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Ankle sprain is the most common injury in athletic populations. Ligament and tendon pathologies of the ankle are common, ranging from traumatic injuries to degeneration leading to chronic pain and acquired foot deformities. MRI is the imaging modality of choice to evaluate tendon and ligament pathology of the ankle, specifically derangements of tendons and ligaments. 3-T MRI offers improved imaging characteristics relative to 1.5-T MRI, allowing for better delineation of anatomic detail and pathology. This article provides a review of the anatomy and common pathologies of the ankle ligaments and tendons using high-resolution 3-T MRI.

Purpose Awideinter-individualvariabilityintermsofsize,orientationandinsertionisobservedregardingankleligaments. The aim of this study is to identify and describe the anatomical features of the posterior talocalcaneal ligament (PTCL) observed through the use of magnetic resonance imaging (MRI) of the ankle. Methods The study was retrospectively carried out on 893 ankle MRI’s exams. The exams have all been performed using a 1.5-T (T) MRI. The same scanning protocols and scan planes were carried out in all the exams. The first evaluated param- eter was the recognition of the PTCL. Subsequently, in all those cases where the ligament was present, its features such as insertion sites, length, and thickness were evaluated. Results The PTCL identification was possible in 77 exams (8.6% of the total number). Among these, we were able to iden- tify some variants regarding insertion sites, length, and thickness. The PTCL could be further classified into four categories based on the most common characteristics observed. Conclusions Our study has identified different characteristics of the PTCL that allow us to further understand the charac- teristics of the ligament itself. In conclusion, the need for further studies focused on the biomechanical role of the PTCL in the ankle joint appears mandatory.

Ankle sprains are common injuries involving the lateral ankle ligaments and affect athletes of all levels. Most patients heal uneventfully, but those with symptoms persisting past 3 months should be evaluated for chronic ankle instability and its associated conditions as well as for the presence of varus malalignment. Chronic ankle instability is initially treated nonoperatively, with surgical management reserved for those who have failed to improve after 3 to 6 months of bracing and functional rehabilitation. Anatomic repair using a modification of the Broström procedure is the preferred technique for initial surgery. Anatomic reconstruction with tendon graft should be considered when repair is not possible, as it maintains physiological joint kinematics. Nonanatomic reconstructions are seldom indicated. Arthroscopic repair or reconstruction of the lateral ankle ligaments is a promising new technique with results similar to those of open surgery.

An increased interest in ankle instability has led to description of new concepts such as ankle microinstability or rotational ankle instability and the development of new arthroscopic techniques treating ankle instability. Ankle instability is constantly associated to intraarticular pathologies that contribute to generate pain and dysfunction. Arthroscopy plays an important role in identifying and treating all intraarticular abnormalities including ligament injuries. Despite a few studies are available in literature on arthroscopic treatment of medial collateral ligament injury, an arthroscopic all-inside repair of lateral and medial ankle ligaments has been proposed showing promising clinical results.

The present article describes the ultrasound (US) appearance of ligaments and paraligamentous structures which are not included in standard US imaging of the ankle: the posterior inferior tibiofibular ligament (PITFL), the transverse tibiofibular ligament (TTFL), the posterior talofibular ligament (PTFL), the posterior intermalleolar ligament (PIL), the synovial recess (SR) of the posterior joint and the os trigonum (OT). Two skilled operators examined 15 ankles in 15 healthy volunteers. Correlation between thickness of the main ligaments and body mass index (BMI) was also analyzed. Compound and tissue harmonic imaging (THI) were carried out using 12-, 6–15- and 9-MHz linear probes. Exploration of the posterior ankle ligament complex is accurately described including correct ankle position, echogenicity, shape, direction and thickness. Both operators identified and measured the main ligaments (PITFL, TTFL and PTFL) in all volunteers (Intraclass Correlation Coefficient ranged from 0.8 to 1); both operators also detected SR and OT in 2/15 ankles and posterior intermalleolar ligament (PIL) in 5/15 ankles. Pearson’s test showed a significant correlation (

The anterior talofibular ligament and the calcaneofibular ligament are the most commonly injured ankle ligaments. This study aimed to investigate if the double fascicular anterior talofibular ligament and the calcaneofibular ligament are associated with the presence of interconnections between those two ligaments and connections with non-ligamentous structures. A retrospective re-evaluation of 198 magnetic resonance imaging examinations of the ankle joint was conducted. The correlation between the double fascicular anterior talofibular ligament and calcaneofibular ligament and connections with the superior peroneal retinaculum, the peroneal tendon sheath, the tibiofibular ligaments, and the inferior extensor retinaculum was studied. The relationships between the anterior talofibular ligament’s and the calcaneofibular ligament’s diameters with the presence of connections were investigated. Most of the connections were visible in a group of double fascicular ligaments. Most often, one was between the anterior talofibular ligament and calcaneofibular ligament (74.7%). Statistically significant differences between groups of single and double fascicular ligaments were visible in groups of connections between the anterior talofibular ligament and the peroneal tendon sheath (p p p p p p p p

Purpose: The purpose of this study was to investigate if the calcaneofibular ligament (CFL) presents morphologic variants and measure the morphometrics of the ligament and its footprints Methods: An anatomical study of 47 fresh-frozen below-the-knee ankle specimens was performed. Lateral ankle structures were dissected to expose the CFL. Overdissection was avoided to not modify the native morphology. The morphology (number and orientation of CFL bundles) and measurements of CFL insertions were recorded with ankle secured in neutral position. Results: Four distinct morphological-oriented shapes of the CFL were observed. These included single bundle, Y-shape double bundle, V-shape double bundle, and associated with the lateral talocalcaneal ligament. The most frequent CFL morphology observed was the single bundle and the Y-shape double bundle, present in 21 (44.7%) and 13 (27.7%) ankles. The V-shape double bundle and the CFL double bundle associated with the lateral talocalcaneal ligaments were less common, appearing only in eight (17.0%) and five (10.6%) ankles. The CFL length was higher in single bundle and Y-shaped double bundle CFL variants, about 30 mm each. Footprint morphometrics were heterogenous amongst the different CFL variants. Conclusion: The CFL presents four distinct morphological-oriented shapes. The double bundle, V-shaped and Y-shaped CFL variants are uncommon and poorly reported in the literature. Their relation to the lateral talocalcaneal ligament and the inferior fascicle of the anterior talofibular ligament requires further research. The CFL morphology provides detailed knowledge of CFL anatomy that can improve diagnostic procedures. Furthermore, this information can fine-tune graft selection and sizing and allow a more precise anatomic placement during surgical reconstruction.

