Reliability and Validity of Magnetic Resonance Imaging for the Evaluation of the Anterior Talofibular Ligament in Patients Undergoing Ankle Arthroscopy

Diagnostic value of ultrasonography for injury of anterior talofibular ligament and anterior inferior tibiofibular ligament distal fascicle in patients with ankle fractures

OBJECTIVES

To explore the diagnostic value of ultrasonography for injuries of anterior talofibular ligament (ATFL) and anterior inferior tibiofibular ligament distal fascicle (ATiFL-DF) in patients with ankle fractures.

METHODS

Clinical data of 51 patients with ankle fractures who were clinically suspected of ligament injuries and underwent ankle ultrasonography examination and arthroscopy in Sir Run Run Shaw Hospital, Zhejiang University School of Medicine from April 2019 to March 2023 were retrospectively analyzed. Using arthroscopic results as the gold standard, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ultrasonography in diagnosing ATFL and ATiFL-DF injuries were evaluated, and Kappa consistency test was performed.

RESULTS

The sensitivity and specificity of ultrasonography in diagnosis of ATFL injury were 100.0% and 92.3%, with the PPV of 92.6% and NPV of 100.0%. Ultrasonography findings exhibited excellent concordance with arthroscopic results (kappa=0.849). The sensitivity and specificity of ultrasonography in diagnosis of ATiFL-DF injury was 86.7% and 33.3%, with the PPV of 90.7% and NPV of 25.0%. However, the consistency between ultrasonography and arthroscopic results was poor (kappa=0.168).

CONCLUSIONS

Ultrasonography is reliable in assessing injuries of ATFL in patients with ankle fractures, but its specificity in diagnosing ATiFL-DF is poor. Therefore, ankle arthroscopy remains necessary for ankle fracture patients with negative findings of ATiFL-DF in ultrasonography.

The Distal Fascicle of the Anterior Inferior Tibiofibular Ligament: A Potential Landmark for Lateral Ankle Ligament Reconstruction

BACKGROUND

A reliable landmark and precise distances from the ligament attachments are needed for lateral ankle stabilization surgery. The distal fascicle of the anterior inferior tibiofibular ligament (AITFL) has been used to locate the anterior talofibular ligament (ATFL) or calcaneofibular ligament (CFL) centers on the fibula. However, there is no anatomic study to validate the distal fascicle of the AITFL as a landmark of lateral ankle ligament stabilization, and more importantly, the exact distances from the ATFL or CFL attachments to the distal fascicle of the AITFL are unknown.

METHODS

Sixteen frozen cadaveric specimens (8 paired specimens) with no previous history of ankle injury were used in this study. Whether the distal fascicle of AITFL was present in each specimen was confirmed. Then, the distances from the most distal insertion of the AITFL's distal fascicle to the footprint centers of the ATFL and CFL on the fibula were measured. All measurements were performed by 2 observers, and the intraobserver and interobserver reliabilities were analyzed by intraclass correlation coefficients (ICCs).

RESULTS

The distal fascicle of the AITFL was found in all specimens (100%). The mean distance from the most distal insertion of the AITFL's distal fascicle to the footprint centers of the ATFL, CFL, and the intersection center of the 2 ligaments on the fibula was 6.0 to 7.1 mm, 11.5 to 13.2 mm, and 9.0 to 10.0 mm, respectively. Excellent interobserver and intraobserver agreement (all ICCs > 0.9, P < .01) was shown in the anatomic measurements of these distances.

CONCLUSION

In this cadaveric study, we found that the distal fascicle was a constant structure of the AITFL in the lateral ankle. The distances from the most distal insertion of the AITFL's distal fascicle to the ligamentous footprint centers were reliable and may be used to identify the origins of the ATFL and CFL for lateral ankle ligament reconstruction.

CLINICAL RELEVANCE

This anatomic study validates the AITFL's distal fascicle as a potential landmark and, more importantly, determines the range of distances from AITFL's distal fascicle to the attachment centers of lateral ankle ligaments by anatomic measurements. The data may be used to identify the ATFL and CFL for lateral ankle stabilization surgery and become particularly valuable for endoscopic or arthroscopic techniques.

Avulsion fracture is associated with more pain after anatomic repair procedure for ATFL injury at the talar side

PURPOSE

To evaluate the clinical outcomes of anatomic repair procedure for chronic anterior talofibular ligament (ATFL) injury at the talar side, and to compare the outcomes between patients with and without concomitant avulsion fractures. It was hypothesized that anatomic repair procedure could produce similarly satisfactory outcomes for those two groups.

