Quantitative Analysis of Deltoid Ligament Degradation in Patients With Chronic Ankle Instability Using Computed Tomographic Images

Abstract

Background: Rotational ankle instability (RAI) is associated with the faster onset of severe ankle osteoarthritis via dysfunction of the anterior talofibular ligament, calcaneofibular ligament, and deltoid ligament. No specific clinical examination is available for RAI, and diagnostic imaging has limitations in evaluating ligament degradation. This study investigated the deltoid ligament degeneration using Hounsfield unit (HU) values on computed tomography (CT) images. Methods: Patients were enrolled in this retrospective analysis if they had undergone magnetic resonance imaging (MRI) and CT scans of the ankle. The chronic ankle instability (CAI) group comprised 20 ankles with CAI (9 men, 11 women; mean age, 28.7 years) and the control group comprised 28 ankles (16 men, 12 women, mean age, 41.3 years). The average HU values of the deep posterior tibiotalar ligament (dPTL) that constitutes the deltoid ligament were measured on coronal CT images, and MRI results were used as a reference. All patients were subdivided based on the MRI findings of dPTL injury such as fascicular disruption, irregularity, and the loss of striation. Results: A strong negative correlation was identified between age and HU values for all patients (Spearman ρ = −0.63; P < .001). The mean HU values of the dPTL for participants aged <60 years were 81.0 HU for the control group (21 ankles) and 69.5 HU for the CAI group ( P = .0075). No significant differences in the HU values were observed for the dPTL among the MRI subgroups. Conclusion: In addition to the conventional imaging examination such as stress radiographs and MRI, HU measurements of CT images could be useful for quantitatively and noninvasively evaluating degenerative changes in the deltoid ligament for CAI patients to assist the diagnosis of RAI. Level of Evidence: Level III. case-control study.

A Preliminary Study to Assess the Relevance of Shear-Wave Elastography in Characterizing Biomechanical Changes in the Deltoid Ligament Complex in Relation to Ankle Position

“…37 Another cross-sectional imaging alternative is the computed tomographic scan, which has shown its usefulness in daily clinical practice. 6,28 Nevertheless, cross-sectional imaging by magnetic resonance imaging or computed tomographic scan does not allow dynamic investigation. Ultrasonography is a good alternative because it allows dynamic study of the ankle ligaments.…”

“…Twenty consecutive subjects (10 females, 10 males), all residents or medical students of the department, with a mean age of 22.2 years (range [22][23][24][25][26][27][28][29][30][31] were enrolled in the study between November 2020 and January 2021. A questionnaire was administered to ensure the absence of any medical history of fracture, sprain, or ankle surgery.…”

Ankle Instability Update

“…69 CAI and deltoid ligament injuries lead to a faster onset of OA. 37 Ankle OA usually occurs in younger productive-age individuals, progressing more rapidly to advanced stages and resulting in longer time with pain and loss of function. Clinical studies on the subject have shown that displacements of the talus of up to 1 mm with respect to the articular surface of the distal tibia can cause loss of tibiotalar contact of up to 42%.…”

“…12 Patients with chronic lateral ankle instability may develop rotatory ankle instability, secondary to a combination of lateral and medial lesions, usually after a long history of lateral ankle symptoms. [35][36][37] It is defined as an abnormal increase of talar rotation within the tibiofibular mortise due to ATFL deficiency, combined with CFL and deltoid ligament injuries. Secondary to chronic deficiency of the lateral ligaments, the talus goes into excessive internal rotation and anterior translation and increases the stress at the most anterior fascicles of the deltoid ligament, leading to rupture or detachment of the most anterior component of the deltoid ligaments, especially the superficial deltoid complex.…”

“…In chronic RAI, the talus ultimately falls medially with talonavicular subluxation, leading to lesions of the spring complex and secondary acquired flatfoot. 8,[35][36][37] Clinical assessment is difficult because patients can have absence of medial pain; MRI is useful to rule out these lesions. Special attention should be directed toward evaluating its medial malleolar origin.…”