Anatomic Measurement and Variability Analysis of the Anterior Talofibular Ligament and Calcaneofibular Ligament of the Ankle

Background: The anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) contribute greatly to the overall stability of the ankle joint; however, ATFL and combined ATFL-CFL sprains are common. Anatomic reconstruction of the lateral collateral ligament with grafts has been proposed for patients with poor tissue quality or inadequate local tissue. Anatomic reconstruction of the lateral ankle ligaments requires a good understanding of their anatomic location. Purpose: To describe the anatomy of the ATFL and CFL ligaments quantitatively and qualitatively and explore the relationship of some morphological parameters. Study Design: Descriptive laboratory study. Methods: A total of 66 adult ankle specimens were analyzed for ATFL band type, origin, length, width, thickness, and angle between the ATFL and CFL, and 73 adult ankle specimens were used for measuring the origin of the CFL. The coefficient of variation was used to describe and compare the respective variability of angle, length, width, and thickness. The origin of the ATFL was labeled as point A, and the leading edge of the CFL intersection with the articular surface of the calcaneus was considered point B. Results: The ATFL had a variable number of bands. A high degree of variability (coefficient of variation >0.2) was seen for most morphological measurements of the ATFL. In addition, the length of distance AB also varied. The CFL originated at the tip of the fibula in only 9% of specimens. It was found more commonly at the anterior border of the lateral malleolus (4.94 ± 1.70 mm from the tip). The angle between the ATFL and CFL was consistent at 100° to 105º. Conclusion: A fair amount of variability of ATFL length, width, and thickness were found in our study, with less variability in the ATFL-CFL angle. Most CFLs attached anterior to the tip of the fibula. Clinical Relevance: Providing relevant anatomic data of ATFL and CFL is important in ensuring proper surgical treatment of ankle joint injuries.

Isolated partial tear of extensor digitorum longus tendon with overlying muscle herniation in acute ankle sports injury: role of high resolution musculoskeletal ultrasound

Lateral Ankle sprain is a common sports-related trauma with the mechanism of injury ranging from inversion to plantar flexion. These injuries commonly affect the ligaments but can also affect the associated soft tissue structures like the eversion muscles and tendons. Prompt and accurate diagnosis of such injuries is warranted so as to ensure early return to play and prevent long-term complications. Lateral ankle sprain injuries in sports may not always be associated with ligament injuries. We report a never before reported case of lateral ankle sprain injury in a soccer player with the unusual finding of isolated partial tear of Extensor digitorum longus muscle and its fascia leading to myo-fascial herniation. The lateral ankle ligaments were intact. The diagnosis was clinched on a high-frequency ultrasound scan supported by dynamic maneuvers which in fact proved to be superior to MRI as the latter failed to demonstrate the myo-fascial herniation in our case. We therefore propose that real-time ultrasound scanning with dynamic maneuvers should be the first line of investigation to assess sports injuries in anatomically complex joints like the ankle.

Strain patterns in normal anterior talofibular and calcaneofibular ligaments and after anatomical reconstruction using gracilis tendon grafts: A cadaver study

BackgroundInversion sprains of the lateral ankle ligaments often result in symptomatic lateral ankle instability, and some patients need lateral reconstruction surgeries to reduce pain, improve function, and prevent subsequent injuries. Although anatomically reconstructed ligaments should behave in a biomechanically normal manner, previous studies have not measured the strain patterns of the anterior talofibular (ATFL) and calcaneofibular ligaments (CFL) after anatomical reconstruction. This study aimed to measure the strain patterns of normal and reconstructed ATFL and CFLs using a miniaturization ligament performance probe (MLPP) system.MethodsThe MLPP was sutured into the ligamentous bands of the ATFLs and CTLs of three fresh-frozen, lower extremity, cadaveric specimens. Each ankle was manually moved from 15° dorsiflexion to 30° plantar flexion, and a 1.2-N m force was applied to the ankle and subtalar joint complex.ResultsThe normal and reconstructed ATFLs exhibited maximal strain (100) during supination in three-dimensional motion. Although the normal ATFLs were not strained during pronation, the reconstructed ATFLs demonstrated relative strain values of 16–36. During axial motion, the normal ATFLs began to gradually tense at 0° plantarflexion, with the strain increasing, as the plantarflexion angle increased, to a maximal value (100) at 30° plantarflexion; the reconstructed ATFLs showed similar strain patterns. The normal CFLs exhibited maximum strain (100) during plantarflexion-abduction and relative strain measurements of 30–52 during dorsiflexion in three-dimensional motion. The reconstructed CFLs exhibited the most strain during dorsiflexion-adduction and demonstrated relative strain measurements of 29–62 during plantarflexion-abduction. During axial motion, the normal CFLs began to gradually tense at 20° plantarflexion and 5° dorsiflexion.ConclusionOur results showed that the strain patterns of reconstructed ATFLs and CFLs are not exactly the same as those in the normal ligaments.