Background: Ankle sprains are the most common musculoskeletal injury in the United States. Chronic lateral ankle instability can ultimately require operative intervention to decrease pain and restore stability to the ankle joint. There are no anatomic studies investigating the vascular supply to the lateral ankle ligamentous complex. Purpose: To define the vascular anatomy of the lateral ligament complex of the ankle. Study Design: Descriptive laboratory study. Methods: Thirty pairs of cadaveric specimens (60 total legs) were amputated below the knee. India ink, followed by Ward blue latex, was injected into the peroneal, anterior tibial, and posterior tibial arteries to identify the vascular supply of the lateral ligaments of the ankle. Chemical debridement was performed with 8.0% sodium hypochlorite to remove the soft tissues, leaving casts of the vascular anatomy intact. The vascular supply to the lateral ligament complex was then evaluated and recorded. Results: The vascular supply to the lateral ankle ligaments was characterized in 56 specimens: 52 (92.9%) had arterial supply with an origin from the perforating anterior branch of the peroneal artery; 51 (91.1%), from the posterior branch of the peroneal artery; 29 (51.8%), from the lateral tarsal branch of the dorsalis pedis; and 12 (21.4%), from the posterior tibial artery. The anterior branch of the peroneal artery was the dominant vascular supply in 39 specimens (69.6%). Conclusion: There are 4 separate sources of extraosseous blood supply to the lateral ligaments of the ankle. In all specimens, the anterior talofibular ligament was supplied by the anterior branch of the peroneal artery and/or the lateral tarsal artery of the dorsalis pedis, while the posterior talofibular ligament was supplied by the posterior branch of the peroneal artery and/or the posterior tibial artery. The calcaneofibular ligament received variable contributions from the anterior and posterior branches of the peroneal artery, with few specimens receiving a contribution from the lateral tarsal or posterior tibial arteries. Clinical Relevance: Understanding the vascular anatomy of the lateral ligament complex is beneficial when considering surgical management and may provide insight into factors that lead to chronic instability.

Objectives To establish patterns of subsequent injury in U18 rugby, to quantify the burden of within season injury recurrence. Design Secondary analysis of prospective data. Setting 28 Schools in Ireland. Participants 825 male rugby players (aged 15–18 years). Main outcome measures Subsequent injuries were classified as: new, local or recurrent (same site and type as index injury). All recurrent injuries were sub-grouped by body part and diagnosis. Burden was based on frequency, days lost and injury proportion ratios. Results A total of 426 injuries were eligible for analysis, of which, 121 were subsequent injuries. The majority of subsequent injuries involved a different body part than their index injury. There were n = 23 cases of within season recurrence. 78% of recurrences occurred within 2 months of return to play. Recurrent injuries comprised 5% of all injuries and their cumulative time loss was 1073 days. Recurrent injury to the ankle ligaments, lumbar muscles and concussions carried the greatest burden. Conclusion The burden of recurrent injury in U18 rugby is lower than in the professional game. However, this population could benefit from targeted secondary prevention efforts including reconsideration of return-to-play protocols for ankle sprain, lumbar muscles and potentially concussion.

Ligament sprains account for a majority of injuries to the foot and ankle complex among athletic populations. The infeasibility of measuring the in situ response and load paths of individual ligaments has precluded a complete characterization of their mechanical behavior via experiment. In the present study a fiber-based modeling approach of in situ ankle ligaments was developed and validated for determining the heterogeneous force-elongation characteristics and the consequent injury patterns. Nine major ankle ligaments were modeled as bundles of discrete elements, corresponding functionally to the structure of collagen fibers. To incorporate the progressive nature of ligamentous injury, the limit strain at the occurrence of fiber failure was described by a distribution function ranging from 12% to 18% along the width of the insertion site. The model was validated by comparing the structural kinetic and kinematic response obtained experimentally and computationally under well-controlled foot rotations. The simulation results replicated the 6 degree-of-freedom bony motion and ligamentous injuries and, by implication, the in situ deformations of the ligaments. Gross stiffness of the whole ligament derived from the fibers was comparable to existing experimental data. The present modeling approach provides a biomechanically realistic, interpretable and computationally efficient way to characterize the in situ ligament slack, sequential and heterogeneous uncrimping of collagen fascicles and failure propagation as the external load is applied. Applications of this model include functional ankle joint mechanics, injury prevention and countermeasure design for athletes.

Background Chronic subtalar instability is a disabling complication after acute ankle sprains. Currently, the literature describing the anatomy of the intrinsic subtalar ligaments is limited and equivocal which causes difficulties in diagnosis and treatment of subtalar instability. The purpose of this study is to assess the anatomical characteristics of the subtalar ligaments and to clarify some points of confusion. Methods In 16 cadaveric feet, the dimensions and locations of the subtalar ankle ligaments were assessed and measured. CT-scans before dissection and after indication of the footprints with radio-opaque paint allowed to generate 3D models and assess the footprint characteristics. Results The cervical ligament (CL) had similar dimensions as the lateral ligaments: anterior length 13.9 ± 1.5 mm, posterior length 18.5 ± 2.9 mm, talar width 13.6 ± 2.2 mm, calcaneal width 15.8 ± 3.7 mm. The anterior capsular ligament (ACaL) and interosseous talocalcaneal ligament (ITCL) were found to be smaller structures with consistent dimensions and locations. Conclusion This study identified consistent characteristics of the intrinsic subtalar ligaments and clarifies the local anatomical situation. The dimensions and footprints of the intrinsic ligaments of the subtalar joint suggest a more important role of the CL and ACaL in the stability of the subtalar joint. The results of this study are relevant to improve diagnostic tools and offer some guidelines when reconstructing the injured ligaments.

Both the plantaris tendon and the peroneus tertius tendon are used as auto- and allogenous graft materials to reconstruct the ankle ligament complex. However, it is unclear to what extent these graft materials resemble the load-deformation behavior of the ankle ligaments. A total of 34 human ankle ligaments and 35 tendons were assessed mechanically deploying a quasi-static tensile testing setup. Tendons were significantly stiffer (median elastic moduli: plantaris tendon = 465.7 MPa, peroneus tertius tendon = 338.5 MPa, medial ligament = 61.4 MPa, lateral ligament = 49.3 MPa; p ≤ 0.035), but more distensible (median strain at maximum force: plantaris tendon = 15.1%, peroneus tertius tendon = 15.3%, medial ligament = 9.3%, lateral ligament = 9.6%; p ≤ 0.008) and mechanically tougher (median ultimate tensile strength: plantaris tendon = 51.0 MPa, peroneus tertius tendon = 40.5 MPa, medial ligament = 4.1 MPa, lateral ligament = 3.5 MPa; p ≤ 0.033) when compared to medial and lateral ankle ligaments. The lateral ligaments of the right ankle were significantly tougher compared to the left side (p = 0.015). The elastic modulus of the medial ligament (r = 0.489, p = 0.045) and the peroneus tertius tendon (r = 0.517, p = 0.014) yielded an age-dependent increase. Both tendons seem biomechanically suitable graft materials to replace the medial and lateral ankle ligaments during physiological loading. The age-dependent increase in tissue elastic properties of the medial vs. lateral ankle ligaments, and differences in ultimate tensile strength between the lateral ligaments left vs. right, may reflect the complex asymmetric loading behavior of both ankle ligaments.