METHODS

Thirty-nine consecutive patients with chronic ATFL injuries at the talar side who underwent anatomic repair procedure at the department of sports medicine at Peking University Third Hospital between 2013 and 2018, were retrospectively evaluated. The pain visual analogue scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) score, Tegner score, and Foot & Ankle Outcome Score (FAOS) were recorded as the primary outcomes. Time to return to sports (RTS), surgical satisfaction, deficiency of ankle range of motion (ROM), recurrent sprain, and postoperative complications were recorded as the secondary outcomes. Outcomes were compared between patients with (Group A, 16 cases) and without (Group B, 23 cases) concomitant avulsion fractures.

RESULTS

The mean follow-up time was 79.4 ± 17.0 and 76.6 ± 18.5 months for Group A and B, respectively. VAS, AOFAS, Tegner, FAOS, and all subscale scores of FAOS were significantly improved in both groups at the final follow up. Patients in group A had inferior postoperative VAS, AOFAS, FAOS, and pain score of FAOS compared to group B (1.1 ± 1.1 vs. 0.4 ± 0.5, 89.1 ± 10.1 vs. 95.2 ± 5.2, 87.2 ± 7.2 vs. 91.5 ± 4.1, and 88.4 ± 11.3 vs. 96.7 ± 3.5, respectively).The mean time to RTS, rate of satisfaction and recurrent sprain had no significant differences between group A and B (6.1 ± 2.8, 93.8%, and 18.8% vs. 5.2 ± 2.2, 100.0%, and 13.0%, respectively), and the rate of ROM deficiency was significantly higher in group A (37.5 vs. 8.7%). Avulsion fracture was identified as an independent risk factor for inferior pain score of FAOS.

CONCLUSION

Anatomic repair procedure for chronic ATFL injuries at the talar side produces favourable results for patients with and without avulsion fractures at 5 to 10 years follow-up, however, avulsion fracture is associated with more pain.

LEVEL OF EVIDENCE

III.

Modified classifications and surgical decision-making process for chronic anterior talofibular ligament injuries based on the correlation of imaging studies and arthroscopic findings

PURPOSE

Surgical treatment of chronic ankle instability (CAI) typically includes ligament repair or reconstruction. Using preoperative ultrasonography or magnetic resonance imaging (MRI) to choose an appropriate arthroscopic procedure is still difficult. The aim of this study was to evaluate the correlation of imaging studies with arthroscopic findings and support the arthroscopic surgical decision-making process.

METHODS

One hundred twelve patients with chronic anterior talofibular ligament (ATFL) injuries were treated using the arthroscopic surgical decision-making process from November 2018 to August 2020. Preoperative imaging assessments using dynamic ultrasonography, MRI, and combined methods were applied to categorize the ATFL remnants into three quality grades ("good," "fair," and "poor"). Arthroscopic findings were classified into 6 major types (7 subtypes) and used to select an appropriate surgical procedure. Correlations between imaging studies, arthroscopic findings, and surgical methods were evaluated. Diagnostic parameters, clinical outcomes, and complications were also assessed.

RESULTS

There was a significant interobserver agreement in the evaluation of dynamic ultrasonography (0.954, P < 0.001), MRI (0.958, P < 0.001), and arthroscopy diagnosis (0.978, P < 0.001). There was a significant correlation between the modified imaging classifications, arthroscopic diagnostic types, and surgical procedures. The mean follow-up period was 33.58 ± 8.85 months. Significant improvements were documented in postoperative ankle functions when assessed with Karlson-Peterson scores and Cumberland Ankle Instability Tool scores. The risk of complications is also very low.

CONCLUSION

The modified classifications and surgical decision-making process based on dynamic ultrasonography, MRI, and arthroscopic findings, as proposed in this study, might help in selecting an appropriate arthroscopic surgical procedure for chronic ATFL injuries.

Deep Learning Approach for MRI in the Classification of Anterior Talofibular Ligament Injuries

BACKGROUND

Diagnosing anterior talofibular ligament (ATFL) injuries differs among radiologists. Further assessment of ATFL tears is valuable for clinical decision-making.

PURPOSE

To establish a deep learning method for classifying ATFL injuries based on magnetic resonance imaging (MRI).

STUDY TYPE

Retrospective.

POPULATION

One thousand seventy-three patients from a single center with ankle MRI within 1 month of reference standard arthroscopy (in-group dataset), were divided into training, validation, and test sets in a ratio of 8:1:1. Additionally, 167 patients from another center were used as an independent out-group dataset.

FIELD STRENGTH/SEQUENCE

Fat-saturation proton density-weighted fast spin-echo sequence at 1.5/3.0 T.

ASSESSMENT

Patients were divided into normal, strain and degeneration, partial tear and complete tear groups (groups 0-3). The complete tear group was divided into five sub-groups by location and the potential avulsion fracture (groups 3.1-3.5). All images were input into AlexNet, VGG11, Small-Sample-Attention Net (SSA-Net), and SSA-Net + Weight Loss for classification. The results were compared with four radiologists with 5-30 years of experience.

