Four-dimensional CT as a valid approach to detect and quantify kinematic changes after selective ankle ligament sectioning

Abstract

The objective of the current study was to explore the potential of dynamic computed tomography to detect kinematic changes, induced by sequential sectioning of the lateral collateral ligaments of the ankle, during full motion sequence of the talocrural joint. A custom-made device was used to induce cyclic controlled ankle inversion movement in one fresh frozen cadaver leg. A 256-slice CT scanner was used to investigate four different scenarios. Scenario 1 with all ligaments intact was first investigated followed by sequential section of the anterior talo-fibular ligament (Scenario 2), the calcaneo-fibular ligament (Scenario 3) and posterior talo-fibular ligament (Scenario 4). Off-line image processing based on semi-automatic segmentation and bone rigid registration was performed. Motion parameters such as translation, rotational angles and orientation and position of the axis of rotation were calculated. Differences between scenarios were calculated. Progressive increase of cranio-caudal displacement up to 3.9 mm and flexion up to 10° compared to Scenario 1 were reported. Progressive changes in orientation (up to 20.6°) and position (up to 4.1 mm) of the axis of rotation were also shown. Estimated effective dose of 0.005 mSv (1.9 mGy CTDIvol) was reported. This study demonstrated that kinematic changes due to the absence of ligament integrity can be detected with 4DCT with minimal radiation exposure. Identifying abnormal kinematic patterns could have future application in helping clinicians to choose patients’ optimal treatment. Therefore, further studies with bigger in vitro sample sizes and consequent investigations in vivo are recommended to confirm the current findings.

Centre of Rotation of the Human Subtalar Joint Using Weight-Bearing Clinical Computed Tomography

“…been reported. Recent studies have shown the potential of four-dimensional (4D) CT to evaluate subtalar joint kinematics and detect changes between healthy and pathological subjects both ex vivo 36 and in vivo 37 . However, all previous literature reports images acquired with subjects placed in the CT scanner table in a supine position and, although custom-built ankle loading devices are commonly used, images acquired are not in a weight-bearing configuration. During weight-bearing, the combination of tensile loading of the ligaments and compression loading of all the joints of the foot creates a more tightly joined and stable architecture when compared to a non-weight-bearing situation 19 .…”

Four-Dimensional CT Assessment of the Transverse Carpal Ligament Attachments-A Pilot Study

“…This technique does not utilise 3D volume rendering technology, and has a higher associated error rate than the technique outlined in this study. More recently, 4D CT has been used in cadaveric studies of the ankle to quantify kinematic changes following ligament sectioning [23]. Similarly, there have been other studies focused on scapholunate instability and calculating angles using 4D-CT [24].…”

Automated Motion Analysis of Bony Joint Structures from Dynamic Computer Tomography Images: A Multi-Atlas Approach

“…Dynamic computer tomography (4D-CT) enables acquisition of a series of high temporal-resolution 3D CT datasets of moving structures. Various phantom studies [6][7][8][9] demonstrated the validity and feasibility of dynamic CT for evaluating MSK diseases. Several patient studies have been conducted investigating different joint disorders of the wrist, knee, hip, shoulder and foot [10][11][12].…”

“…Several authors have proposed methods to account for sliding motion [16,17], but most rely on prior segmentations of bones of interest. Motion estimation of MSK structures is therefore commonly performed using prior manual segmentations of the bony structures, limiting registration to a region of interest and obtaining individual bone motion to facilitate estimation of kinematics [6,8]. However, manual bone segmentation is labor intensive and hinders application in clinical routine.…”