Purpose This study aims to systematically investigate if normal ankle ligaments can be assessed with CT imaging, using MRI as reference standard. Methods 35 patients (mean age: 47 ± 15 years; female n = 19) with combined CT and MRI exams and without MR-morphologic signs of ankle ligamental injury were retrospectively identified. 3 readers independently evaluated the syndesmotic, the lateral and medial ankle ligaments in terms of visibility on a 4-point Likert scale (0–3 points) in multiplanar MDCT images in standard bone kernel reconstructions. In consensus CT-based ligament density and thickness were measured and the appearance was rated for each ligament. Results were compared and validated with corresponding MRI images. Results Almost all ankle ligaments identified in MRI images could be adequately depicted in standard multiplanar bone kernel CT images with a mean visual score of 2.7/3 (± 0.2). Difficulties in CT morphological delineation of ankle ligaments occurred in cases of filiform TNL and TCL and in cases of concurrent soft tissue edema. Interreader agreement for the CT-assessment of ankle ligaments was excellent, with Fleiss Kappa values >0.8. Mean density of evaluated medial and lateral ankle ligaments was 68 ± 2.9 HU, with substantially inter- and intraindividual variations. Thickness measurements and assessment of appearance of ankle ligaments showed a good concordance between CT and MRI. Conclusions Assessment of normal ankle ligaments via standard CT in bone kernel reconstructions is feasible, with some restrictions concerning the medial collateral ligaments and in the presence of soft tissue edema.

Background: Numerous epidemiological studies have emphasized the burden of lateral ankle sprains in youth soccer players. However, no prospective study has identified intrinsic physical and modifiable risk factors for these injuries in this particular population. Although injury prevention programs in soccer incorporate proximal hip and core stability exercises, it is striking that the relationship between impaired proximal hip function and ankle sprains has not yet been prospectively investigated in youth soccer players. Hypothesis: This prospective study aimed to examine whether hip muscle strength is a risk factor for sustaining a lateral ankle sprain in youth soccer players. We hypothesized that decreased hip muscle strength would predispose youth soccer players to an increased risk of lateral ankle sprains. Study Design: Case-control study; Level of evidence, 3. Methods: This study included a total of 133 male youth soccer players (age divisions U11-U17) for analysis. At the beginning of the season, anthropometric characteristics were collected and hip muscle strength was assessed using a handheld dynamometer. Injury registration was performed by the team medical staff during 3 consecutive seasons. A principal-component, multivariate Cox regression analysis was performed to identify potential risk factors for sustaining a lateral ankle sprain. Results: Twelve participants (18% of all reported injuries) sustained a lateral ankle sprain (0.36 per 1000 athletic-exposure hours). After adjustment for body size dependencies and other hip muscle forces, an increase in hip muscle extension force was associated with a significant decrease in the hazard of the injury (hazard ratio, 0.3; 95% confidence interval, 0.1-0.9; P = .028). No other study variable could be identified as a risk factor for lateral ankle sprains. Conclusion: Reduced hip extension muscle strength is an independent risk factor for lateral ankle sprains in male youth soccer players. Other hip muscle strength outcomes were not identified as risk factors. Replication in larger samples with more injured cases is warranted to further ascertain the importance of this risk factor.

The ankle is one of the most common sites of musculoskeletal injury. In a series of 1176 athletic injuries, 14% were found to be injuries of the ankle, and 85% of those were specifically sprains of ankle ligaments [1]. Although many ankle ligaments can be well assessed by an operator trained in ultrasound techniques, evaluation by magnetic resonance imaging (MRI) offers the advantages of a comprehensive and operator-independent examination [2]. In this article, a practical review of MRI of ankle ligaments is presented. The discussion is limited primarily to the ligaments surrounding the tibiotalar joint, particularly the inferior tibiofibular syndesmotic ligaments and the medial and lateral collateral ligaments (Table 1). Because of its close association with the deltoid ligament, the spring ligament is also included. Ligament names are represented by unambiguous abbreviations similar to those appearing in the literature [3e5]. For each ligament, normal anatomy, MRI appearance, and function will be addressed. Next, with regards to the injured ligament, basic mechanisms of injury will be reviewed, taking into consideration differing opinions in the literature that, in some cases, diverge from the classic teachings of Lauge and Hansen [3]. Because ligament injury usually manifests itself in similar ways, such as abnormal signal intensity (intrasubstance or periligamentous) or abnormal morphology (thickening, thinning, discontinuity, absence, irregularity, indistinctness, or heterotopic ossification) [2,4,6], additional imaging clues to injury that are ligamentspecific will be emphasized. Finally, because chronic injury

Objective: Ankle sprains constitute approximately 85% of all ankle injuries and up to 70% of people experience residual symptoms. Whilst the injury to ligaments is well understood the potential role of other foot and ankle structures has not been explored. The objective was to characterise and compare selected ankle structures in participants with and without a history of lateral ankle sprain. \ud Methods: 71 participants were divided into 31 healthy, 20 coper, and 20 chronic ankle instability groups. Ultrasound images of the anterior talofibular and calcaneofibular ligaments, fibularis tendons and muscles, tibialis posterior and Achilles tendon were obtained. Thickness, length, and cross sectional areas were measured and compared between groups. \ud Results: When under tension the anterior talofibular ligament was longer in copers and chronic ankle instability groups compared to healthy participants (p < 0.001 and p = 0.001 respectively). The chronic ankle instability group had the thickest ATFL and CFL among the three groups (p < 0.001). No significant differences (p > 0.05) in tendons and muscles were observed between the three groups. \ud Conclusions: The ultrasound protocol proved reliable and was used to evaluate the length, thickness, and CSA of selected ankle structures. The length of the ATFL and the thickness of the ATFL and CFL were longer and thicker in injured groups compared to healthy.

Background Various imaging techniques have been utilized for the diagnosis of chronic lateral ankle ligament injury. This systemic review will explore the effectiveness of different imaging techniques in diagnosing chronic lateral ankle ligament injury. Methods Relative studies were retrieved after searching 3 databases (MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trails). Eligible studies were summarized. Data were extracted to calculate pooled sensitivity and specificity of magnetic resonance imaging (MRI), ultrasonography (US), stress radiography, and arthrography. Results Fifteen studies met our inclusion and exclusion criteria. A total of 695 participants were included. The pooled sensitivities in diagnosing chronic ATFL injury were 0.83 [0.78, 0.87] for MRI, 0.99 [0.96, 1.00] for US, and 0.81 [0.68, 0.90] for stress radiography. The pooled specificities in diagnosing chronic ATFL injury were 0.79 [0.69, 0.87] for MRI, 0.91 [0.82, 0.97] for US, and 0.92 [0.79, 0.98] for stress radiography. The pooled sensitivities in diagnosing chronic CFL injury were 0.56 [0.46, 0.66] for MRI, 0.94 [0.85, 0.98] for US, and 0.90 [0.73, 0.98] for arthrography. The pooled specificities in diagnosing chronic CFL injury were 0.88 [0.82, 0.93] for MRI, 0.91 [0.80, 0.97] for US, and 0.90 [0.77, 0.97] for arthrography. Conclusion This systematic review with meta-analysis investigated the accuracy of imaging for the diagnosis of chronic lateral ankle ligament injury. Ultrasound manifested high diagnostic accuracy in diagnosing chronic lateral ankle ligament injury. Clinicians should be aware of the limitations of MRI in detecting chronic CFL injuries.