STATISTICAL TESTS

Model performance was evaluated by the receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC), and so on. McNemar's test was used to compare performance among the different models, and between the radiologists and models. The intraclass correlation coefficient (ICC) was used to assess the reliability of the radiologists. P < 0.05 was considered statistically significant.

RESULTS

The average AUC of AlexNet, VGG11, SAA-Net, and SSA-Net + Weight Loss was 0.95, 0.99, 0.99, 0.99 in groups 0-3 and 0.96, 0.99, 0.99, 0.99 in groups 3.1-3.5. The effect of SSA-Net + Weight Loss was similar to SSA-Net but better than AlexNet and VGG11. In the out-group test set, the AUC of SSA-Net + Weight Loss ranged from 0.89 to 0.99. The ICC of radiologists was 0.97-1.00. The effect of SSA-Net + Weight Loss was better than each radiologist in the in-group and out-group test sets.

DATA CONCLUSION

Deep learning has potential to be used for classifying ATFL injuries. SSA-Net + Weight Loss has a better diagnostic effect than radiologists with different experience levels.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 2.

Is There a Difference in the Distribution of Mechanoreceptors among the Three Sections of the Anterior Talofibular Ligament?

BACKGROUND

We investigated whether the distribution of mechanoreceptors in three sections of the anterior talofibular ligament (ATFL) differed.

METHODS

The ATFL was obtained from 29 ankles of 21 fresh-frozen cadavers and divided into fibular attachment, mid-ligament, and talar attachment parts. Histologically, mechanoreceptors were classified as Ruffini (type I), Vater-Pacini (type II), Golgi-Mazzoni (type III), and free nerve ending corpuscles (type IV); the presence of these mechanoreceptors was compared among the three ATFL sections.

RESULTS

Type I mechanoreceptors were significantly more numerous than the other receptor types. Comparing the three sections of the ATFL, the number of type I mechanoreceptors differed significantly between the mid-ligament and fibular attachment (p = 0.006), while the number of type III mechanoreceptors differed significantly between the talar and fibular attachments (p = 0.005) and between the mid-ligament and talar attachment (p = 0.011).

CONCLUSIONS

The four types of mechanoreceptors were distributed differently among the three sections of the ATFL. Type I mechanoreceptors were more numerous in all sections compared to the other receptors.

Ultrasound or MRI in the Evaluation of Anterior Talofibular Ligament (ATFL) Injuries: Systematic Review and Meta-Analysis

OBJECTIVES

Ankle sprains represent the second most common cause of emergency department access for musculoskeletal injury and lateral ankle ligament complex tears account for 850,000 cases annually in the United States with a relapse rate of 70%. Clinical examination is limited due to its subjectivity and the difficulty of identifying a specific involvement of the ligament; therefore, US and MRI are frequently requested. Therefore, the goal of this study is to analyze the available literature on the use of ultrasound (US) and magnetic resonance imaging (MRI) to diagnose injuries to the anterior talofibular ligament (ATFL) with a meta-analytic approach.

METHODS

According to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines, all studies regarding the diagnostic accuracy of ultrasound and magnetic resonance imaging ATFL injuries were searched and assessed. The data were obtained from two independent reviewers with 12 and 3 years of experience in meta-analysis. A QUADAS-2 (Quality Assessment of Studies of Diagnostic Accuracy Studies) checklist was carried out to assess the risk of biases. From the selected studies, the sensitivity, specificity, and accuracy data were extracted.

RESULTS

Nine studies were included. The results of the meta-analysis demonstrate a greater sensitivity for ultrasound [96.88 (95% CI: 94-99) (fixed effects); 97 (95% CI: 94-99) (random effects)] compared to MRI [88.50 (95% CI: 85-91) (fixed effects); 86.98 (95% CI: 77-94) (random effects)], p < 0.05. The result of this meta-analysis shows that the less expensive diagnostic technique is also the most sensitive for the diagnosis of ATFL tears. Ultrasound articles resulted to have non-heterogeneity [(p = 0.2816; I° = 21.4607%)].

CONCLUSION

This meta-analysis demonstrates that US appears to be a highly sensitive diagnostic technique for diagnosing tears of the ATFL. Compared to MRI, the sensitivity of US result was higher.

