We assessed the talar geometry by measuring the coronal and sagittal talar edge radius and the frontal talar profile in multiplanar reconstructions of computer tomographic (CT) studies of 79 patients (83 feet) with a healthy ankle joint. An image visualization software designated for coordinate measurement was used to perform the measurement. In the coronal plane, the mean lateral talar edge radius was 4.0 mm and the medial 4.5 mm. In the sagittal planes the mean lateral talar edge radius was 20.3 mm, the radius of the sulcus 20.7 mm and the medial talar edge radius 20.4 mm. The talus showed a concave shape in coronal cuts. These results show a significant difference between medial and lateral talar edge configuration in coronal planes. The measurements of the lateral and medial sagittal radius and the mid-sagittal radius in the sulcus tali show no statistically significant difference. The depth of the talar sulcus shows no correlation to age or sex. Different sizes of custom-made tissue-engineered grafts according to the location of the osteochondral lesion at the talus are needed for exact surgical reconstruction of the anatomy. Osteochondral lesions are three dimensional; therefore, a 3D preoperative planning tool by CT scan or MRI is mandatory.

Talar Dome Investigation and Talocrural Joint Axis Analysis Based on Three-Dimensional (3D) Models: Implications for Prosthetic Design

“…On the one hand, intrinsic error could exist when measuring cadaver specimens or manually determining subject points on the three-dimensional (3D) reconstructed model. Thus, the coordinate system established by the landmarks might not be accurate [10, 11, 22–25]. On the other hand, not many studies positioned the foot and lower extremity in the neutral position, in which both the longitudinal axis of the second metatarsal and mechanical axis were parallel to the sagittal plane of gantry during CT image collection [26].…”

Three‐dimensional analysis of talar trochlea morphology: Implications for subject‐specific kinematics of the talocrural joint

“…Contrary to the conventional concept, Siegler et al (), using 3D image‐based bone models, demonstrated that the talar trochlea can be modeled as a truncated cone with its apex oriented laterally. Although most morphological studies of the talar trochlea (Siegler et al, ; Wiewiorski et al, ) have been conducted with the assumption that the talocrural joint is a one‐degree‐of‐freedom joint with a fixed axis of rotation, in vivo kinematic studies (Latimer et al, ; Lundberg et al, ) have demonstrated that the axis of rotation for the talocrural joint changes throughout the dorsiflexion and plantarflexion motions.…”

A Novel Computational Method for Evaluating Osteochondral Autografts in Distal Radius Reconstruction

“…More sophisticated measurement techniques relying on three-dimensional CT scan imaging are available, however. One study of the talar contour used CT scan images to reconstruct a three-dimensional image of the talus and measured depth and radius of curvature at several locations [18]. These authors demonstrated that in the coronal plane, the medial edge radius of curvature and the lateral edge radius of curvature are significantly different [18].…”

“…One study of the talar contour used CT scan images to reconstruct a three-dimensional image of the talus and measured depth and radius of curvature at several locations [18]. These authors demonstrated that in the coronal plane, the medial edge radius of curvature and the lateral edge radius of curvature are significantly different [18]. This finding calls into question the adequacy of manual, twodimensional measurement techniques such as application of circular templates to a radiograph to estimate radius of curvature since osteochondral grafts are by nature threedimensional.…”