An accurate assessment of ankle ligament kinematics is crucial in understanding the injury mechanisms and can help to improve the treatment of an injured ankle, especially when used in conjunction with robot-assisted therapy. A number of computational models have been developed and validated for assessing the kinematics of ankle ligaments. However, few of them can do real-time assessment to allow for an input into robotic rehabilitation programs.An ankle computational model was proposed and validated to quantify the kinematics of ankle ligaments as the foot moves in real-time. This model consists of three bone segments with three rotational degrees of freedom (DOFs) and 12 ankle ligaments. This model uses inputs for three position variables that can be measured from sensors in many ankle robotic devices that detect postures within the foot-ankle environment and outputs the kinematics of ankle ligaments. Validation of this model in terms of ligament length and strain was conducted by comparing it with published data on cadaver anatomy and magnetic resonance imaging.The model based on ligament lengths and strains is in concurrence with those from the published studies but is sensitive to ligament attachment positions.This ankle computational model has the potential to be used in robot-assisted therapy for real-time assessment of ligament kinematics. The results provide information regarding the quantification of kinematics associated with ankle ligaments related to the disability level and can be used for optimizing the robotic training trajectory.

Background: Various ankle ligaments have different structural composition. The aim of this study was to analyze the morphological structure of ankle ligaments to further understand their function in ankle stability. Methods: One hundred forty ligaments from 10 fresh-frozen cadaver ankle joints were dissected: the calcaneofibular, anterior, and posterior talofibular ligaments; the inferior extensor retinaculum, the talocalcaneal oblique ligament, the canalis tarsi ligament; the deltoid ligament; and the anterior tibiofibular ligament. Hematoxylin-eosin and Elastica van Gieson stains were used for determination of tissue morphology. Results: Three different morphological compositions were identified: dense, mixed, and interlaced compositions. Densely packed ligaments, characterized by parallel bundles of collagen, were primarily seen in the lateral region, the canalis tarsi, and the anterior tibiofibular ligaments. Ligaments with mixed tight and loose parallel bundles of collagenous connective tissue were mainly found in the inferior extensor retinaculum and talocalcaneal oblique ligament. Densely packed and fiber-rich interlacing collagen was primarily seen in the areas of ligament insertion into bone of the deltoid ligament. Conclusions: Ligaments of the lateral region, the canalis tarsi, and the anterior tibiofibular ligaments have tightly packed, parallel collagen bundles and thus can resist high tensile forces. The mixed tight and loose, parallel oriented collagenous connective tissue of the inferior extensor retinaculum and the talocalcaneal oblique ligament support the dynamic positioning of the foot on the ground. The interlacing collagen bundles seen at the insertion of the deltoid ligament suggest that these insertion areas are susceptible to tension in a multitude of directions. Clinical Relevance: The morphology and mechanical properties of ankle ligaments may provide an understanding of their response to the loads to which they are subjected.

sprains remain the single most frequent injury in modern sports. With the growing knowledge on ankle joint disorders, it appears that this injury causes more damage to the ankle joint than was previously assumed. Previously, few papers have investigated the concomitant injuries that may be associated with a “simple lateral ankle sprain”. The editors have selected peer-reviewed articles for this current special edition, which present updated scientific information on the pathologies associated with an ankle sprain. We hope that the reader will be in a position, after reading this edition, to incorporate this information into common daily practice when managing ankle injuries and in this way reduce the morbidity associated with this seemingly innocuous condition. The cornerstone of clinical practice is sound knowledge of surgical anatomy. For this reason, we have decided to republish Golano’s article on the anatomy of the ankle ligaments as the leading paper in this issue with an addendum from one of Golano’s former co-workers, Mik Dalmau Pastor, representing the Barcelona School of Orthopaedic Surgical Anatomy [5]. KSSTA is proud to present a special issue on ankle joint disorders following a lateral ankle sprain. Lateral ankle

Ankle sprains constitute the majority of ankle injuries, and result in pain, limited mobility/exercise and loss of school/work days. Ankle sprains involve at least one of the ankle ligaments and range from a micro tear to complete tear of the ligament or group of ligaments. The most common mechanism of ankle sprains is inversion stress of a plantar-flexed foot, while the most frequently injured ligament is the anterior talofibular ligament. The attending clinician needs to stratify the risk of fracture through history-taking and physical examination, manage the pain, assess long-term complications and provide certification for rest and recovery. The Ottawa ankle rules may be useful. Graduated exercises to maintain the ankle’s range of motion should be started early, after the resolution of initial pain and swelling. The risk of recurrent ankle injuries is often a combination of both mechanical and functional disabilities.

The aim of this work is to provide a computational tool for the mechanical characterization of the hindfoot ligaments. The investigation is performed by a coupled numerical and experimental approach. For this purpose, a numerical model that represents the complex structural configuration of the hindfoot and the typical features of the mechanical behaviour of the ligament tissue is developed. The geometrical analysis of the anatomical site is performed starting from the processing of computed tomography and magnetic resonance images. Accounting for morphometric measurements, the virtual solid model provides an averaged configuration of the hindfoot structure. In order to specify the mechanical behaviour of the ligament tissue, a fibre-reinforced visco-hyperelastic model is adopted. The formulation accounts for the anisotropic configuration, geometric non-linearity, non-linear elasticity and time-dependent phenomena. Numerical analyses are performed to evaluate the biological tissues and structure mechanics with regard to physiological boundary conditions, accounting for dorsiflexion and plantarflexion movements. In order to evaluate the reliability of the numerical model developed, the experimental data are compared with the numerical results. The numerical results are in agreement with the range of values obtained by experimental test confirming the accuracy of the procedure adopted.