A New Landmark for Positioning the Anatomical Insertions of Lateral Ankle Ligaments under Arthroscopy: A Preliminary Study

Background: Several landmarks are used to ascertain the insertions of lateral ankle ligaments, however, few could be discerned under arthroscopy. The objective of this study was to assess the feasibility and reliability of labeling the anterior process of fibular cartilage surface (FCAP) under arthroscopy, and to compare the distances from the new or conventional landmark to the ligament insertion.Methods: Twenty paired ankles from ten Chinese cadavers were included. A senior and a junior surgeon randomly performed the arthroscopic FCAP marking procedures for the paired ankles of a single cadaver using a Kirchner wire. The distance and direction from the anatomical FCAP' to the marked FCAP were recorded after open dissection. Reliability analysis were calculated using the intraclass correlation coefficient (ICC) and independent sample t test. Moreover, the distance from the upper landmarks (anterior fibular tubercle or FCAP) to the anterior talofibular ligament (ATFL) insertion center (distance “a” or “c”), and from the ATFL to calcaneofibular ligament (CFL) footprint center was measured at the anterolateral side (distance “b”) and lateral groove (distance “d”), respectively.Results: The FCAP was located 1.23±0.29 (range, 0.77–1.67) mm) and 1.52±0.41 (range, 0.92–2.03) mm from the anatomical FCAP' in the senior and junior surgeons’ operations, respectively, which showed no significant difference between the two groups (t=-1.773, P=0.093). And the calculated ICC was 0.767 (P=0.003). The average distance “a” was 19.03±1.47 (range, 16.29–21.3) mm, significantly longer than distance “c”, 15.98±0.97 (range, 14.48–18.02) mm (t=-7.72, P<0.001). However, the distance “b” (7.43±0.54 mm; range, 6.47–8.47) and distance “d” (7.78±0.67 mm; range, 6.42–9.03) showed no statistical difference (t=1.8, P=0.08).Conclusions: The FCAP may be a useful landmark that can be utilized to ascertain anatomical insertions of lateral ankle ligaments under arthroscopy. The measured distances from the landmark to the ligament footprint center could provide spatial information that assist in endoscopic anatomical repair or reconstruction.

Ultrasound shear wave elastography of the anterior talofibular and calcaneofibular ligaments in healthy subjects

Aim of study: Most sprained lateral ankle ligaments heal uneventfully, but in some cases the ligament’s elastic function is not restored, leading to chronic ankle instability. Ultrasound shear wave elastography can be used to quantify the elasticity of musculoskeletal soft tissues; it may serve as a test of ankle ligament function during healing to potentially help differentiate normal from ineffective healing. The purpose of this study was to determine baseline shear wave velocity values for the lateral ankle ligaments in healthy male subjects, and to assess inter-observer reliability. Material and methods: Forty-six ankles in 23 healthy male subjects aged 20–40 years underwent shear wave elastography of the lateral ankle ligaments performed by two musculoskeletal radiologists. Each ligament was evaluated three times with the ankle relaxed by both examiners, and under stress by a single examiner. Mean shear wave velocity values were compared for each ligament by each examiner. Inter-observer agreement was evaluated. Results: The mean shear wave velocity at rest for the anterior talofibular ligament was 2.09 ± 0.3 (range 1.41–3.17); and for the calcaneofibular ligament 1.99 ± 0.36 (range 1.29–2.88). Good inter-observer agreement was found for the anterior talofibular ligament and calcaneofibular ligament shear wave velocity measurements with the ankle in resting position. There was a significant difference in mean shear wave velocities between rest and stressed conditions for both anterior talofibular ligament (2.09 m/s vs 3.21 m/s; p <0.001) and calcaneofibular ligament (1.99 m/s vs 3.42 m/s; p <0.0001). Conclusion: Shear wave elastography shows promise as a reproducible method to quantify ankle ligament stiffness. This study reveals that shear waves velocities of the normal lateral ankle ligaments increased with applied stress compared to the resting state.

Chronic lateral ankle instability: a current concepts review

ABSTRACT Injuries to the lateral ankle ligaments are quite common, with a reported incidence of up to 22% of all sports injuries, and 85% of all ankle sprains. Most of these are effectively managed using nonoperative measures in the acute setting. Approximately 20% of patients will, however, develop chronic lateral ankle instability (CLAI). Although the anatomy and biomechanics are well documented, more recently, the concepts of the lateral talofibular calcaneal ligament (LTFCL) and microinstability have been described. For those who develop CLAI, a full assessment is mandatory to not only search for correctable risk factors (malalignment), but also to differentiate between functional and mechanical instability. Associated injuries need to be excluded, such as osteochondral lesions of the talus. Rotational ankle instability is a new concept that needs to be considered. Patients who present with CLAI are initially managed conservatively in the form of functional rehabilitation. This management is especially effective in patients with functional instability. Surgery is generally indicated after failed conservative management in patients with objective mechanical instability. The elite athlete is a relative indication to performing surgery early. The choice of surgical procedure is made on an individualised basis, although open anatomical procedures remain the gold standard. Non-anatomical procedures are no longer recommended. Newer minimally invasive and endoscopic techniques show promise in experienced hands but there is only limited evidence to support its use at present. The use of a suture tape as an augment is reserved for specific indications and should not be used routinely. Level of evidence: Level 5 Keywords: chronic lateral ankle instability, ATFL, CFL, functional rehabilitation, Broström, surgical procedures for lateral ankle ligaments