Anatomical Variation of the Tibia – a Principal Component Analysis

Abstract

Conventional anatomically contoured plates do not adequately fit most tibiae. This emphasizes the need for a more thorough morphological study. Statistical shape models are promising tools to display anatomical variations within a population. Herein, we aim to provide a better insight into the anatomical variations of the tibia and tibia plateau. Seventy-nine CT scans of tibiae were segmented, and a principal component analysis was performed. Five morphologically important parameters were measured on the 3D models of the mean tibial shapes as well as the −3SD and +3 SD tibial shapes of the first five components. Longer, wider tibiae are related to a more rounded course of the posterior column, a less prominent tip of the medial malleolus, and a more posteriorly directed fibular notch. Varus/valgus deformations and the angulation of the posterior tibia plateau represent only a small percentage of the total variation. Right and left tibiae are not always perfectly symmetrical, especially not at the level of the tibia plateau. The largest degree of anatomical variation of the tibia is found in its length and around the tibia plateau. Because of the large variation in the anatomy, a more patient-specific approach could improve implant fit, anatomical reduction, biomechanical stability and hardware-related complications.

Statistical shape modeling of the talocrural joint using a hybrid multi-articulation joint approach

“…Our presented tibial, fibular, and talar shape variations correspond with the limited literature available, which highlighted anatomical variation of the fibular notch on the tibia, talar trochlea sagittal plane rate of curvature, tibial plafond curvature with medial malleolus prominence, and changes in the fibular shaft diameter 17 , 18 , 20 , 24 . While our models had the limitation of not including the full-length tibia and fibula in our SSM analysis, we gained the ability to have higher resolution imaging in a weightbearing position to focus on more shape variation details within the distal tibia and fibula with weightbearing articular relationships and analyses in the talocrural joint.…”

“…Early SSM of the bones of the ankle were performed on 2D radiographs using manual landmark selection 21 . Advancements in 3D medical imaging and development of SSM algorithms have expanded the morphology literature in the foot and ankle 9 , 17 – 19 , 22 – 24 . Yet, a large limitation of SSM remains to be a lack of clinical interpretation of the PCA modes of variation.…”

Quantitative 3D measurements of tibial plateau fractures

“…Also, in the field of oral and maxillofacial surgery the use of 3D virtual planning and guided surgery is of substantial clinical value in order to perform complex jaw reconstructions within millimeters 17 . Recently, 3D statistical shape models of the tibia were introduced in this journal 18 . These models seem to be a promising tool for assessing anatomical variations and will be helpful in gaining a more patient-specific approach regarding fracture reduction techniques and implant fitting.…”

Towards Automated Ligamentous Injury Evaluation in Syndesmotic Ankle Lesions

“…Also, it was capable of adapting to unseen shapes and predicting corresponding syndesmotic ligaments, hence the generalization metric of our model. Previous shape models, by Tümer et al (30) and Quintens et al (31), focused mainly on anatomical variance of the separate tibia and fibula rather than the morphological variance of their articular congruence. Regarding compactness, these previous models show a high amount of variance in the first components.…”