Ligament sprains, defined as tearing of bands of fibrous tissues within ligaments, account for a majority of injuries to the foot and ankle complex in field-based sports. External rotation of the foot is considered the primary injury mechanism of syndesmotic ankle sprains with concomitant flexion and inversion/eversion associated with particular patterns of ligament trauma. However, the influence of the magnitude and direction of loading vectors to the ankle on the in situ stress state of the ligaments has not been quantified in the literature. The objective of the present study was to search for the maximum injury tolerance of a human foot with an acceptable subfailure distribution of individual ligaments. We used a previously developed and comprehensively validated foot and ankle model to reproduce a range of combined foot rotation experienced during high-risk sports activities. Biomechanical computational investigation was performed on initial foot rotation from $$20{^{\circ }}$$ of plantar flexion to $$15{^{\circ }}$$ of dorsiflexion, and from $$15{^{\circ }}$$ of inversion to $$15{^{\circ }}$$ of eversion prior to external rotation. Change in initial foot rotation shifted injury initiation among different ligaments and resulted in a wide range of injury tolerances at the structural level (e.g., 36–125 Nm of rotational moment). The observed trend was in agreement with a parallel experimental study that initial plantar flexion decreased the incidence of syndesmotic injury compared to a neutral foot. A mechanism of distributing even loads across ligaments subjected to combined foot rotations was identified. This mechanism is potential to obtain the maximum load-bearing capability of a foot and ankle while minimizing the injury severity of ligaments. Such improved understanding of ligament injuries in athletes is necessary to facilitate injury management by clinicians and countermeasure development by biomechanists.

The aim of this work is to provide a computational tool for the investigation of ankle mechanics under different loading conditions. The attention is focused on the biomechanical role of ankle ligaments that are fundamental for joints stability. A finite element model of the human foot is developed starting from Computed Tomography and Magnetic Resonance Imaging, using particular attention to the definition of ankle ligaments. A refined fiber-reinforced visco-hyperelastic constitutive model is assumed to characterize the mechanical response of ligaments. Numerical analyses that interpret anterior drawer and the talar tilt tests reported in literature are performed. The numerical results are in agreement with the range of values obtained by experimental tests confirming the accuracy of the procedure adopted. The increase of the ankle range of motion after some ligaments rupture is also evaluated, leading to the capability of the numerical models to interpret the damage conditions. The developed computational model provides a tool for the investigation of foot and ankle functionality in terms of stress-strain of the tissues and in terms of ankle motion, considering different types of damage to ankle ligaments.

Background: Treatment of patients with repeated ankle sprains and chronic lateral ankle instability tends to focus on the lateral collateral ligaments. We reviewed records to ascertain the prevalence of abnormalities of the deltoid ligament in this population. Methods: Retrospective review of MR images and surgical reports was performed for all patients during a 3-year period that underwent surgical treatment of chronic ankle instability at a single institution. Forty-seven ankles (46 patients) met inclusion criteria. None had medial ankle pain. Results: On MRI, all patients had anterior talofibular ligament tear, plus injury to one or more additional ligaments. Ninety-one percent had injury of calcaneofibular ligament. Injury to the posterior talofibular ligament was less common (49%). Deltoid ligament injuries were seen in 72% of cases (23% superficial deltoid only, 6% deep deltoid only, 43% both superficial and deep components). Of patients with injury to the superficial deltoid, 32% had an intact deep deltoid ligament. MRI correlated well to surgical findings. Conclusion: Deltoid ligament injuries were common in patients with lateral ankle instability who underwent reconstruction. Level of Evidence: IV, Retrospective Case Series

Background: In the assessment of lateral ankle instability, the anterior drawer test has been found to be inaccurate and the focus on pure anterior translation cannot properly perceive the anterolateral rotatory nature of the talar displacement. In order to address this, the anterolateral drawer test can be done with digital palpation of the talar displacement anterolaterally with a controlled angle of plantarflexion as well as application of the translational force. Materials and Methods: We evaluated the anterolateral drawer test and the original anterior drawer test in 10 fresh below-the-knee specimens using a direct anatomic measurement (DAM) loaded by a Telos stress device as a reference. Specimens were assigned into three groups: intact ligaments, ATFL-cut, and ATFL&CFL-cut. The examiners were blinded with one performing the anterolateral drawer test (E1) while the other performed the original anterior drawer test (E2). Results: Pearson's correlation coefficient indicated a statistically significant linear relationship between DAM/E1 r = 0.931, p < 0.001 but not between DAM/E2 r = 0.519, p = 0.124. Intraclass correlation coefficient show correlation between DAM/E1 and DAM/E2 to be 0.945 ( p < 0.001) and 0.683 ( p = 0.051). When 3 mm or more was used as the threshold to diagnose a lateral ligament rupture, sensitivity and specificity were E1(100%, 100%) and E2(75%, 50%). Conclusion: The anterolateral drawer test showed high accuracy in the determination of lateral ankle instability and in the diagnosis of a ligament rupture. Clinical Relevance: Further investigation regarding the accuracy and reliability of this test in comparison with the original anterior drawer test is warranted in a patient population with ankle instability.

The presence of sensorimotor deficits in patients who have suffered ankle sprains or who have chronic ankle instability has been recognized for several decades; however, a body of research literature has developed that elucidates potential physiologic explanations for these deficits. Alterations in a spectrum of sensorimotor measures make it apparent that conscious perception of afferent somatosensory information, reflex responses, and efferent motor control deficits are present with ankle instability. The specific origin of these deficits local to the ankle ligaments or at the spinal or supraspinal levels of motor control have yet to be fully elucidated. It is clear, however, that both feedback and feedforward mechanisms of motor control are altered with ankle instability.

Ankle sprains are by far the most common injuries treated by sport medicine physicians. Treatment is mainly conservative, but in some cases surgical intervention is required. The aim of the present manuscript is to give an insight into the origins and developments of ankle ligaments reconstructive surgery, underlining the fundamental steps that marked the transition from a mere conservative approach to surgical treatment options. In this historical note, the most illustrious figures who contributed to this particular field of orthopaedic practice are also acknowledged. Level of evidence V.

Background:Secondary surgical repair of ankle ligaments is often indicated in cases of chronic lateral ankle instability. Recently, arthroscopic Broström techniques have been described, but biomechanical information is limited. The purpose of the present study was to analyze the biomechanical properties of an arthroscopic Broström repair and augmented repair with a proximally placed suture anchor. It was hypothesized that the arthroscopic Broström repairs would compare favorably to open techniques and that augmentation would increase the mean repair strength at time zero.Methods:Twenty (10 matched pairs) fresh-frozen foot and ankle cadaveric specimens were obtained. After sectioning of the lateral ankle ligaments, an arthroscopic Broström procedure was performed on each ankle using two 3.0-mm suture anchors with #0 braided polyethylene/polyester multifilament sutures. One specimen from each pair was augmented with a 2.9-mm suture anchor placed 3 cm proximal to the inferior tip of the lateral malleolus. Repairs were isolated and positioned in 20 degrees of inversion and 10 degrees of plantarflexion and loaded to failure using a dynamic tensile testing machine. Maximum load (N), stiffness (N/mm), and displacement at maximum load (mm) were recorded.Results:There were no significant differences between standard arthroscopic repairs and the augmented repairs for mean maximum load and stiffness (154.4 ± 60.3 N, 9.8 ± 2.6 N/mm vs 194.2 ± 157.7 N, 10.5 ± 4.7 N/mm, P = .222, P = .685).Conclusions:Repair augmentation did not confer a significantly higher mean strength or stiffness at time zero.Clinical Relevance:Mean strength and stiffness for the arthroscopic Broström repair compared favorably with previous similarly tested open repair and reconstruction methods, validating the clinical feasibility of an arthroscopic repair. However, augmentation with an additional proximal suture anchor did not significantly strengthen the repair.

