In Vivo Kinematics of the Talocrural and Subtalar Joints With Functional Ankle Instability During Weight-Bearing Ankle Internal Rotation

Abstract

Functional ankle instability (FAI) may involve abnormal kinematics. However, reliable quantitative data for kinematics of FAI have not been reported. The objective of this study was to determine if the abnormal kinematics exist in the talocrural and subtalar joints in patients with FAI. Five male subjects with unilateral FAI (a mean age of 33.4 ± 13.2 years) were enrolled. All subjects were examined with stress radiography and found to have no mechanical ankle instability (MAI). Lateral radiography at weight-bearing ankle internal rotation of 0° and 20° was taken with the ankle at 30° dorsiflexion and 30° plantar flexion. Patients underwent computed tomography scan at 1.0 mm slice pitch spanning distal one third of the lower leg and the distal end of the calcaneus. Three-dimensional (3D) kinematics of the talocrural and subtalar joints as well as the ankle joint complex (AJC) were determined using a 3D-to-2D registration technique using a 3D-to-2D registration technique with 3D bone models and plain radiography. FAI joints in ankle dorsiflexion demonstrated significantly greater subtalar internal rotation from 0° to 20° internal rotation. No statistical differences in plantar flexion were detected in talocrural, subtalar or ankle joint complex kinematics between the FAI and contralateral healthy joints. During ankle internal rotation in dorsiflexion, FAI joints demonstrated greater subtalar internal rotation. The FAI joints without mechanical instability presented abnormal kinematics. This suggests that abnormal kinematics of the FAI joints may contribute to chronic instability. FAI joints may involve unrecognized abnormal subtalar kinematics during internal rotation in ankle dorsiflexion which may contribute to chronic instability and frequent feelings of instability.

Fibular Malalignment in Individuals With Chronic Ankle Instability

“…53,55 Lateral displacement of the fibula widens the distal tibiofibular joint, affecting the mortise structure, and is associated with excessive talar rotation. Previous in vivo studies have shown an increase in talar anterior translation, 6,32 inversion, 6 and internal rotation 6,31 in the ankles with CAI. Thus, complex analyses that include examination of talocrural joint alignment or kinematics, as well as investigation of the distal tibiofibular joint, will be required in the future.…”

“…31,32,56 Average interobserver difference of the anatomical coordinate systems was 0.35 mm in translation and 0.76° in rotation, and average intraobserver difference was 0.35 mm in translation and 0.85° in rotation (FIGURE 1). 56…”

Accuracy and feasibility of high-speed dual fluoroscopy and model-based tracking to measure in vivo ankle arthrokinematics

“…Ankle range of motion (ROM) was simulated about three axes of rotation: dorsi-plantar flexion, inversion-eversion and internal-external rotation by manipulating the implanted tibia rod M a n u s c r i p t 6 with the toes taped to the stationary treadmill. DF images were acquired at 100 Hz.…”

“…Intra-cortical pins with reflective markers have independently tracked the tibia, talus, and calcaneus [4,5], but this approach is highly invasive. Other studies have used single plane fluoroscopy to study invivo motions of the ankle [6][7][8]. However, out-of-plane motions, such as axial rotation of the subtalar joint, cannot be accurately measured with single plane fluoroscopy [9].…”

Biplane fluoroscopy for hindfoot motion analysis during gait: A model-based evaluation

“…The radiographic nature of fluoroscopy also allows for gait analysis during shoe wear, brace wear, and orthotic usage that is not achievable using optical motion analysis with external markers. Two-dimensional (2D) in vivo fluoroscopic analysis of the hindfoot has been reported by both our group and other authors [14][15][16][17][18][19][20][21][22]. While these 2D analyses are valuable for quantifying single plane dynamics, they lack the ability to determine out of plane motions, such as axial rotation of the subtalar joint [23,24].…”