Intact Anterior Talofibular Ligament Research Articles

Visibility of the lateral collateral ligaments in routine computed tomography of the ankle

Sir, I have read with great interest the article of Hua et al. [2] in a recent issue. They reported the detailed cross-sectional anatomy of the lateral collateral ligaments of the ankle on computed tomography (CT) and magnet resonance imaging (MRI). They used anatomic specimen and coated the ligaments with contrast media for CT imaging. Whether the ligaments could also be seen on CT scans in vivo was not addressed, but this could be a clinical relevant issue. Here routine CT scans of the ankle were reviewed. The sample consisted of eight patients; all patients were examined for purposes other than acute trauma to the ankle (imaging of orthopaedic hardware, arthrodesis, osteomyelitis, suspected complex regional pain syndrome) and had no clinical suspicion of ankle sprain. All patients were examined using the same 16-slice scanner with identical parameters (slice thickness 0.5 mm, 50 mA s, 120 kV) and were reviewed on a standard workstation. The anterior talofibular ligament could be clearly depicted in all patients as a hyperdense ligament (Fig. 1). The posterior talofibular ligament could be depicted in five of the eight patients and the calcaneofibular ligament could be depicted completely in three of the eight patients and in part in another two patients. Fig. 1 Axial slices of a computed tomography of the ankle in a soft tissue window (left) and a bone window setting (right). The anterior talofibular ligament could be easily depicted as a slight hyperdense ligament, especially in the soft tissue window setting ... Imaging of the lateral collateral ligaments is possible using arthrography, sonography and MRI, with MRI being the imaging method of choice in complicated or equivocal cases. CT has mostly been used to search for subtle fractures in complicated ankle sprains, but there are also a few reports about imaging of the ligaments [1, 3, 5]. In this small series the anterior talofibular ligament could be seen in all patients and the other ligaments in a large portion of patients. An intact anterior talofibular ligament could help to rule out a rupture of the lateral collateral ligaments, because it is the first to be torn in ankle sprains. This approach has been recently shown to be reliable for the imaging of the cruciate ligaments of the knee in CT imaging [4]. So clearly a large study to compare MRI and CT is warranted to establish the exact role of CT imaging of the lateral collateral ligaments and to make sure we use the full potential of the widespread available and often performed CT scans of the ankle.

Excursion and Strain of the Superficial Peroneal Nerve During Inversion Ankle Sprain

Traction is presumed to be the mechanism of injury to the superficial peroneal nerve in an inversion ankle sprain, but it is not known whether the amount of strain caused by nerve traction is sufficient to cause nerve injury. We hypothesized that the superficial peroneal nerve would experience significant excursion and strain during a simulated inversion sprain, that sectioning of the anterior talofibular ligament would increase excursion and strain, and that an impact force would produce strain in a range that can structurally alter the nerve. Differential reluctance transducers were placed in the superficial peroneal nerve in sixteen lower-extremity cadaver specimens to measure excursion and strain in situ. Static weight was applied to the foot in increments starting at 0.454 kg and ending at 4.54 kg. The anterior talofibular ligament was sectioned, and the measurements were repeated. A final impact force of 4.54 kg was applied to each specimen. Two-way repeated-measures analysis of variance was used to evaluate differences in excursion and strain. The mean excursion and strain of the superficial peroneal nerve increased with increases in the applied weight in both the group with the intact anterior talofibular ligament and the group in which it had been sectioned. Nerve excursion was greater in the sectioned-ligament group than in the intact-ligament group with all applied weights (p < 0.05). The mean nerve strain was greater in the sectioned-ligament group (range, 5.5% to 12.9%) than in the intact-ligament group (range, 3.0% to 11.6%) with application of the 0.454, 0.908, 1.362, and 1.816-kg weights (p < 0.05). With the ligament sectioned, the 4.54-kg impact force produced significantly higher mean nerve excursion and strain than did the 4.54-kg static weight (p < 0.05). The magnitude of strain with the impact force was in the lower range of values that have been shown to structurally alter peripheral nerves. The superficial peroneal nerve is at risk for traction injury during an ankle inversion sprain and is at additional risk with more severe sprains or with an insufficient anterior talofibular ligament.

A Study of Ruptures of the Lateral Ligament of the Ankle Joint : Clinical Technique and Cadaver Studies : International Session Abstracts of 45th Annual Meeting

This study reports the technique of the ankle stress roentgenogram for lateral ligament injury of stability of the ankle joint after a anteroposterior inversion stress and lateral sagittal stress and using maximum pressure of the 15 KP (Kilopascals) by the "Scheuba-Fixation device". In our opinion, the ankle stress roentgenography should be aided by mechanical assessment and to protect the examiner from unnecessary exposure to radiation should be concerned. The stress force can't be dependent on the examiner's evaluation after proper application of the device. We also reports the normal value of the ankle stress roentgenogram in 20 volunteers and on a biomechanical study of cadavers (10 cadavers, 20 ankles). The results in 20 volunteers of the talar tilt angle of supination inversion stress test is 2 degrees and talofibular gap is 5.4 mm and in the posterior hiatus of lateral sagittal stress test is 5.5 mm and talotibia length is 38 mm. Those data of the volunteers can be severed as basic clinical documentation. In the biomechanical study of cadavers, we divide into two groups; group I follows a complete rupture of anterior talofibular ligaments (ATF. L) with additional division of the rest lateral ligament, group II isolated division of two different lateral ligaments under intact anterior talofibular ligament. The results of cadaver study indicate that anterior talofibular ligament play a very important role in the ankle joint stability.