The ankle is the most frequently injured major joint in the body, and ankle sprains are frequently encountered in individuals playing football, basketball, and other team sports, in addition to occurring in the general population. Imaging plays a crucial role in the evaluation of ankle ligaments. Magnetic resonance imaging has been proven to provide excellent evaluation of ligaments around the ankle, with the ability to show associated intraarticular abnormalities, joint effusion, and bone marrow edema. Ultrasonography (US) performed with high-resolution broadband linear-array probes has become increasingly important in the assessment of ligaments around the ankle because it is low cost, fast, readily available, and free of ionizing radiation. US can provide a detailed depiction of normal anatomic structures and is effective for evaluating ligament integrity. In addition, US allows the performance of dynamic maneuvers, which may contribute to increased visibility of normal ligaments and improved detection of tears. In this article, the authors describe the US techniques for evaluation of the ankle and midfoot ligaments and include a brief review of the literature related to their basic anatomic structures and US of these structures. Short video clips showing dynamic maneuvers and dynamic real-time US of ankle and midfoot structures and their principal pathologic patterns are included as supplemental material. Use of a standardized imaging technique may help reduce the intrinsic operator dependence of US. Online supplemental material is available for this article.

The biomechanical anatomy of the ankle ligaments continues to be a subject of interest because detailed knowledge of these structures is essential for proper diagnosis and treatment of the injuries affecting them. Lesions to the ankle ligaments are one of the most common sports injuries and the origin of soft tissue impingement syndrome. Together with the ligaments of the tibiofibular syndesmosis, two large ligamentous complexes are the main static stabilizers of the ankle joint: the lateral collateral ligament and the medial collateral (or deltoid) ligament. This article provides an anatomic description of the various ligaments of the ankle joint, with particular emphasis on specific anatomic details that are often omitted or little known and that have considerable clinical interest because of their involvement in soft tissue syndrome.

To determine which combination of landing protocol and analysis technique would be the most effective at detecting differences in dynamic stability between healthy subjects and subjects with functional ankle instability (FAI).Fifty-eight subjects participated in this investigation: 29 healthy individuals and 29 individuals with FAI. Subjects were assessed during a single test session for time to stabilization (TTS) in the anterior/posterior, medial/lateral, and vertical directions from two protocols: a step down and jump protocol. The step down protocol started with each subject atop a 20-cm-high platform, and the jump protocol started with subjects in a standing position 70 cm from the center of a force plate and required each subject to jump off both legs and touch a designated marker placed at a position equivalent to 50% of the subject's maximum vertical leap. TTS scores in the anterior/posterior, medial/lateral, and vertical direction were compared between group, protocol, and type of analysis.A significant protocol by analysis by group interaction (F(1,56) = 6.9, P = 0.011) was observed for anterior/posterior TTS. Likewise, protocol by group (F(1,56) = 4.4, P = 0.042) and protocol by analysis (F(1,56) = 14.1, P0.001) interactions were also noted in anterior/posterior TTS. The jump protocol (2381.7 +/- 36.5 ms) produced significantly greater TTS scores in the vertical direction than the step protocol (1533.5 +/- 71.8 ms), whereas the unbounded third order polynomial (UTOP) method (2554.4 +/- 68.7 ms) produced significant greater TTS scores as compared with the sequential estimation (SE) method (1360.8 +/- 52.1 ms).The jump protocol and UTOP method of analysis are the most effective TTS combination in detecting differences between healthy and FAI groups.

The objectives of our study were to determine the accuracy of new MRI criteria in detecting tears of the superficial deltoid ligament of the ankle, the accuracy of established criteria for detecting deep deltoid ligament tears, the most common location of super-ficial deltoid ligament tears, and the frequency of other injuries associated with deltoid tears.A chart review yielded 89 cases over a 3-year interval in which ankle MRI was followed by open or arthroscopic surgery and the surgical report described findings in the deltoid ligament. One case was excluded because the MRI study was technically inadequate. MRI and surgical reports were then compared for the presence and location of deltoid ligament tears.MRI findings of focal detachment of the superficial deltoid origin or detachment of the fascial sleeve of the medial malleolus yielded a sensitivity for superficial deltoid ligament tears of 83.3% (45/54) and specificity of 93.9% (31/33). Eight of nine prospectively missed tears were visible on retrospective review. All superficial deltoid tears involved the origin of the ligament from the medial malleolus, and six involved mid or distal bundles of the superficial deltoid as well. MRI findings of discontinuity or nonvisualization of discrete fibers yielded a sensitivity for deep deltoid ligament tears of 96.3% (26/27) and specificity of 97.9% (46/47).MRI has a high accuracy for deltoid ligament tears in consecutive cases prospectively evaluated by musculoskeletal radiologists. The location of superficial deltoid ligament tears differed in our series from findings previously reported in the imaging literature.

Since inversion ankle sprain (IAS) damages ankle ligaments and induces changes in their viscoelastic properties, evaluating these properties may provide an approach to assess injury. The study purposes were to investigate how the viscoelastic properties of the ankle ligament complex can be used to quantitatively assess IAS, and to investigate the usefulness of the stretched exponential function to analyze the relaxation behavior of the ankle ligament complex. Fifteen participants with unilateral IAS and 15 controls were included. The relaxation behavior of each ankle was measured by an instrumented anterior drawer test, and was then curvefitted by the stretched exponential function. By a modeling approach, both parameters of the function were found to be associated with the viscous response. Statistical analysis was performed to determine differences in these two parameters between sprained and uninjured ankles. It was found that sprained ankles exhibited significantly lower viscous response than uninjured ankles. No significant difference was found among uninjured ankles. In conclusion, by using the viscoelastic properties, sprained ankles were successfully differentiated from uninjured ankles. In clinical application, this method could be a diagnostic tool for quantitative assessment of IAS injury. The stretched exponential function was a useful model to analyze the relaxation behavior.

This study was aimed at the definition of a constitutive formulation of ankle ligaments and of a procedure for the constitutive parameters evaluation, for the biomechanical analysis by means of numerical models. To interpret the typical features of ligaments mechanical response, as anisotropic configuration, geometric non-linearity, non-linear elasticity and time-dependent behaviour, a specific fibre-reinforced visco-hyperelastic model is provided. The identification of constitutive parameters is performed by a stochastic-deterministic procedure that minimises the discrepancy between experimental and computational results. A preliminary evaluation of parameters is performed by analytical models in order to define reference values. Afterwards, solid models are developed to consider the complex histo-morphometric configuration of samples as a basis for the definition of numerical models. The results obtained are adopted for upgrading parameter values by comparison with specific mechanical tests. Assuming the new parameters set, the final numerical results are compared with the overall set of experimental data, to assess the reliability and efficacy of the analysis developed for the interpretation of the mechanical response of ankle ligaments.

