Evaluation of thickness and appearance of anterior talofibular and calcaneofibular ligaments in normal versus abnormal ankles with MRI

Abstract

Injuries to the lateral ligaments of the ankle are common in medical practice. The most commonly injured ligaments are the anterior talofibular (ATFL) and calcaneofibular (CFL) ligaments. When undertaking MRI evaluation of ankle injuries it is important to understand the normal dimensions, appearance and variations of these ligaments. Twenty-eight consecutive patients referred for MRI of the ankle underwent bilateral scanning. The thickness of normal and abnormal ATFL and CFL was determined. The mean thickness of the ATFL was 2.19 +/- 0.6 mm and the CFL measured 2.13 +/- 0.5 mm. One normal ankle had an extremely thin ATFL (0.8 mm) with an otherwise normal appearance, whereas two ankles had an ATFL with a high attachment, both of which were deemed to be normal variants. Nineteen per cent of normal CFLs were noted to consist of a lateral hypointense band with a medial isointense medial band. Two variations of normal ATFL, one normal variant CFL and a measurement of the normal thickness of the ATFL and CFL have been presented in this paper. These variations have not been described previously by other authors. It is envisaged that these findings will assist in the MRI assessment of the lateral ankle ligaments.

The anterior talofibular ligament: A detailed morphological study

“…An MRI based study by Dimmick et al [4] reported ATFL thickness to be twice (2.19 mm) that of the current study (1.01 mm), with Hua et al [10] reporting ATFL thickness in normal ankles (1.46 mm) being less than in injured ankles (2.71 mm). Determining ligament dimensions from MRI images will to some extent be influenced by image resolution and slice thickness, and as such are not directly comparable to direct measurement.…”

“…The width was reported in a number of studies which was reported to be ranging between 4 mm and 12.98 mm [18,21,22,28,30]. Dimmick et al [4] and Hua et al [10] used MRI to measure ATFL thickness which was reported to be 2.19 mm and 1.46 mm respectively.…”

“…Maffulli et al [15] reported that the Brostrom technique is a safe procedure to restore sporting activity, although poor scores were reported in 21-24%, with recurrent instability in 16% of cases. Difficulties with some common surgical techniques have been reported [16][17][18], together with complications, including limitation of movement at the subtalar joint and ankle instability [4]. It is, therefore extremely important to have a good understanding of the relationship of the LCL complex, especially the ATFL, with respect to specific bony landmarks.…”

“…In the UK approximately 5000 ankle sprains occur every day with some 27,000 occurring in the USA [1,2]. Injury to the lateral collateral ligament (LCL) due to ankle inversion comprises about 85% of ankle sprains [3][4][5]. Moreover, isolated anterior talofibular ligament (ATFL) injury and combined ATFL and calcaneofibular (CFL) injuries occur in 80% and 20% of cases respectively.…”

Quantitative Assessment and Ligament Traceability of Volume Isotropic Turbo Spin Echo Acquisition (VISTA) Ankle Magnetic Resonance Imaging: Fat Suppression versus without Fat Suppression

“…The CFL extends proximally from the fibular tip, deep to the peroneal tendons, distally to the posterolateral calcaneus, which show long course through the fat tissue (29). The CR was expectedly superior in VISTA than in VISTA SPAIR between fat and CFL, which is attributable to the "undisclosive" effect due to signal loss of CFL by suppression of intraligamen- (31). Poor traceability of CFL might also be due to the signal intensity of healed/inherently heterogeneous-natured CFL which is similar to the adjacent suppressed fat.…”