Most acute ankle injuries involve the lateral ligament complex. There are several other structures that can be injured during acute ankle trauma and therefore can be responsible for the patient's acute presentation or for continuing pain. Some of these injuries are less common than others and thus can be more frequently missed during the initial patient presentation. Continued pain and disability following acute ankle trauma that is not responding to routine conservative treatment should alert the clinician and the radiologist for the possibility of injuries other than the common lateral ligament sprain. In this article we describe those injuries that are often overlooked during acute ankle assessment. These include the less common ankle ligaments injuries, fractures, and tendon-related abnormalities.

OBJECTIVE:: Ankle sprains are the most common injury in the active population. With high reinjury rates and complaints of the ankle "giving way," it has been suggested that laxity of ankle ligaments increases with repeated sprains. The objective of this study was to determine if a relationship exists between ligament laxity and the number of ankle sprains. DESIGN:: Cross-sectional study. SETTING:: Biomechanics laboratory. PARTICIPANTS:: A total of 203 Division I collegiate athletes (84 women; 119 men; age, 18.5 ± 1.1 years; height, 178.5 ± 10.8 cm; mass, 79.8 ± 18.7 kg) participated in the study. INTERVENTION:: Each participant reported the number of previous sprains on each ankle. Ligament laxity was measured using an instrumented ankle arthrometer. MAIN OUTCOME MEASURES:: Measurements for anterior displacement (AD), inversion (IV), and eversion (EV) rotation of the ankle were obtained using an instrumented ankle arthrometer. RESULTS:: There was no relationship between ligament laxity and the number of ankle sprains in either direction (AD, P = 0.86; IV, P = 0.64; EV, P = 0.81). In addition, comparing ligament laxity between previously sprained ankles and ankles that have never been sprained resulted in no differences in the direction of movement (AD, P = 0.98; IV, P = 0.96; EV, P = 0.67). CONCLUSIONS:: Despite anecdotal evidence suggesting repeated ankle sprains increase ligament laxity, this report involving a large data set and a reliable measurement analysis found no relationship between the two. The results of this study make it necessary to rethink the causes of ligament laxity. Therefore, further research is necessary to understand the causes of "giving way" of the ankle and their role in repeated ankle sprains. Language: en

Orthotic devices have been shown to successfully modify selected aspects of lower extremity mechanics and enhance foot stability during the support phase of running. It was hypothesized that orthotic intervention would relieve excessive strain on the ankle ligaments and reduce postural sway, especially in subjects with acute ankle sprains. The primary purpose of this study was to determine if orthotics would reduce postural sway in injured and uninjured subjects. Thirteen subjects with acute inversion ankle sprains and 12 uninjured subjects were assessed for postural sway on the Balance System under two treatment conditions (orthotic and nonorthotic) and four platform movements. A three-factor repeated measures analysis of variance revealed a significant group x treatment interaction, suggesting that postural sway with orthotic intervention improved significantly more in injured subjects than in uninjured subjects. A significant platform movement x treatment interaction, furthermore, revealed that postural sway for the four movement conditions was dependent upon treatment (orthotic vs. no orthotic). Tukey post hoc analysis revealed that orthotic intervention significantly reduced postural sway when the platform moved in the medial/lateral plane and inversion/eversion plane. This research suggests that custom-fit orthotics may restrict undesirable motion at the foot and ankle and enhance joint mechanoreceptors to detect perturbations and provide structural support for detecting and controlling postural sway in ankle-injured subjects.

The purpose of this study was to clarify the role of the ankle ligaments in controlling the tibial rotation for different foot positions. A 6 degrees of freedom device was constructed for in vitro simulation of this movement transfer during the support phase of gait. Tibia rotation angle was measured for different foot positions and vertical loads, while the ligament integrity was modified. Data were collected from eight legs of four different cadavers. The results showed that vertical loading is unimportant to influence tibial rotation, while the lateral ankle ligaments have significant influence, especially during eversion. It was concluded that chronic partial or total lateral ankle instability may contribute to knee and foot injuries through abnormal tibial rotation.

Background: Total ankle replacement has become a valuable treatment option for end-stage osteoarthritis. The most recent generation of implants comprises a second interface between the polyethylene insert and the tibial prosthetic component. This may permit a better adaptation of position between the implant components and thereby prevent unphysiological loading of ankle ligaments and reduce polyethylene wear. To date, no available data have evaluated whether the relative position of talar and tibial implant components change over time. Materials and Methods: We assessed the radiographs of 368 ankles that underwent primary arthroplasty with a HINTEGRA® (Newdeal SA, Lyon, France / Integra, Plainsboro, NJ) ankle to determine the spatial relationship between talar and tibial components at the time of surgery and during followup. The mean time to final followup was 51.2 months (range 11 to 98). We analyzed the anteroposterior offset as the distance between the center of the tibiotalar joint and the longitudinal axis of the tibia. Results: The mean anteroposterior offset ratio was 0.0 ± 0.06 (range −0.21 to 0.16), and it remained constant over time. Conclusion: Our data suggest that the latest three-component prosthesis functions similar to the two-component prosthesis, but we believe with an added advantage of allowing an individualized position of the polyethylene insert in response to the individual soft tissue load due to different ankle joint configurations. Level of Evidence: IV, Case Series

Thirteen patients with clinically diagnosed sprained ankles underwent magnetic resonance (MR) imaging. Five of these cases are presented to illustrate the potential of MR imaging to enable identification of both primary and associated ligament injury sites, grading of the severity of the injuries, and visualization of the associated findings of tendon sheath and joint effusion. The appropriate combination of foot position and imaging plane is essential to achieve full-length visualization of each ligament. Two patients demonstrated findings compatible with total gross disruption of the anterior fibulotalar ligament; two, with injury to the fibulocalcaneal ligament with effusion of the overlying peroneus tendon sheath; and one, with thinning, lengthening, and fibrotic changes involving the anterior fibulotalar ligament. MR imaging can provide a noninvasive means to evaluate the site and severity of ankle ligament injuries (a) in acute ankle injuries that demonstrate significant instability, (b) in stable acute injuries involving athletes or litigation, or (c) in patients with repeated injuries or instability in whom surgery is contemplated.

OBJECTIVE. The objective of our study was to provide a pictorial survey of MR images of ankle ligaments in various conditions from intact to disrupted.CONCLUSION. MR images of ankle ligaments from a sample of patients with ankle pain or injury are presented and reviewed.

Magnetic resonance imaging is an excellent technique for imaging the tendons and the ligaments of the ankle. Owing to the advantage of detailed demonstration of soft-tissue structures and capability for multiplanar demonstration of the ankle ligaments and tendons, MRI has been increasingly used in the evaluation of the ligamentous and the tendon injuries of the ankle. Knowledge of normal anatomy and of MRI appearances are essential to recognize pathological appearances. In this pictorial essay, the first of a three part series, we review the normal MRI appearances of the ankle tendons and ligaments. The anterior, lateral and medial tendon groups, the Achilles tendon and the lateral, the syndesmotic and the medial ligament groups are described and illustrated. Anatomy of the sinus tarsi is also described. Tendon and ligament pathology will be illustrated in the second part of the series, and imaging approach to ankle injuries will be outlined in the final part of this series.

This project measured pre-season balance ability and determined its relationship to knee and ankle ligament injuries during the season for professional Australian footballers. The balance test involved the players stepping onto a foam balance mat on top of a force plate and maintaining single limb balance. Throughout the playing season, injuries were monitored. The results from two hundred and ten players participating in this project were analysed. During the 2003 season, 8 % (17 out of 210) sustained a knee ligament injury and 10 % (21 out of 210) sustained an ankle ligament injury. Multivariate analysis revealed that pre-season balance ability was a significant independent predictor of ankle ligament injury. Players with low balance ability had at least twice as many ankle ligaments injuries as those with average or good balance ability. Balance ability was not a significant predictor of knee ligament injuries. The height of the players was the only significant independent predictor of knee ligament injuries. Low pre-season balance ability was associated with an increased risk of ankle ligament injury. A modifiable injury risk factor has been identified. Research is now required to determine the optimal training regime to enhance balance ability and whether this translates to a reduction in the incidence of ankle injuries.

Background: Development of reconstructive operative procedures to restore normal ankle kinematics after injury requires an understanding of the biomechanics of the ankle during gait. The contribution of the peri-ankle ligaments to ankle motion control is not yet well understood. Knowledge of the tensile engagement of the peri-ankle ligaments during stance phase is necessary to achieve physiologic motion patterns. Methods: Eleven fresh-frozen cadaver ankles were subjected to a dynamic loading sequence simulating the stance phase of normal level gait. Simultaneously, ligament strain was continuously monitored in the anterior talofibular, calcaneofibular, and posterior talofibular ligaments, as well as in the anterior, middle, and posterior superficial deltoid ligaments. Eight of these specimens underwent further quasi-static range-of-motion testing, where ligament tension recruitment was assessed at 30 degrees plantarflexion and 30 degrees dorsiflexion. Results: In the dynamic loading tests, none of the ligaments monitored showed a reproducible strain pattern indicating a role in ankle stabilization. However, in the extended range-of-motion tests, most ligaments were taut in plantarflexion or dorsiflexion. Conclusions: A consistent combination of individual ligament strain patterns that principally control ankle motion was not identified; none of the ligaments studied were reproducibly recruited to be a primary stabilizing structure. The peri-ankle ligaments are likely to be secondary restraining structures that serve to resist motion to avoid extreme positions. Stance phase ankle motion appears to be primarily controlled by articular congruity, not by peri-ankle ligament tension.

Background: The aim of this study was to examine the mechanical behavior of human ankle ligaments at low forces. Predominantly, ankle ligaments have been studied under the auspices of ligament injury. While the mechanical properties of a ligament when tested to failure provide a basis for comparisons, the loads and displacement do not reflect normal physiologic loading. Methods: Eight fresh-frozen ankles (mean age 65) were dissected to expose the ligaments surrounding the talocrural joint. Eight ankle ligaments were studied and included: medially-anterior tibiotalar (ATTL), posterior tibiotalar (PTTL), tibiocalcaneal (TCL); laterally – anterior tibiofibular (ATiFL), posterior tibiofibular (PTiFL), anterior talofibular (ATFL), posterior talofibular (PTFL), and calcaneofibular (CFL). Stress relaxation tests were carried out at 30% and 10% strain. The peak load and area under the curve were assessed for all experiments. Results: Significant differences were found for the average peak loads of the elastic response between 30% and 10% strain for each ligament ( p .05). The anterior talofibular ligament was found to possess similar relaxation results to the medial ligaments. The calcaneofibular ligament relaxed up to 10% more compared to the anterior talofibular for the same relaxation period. The mechanical testing was performed in uniaxial tension and did not consider off-axis loading that may occur in vivo during ankle motion. Conclusions: The stress relaxation experiments revealed all ligaments to relax even when loaded to less than 5 N, reflecting the viscoelastic nature of ligaments. The stress relaxation results show that the anterior talofibular ligament does not relax to the same extent as the other lateral ligaments. Examining the properties of human ankle ligaments at low loads has revealed some new findings. Clinical Relevance: This study highlights the need to understand the synergistic effects of the ligaments. This is important for reconstruction and arthroplasty procedures.

Background. Although most would agree that stress radiography is an important research tool to evaluate the integrity of the ankle ligaments in studies of chronic ankle instability, there is little agreement with regard to the best technique to make these measurements. The primary objective of this study was to establish the most reliable method for measuring anterior displacement of the talus relative to the tibia using stress radiographs of the ankle. This information is necessary to standardize radiographic evaluation of injured ankles and for biomechanical studies of the ankle joint, but has never been investigated. Methods. This study examined the reliability of four available methods by measuring the intra-observer repeatability and inter-observer reproducibility of three different investigators. Lateral radiographs were obtained while the ankle was supported in the Telos device with the joint unloaded, and then with a 150 N anterior directed load applied to the calcaneus. At two separate time intervals, the radiographs were read by three different observers using four measurement techniques. For each technique, the measurement of the unloaded ankle was subtracted from the loaded ankle to obtain anterior talar translation. Findings. The method that measured the shortest distance between the posterior lip of the distal tibia and the talar dome (designated Method I in the current series) was significantly more reproducible between readers and within readers across repeated measurements than the other methods tested. Interpretation. Based on the findings from this study, it can be concluded that measurement of the distance between the posterior lip of the distal tibia and the talar dome is the method of choice to characterize the position of the talus relative to the tibia in stress radiography. In order to standardize the radiographic evaluation of ankle injuries, this method should be the one employed to measure anterior talar translation.

Injuries to the lateral ligament complex of the ankle are common problems in acute care practice. We believe that a well-developed knowledge of the anatomy provides a foundation for understanding the basic mechanism of injury, diagnosis, and treatment, especially surgical treatment, of lateral collateral ankle ligament injury. To address this issue we performed this review with regard to the anatomy of the lateral collateral ankle ligaments. Clin. Anat. 21:619–626, 2008. © 2008 Wiley-Liss, Inc.

Because of their size and superficial location the ankle tendons can be well evaluated with ultrasound (US). The excellent definition of the modern high frequency probes allows us to consider US the technique of first choice in their assessment. Basic US appearances correlate well with the MRI findings. Since US can diagnose most tendon disorders including tendinopathies, tears, dislocations and enthesopathies MRI is less often utilized. US can easily depict the main ankle ligaments. The basic US appearance of ligament tears is well known. US can be considered an inexpensive and accurate technique in the evaluation of ankle sprains.