Progress in diagnosis and treatment of acute injury to the anterior talofibular ligament

Injury to the anterior talofibular ligament (ATFL) is a common acute injury of the lateral foot ligament. Untimely and improper treatment significantly affects the quality of life and rehabilitation progress of patients. The purpose of this paper is to review the anatomy and the current methods of diagnosis and treatment of acute injury to the ATFL. The clinical manifestations of acute injury to the ATFL include pain, swelling, and dysfunction. At present, non-surgical treatment is the first choice for acute injury of the ATFL. The standard treatment strategy involves the “peace and love” principle. After initial treatment in the acute phase, personalized rehabilitation training programs can be followed. These may involve proprioception training, muscle training, and functional exercise to restore limb coordination and muscle strength. Static stretching and other techniques to loosen joints, acupuncture, moxibustion massage, and other traditional medical treatments can relieve pain, restore range of motion, and prevent joint stiffness. If the non-surgical treatment is not ideal or fails, surgical treatment is feasible. Currently, arthroscopic anatomical repair or anatomical reconstruction surgery is commonly used in clinical practice. Although open Broström surgery provides good results, the modified arthroscopic Broström surgery has many advantages, such as less trauma, rapid pain relief, rapid postoperative recovery, and fewer complications, and is more popular with patients. In general, when treating acute injury to the ATFL, treatment management and methods should be timely and reasonably arranged according to the specific injury scenario and attention should be paid to the timely combination of multiple therapies to achieve the best treatment results.

Computer-Aided Ankle Ligament Injury Diagnosis from Magnetic Resonance Images Using Machine Learning Techniques

Ankle injuries caused by the Anterior Talofibular Ligament (ATFL) are the most common type of injury. Thus, finding new ways to analyze these injuries through novel technologies is critical for assisting medical diagnosis and, as a result, reducing the subjectivity of this process. As a result, the purpose of this study is to compare the ability of specialists to diagnose lateral tibial tuberosity advancement (LTTA) injury using computer vision analysis on magnetic resonance imaging (MRI). The experiments were carried out on a database obtained from the Vue PACS-Carestream software, which contained 132 images of ATFL and normal (healthy) ankles. Because there were only a few images, image augmentation techniques was used to increase the number of images in the database. Following that, various feature extraction algorithms (GLCM, LBP, and HU invariant moments) and classifiers such as Multi-Layer Perceptron (MLP), Support Vector Machine (SVM), k-Nearest Neighbors (kNN), and Random Forest (RF) were used. Based on the results from this analysis, for cases that lack clear morphologies, the method delivers a hit rate of 85.03% with an increase of 22% over the human expert-based analysis.

Imaging diagnosis for anterior talofibular ligament injury: a systemic review with meta-analysis

A definite diagnosis of ankle ligament injury is crucial, and many imaging examinations can be used. This review systematically analyzed the effectiveness of various examination methods in the diagnosis of anterior talofibular ligament (ATFL) injuries. Three English databases (PubMed, Embase, and Cochrane Library) and three Chinese databases (CNKI, VIP Database, and Wanfang Database) were searched and relevant studies were summarized. A total of 25 randomized controlled trials met the selection criteria, including six, 16, and three studies recruiting patients with acute, chronic, and both acute and chronic ATFL injuries, respectively. A total of 1409 participants were included. The pooled sensitivity rates of acute ATFL injuries were 82.1% (77.1%-86.5%) by magnetic resonance imaging (MRI) and 88.6% (82.0%-93.5%) by ultrasonography (US). The pooled sensitivity rates of chronic ATFL injuries were 86.3% (82.5%-89.5%) by MRI, 98.7% (95.3%-99.8%) by US, 74.4% (63.6%-83.4%) by stress radiography, and 100% (87.7%-100.0%) for MR arthrography. The pooled specificity rates of acute ATFL injuries were 37.8% (29.1%-47.2%) by MRI and 90.3% (80.1%-96.4%) by US. The pooled specificity rates of chronic ATFL injuries were 86.8% (81.3%-91.2%) by MRI, 94.0% (85.4%-98.3%) for US, 89.4% (76.9%- 96.5%) by stress radiography and 100% (54.1%-100.0%) by MR arthrography. In conclusion, US may be a valuable imaging technique with high sensitivity for diagnosing chronic lateral ankle ligament injuries.

Determining the Feasibility of Arthroscopic Anterior Talofibular Ligament Repair Utilizing a Novel Classification System

The purposes of this study were to classify anterior talofibular ligament injuries (ATFL), to find out the feasibility of arthroscopic ATFL repair according to injury type and to investigate the diagnostic validity of magnetic resonance imaging (MRI) of ATFL injuries by comparing MRI and arthroscopic findings. The 197 ankles (93 right, 104 left, and 12 bilateral) of 185 patients (90 men and 107 women; mean age, 33.5 years, range: 15-68 years) were treated by arthroscopic modified Broström procedure after a diagnosis of chronic lateral ankle instability. ATFL injuries were classified according to their grade and location (type P: partial rupture, type C1: fibular detachment, type C2: talar detachment, type C3: midsubstance rupture, type C4: absence of ATFL, type C5: os subfibulare). Among the 197 injured ankles, according to ankle arthroscopy, 67 were type P (34%), 28 were type C1 (14%), 13 were type C2 (7%), 29 were type C3 (15%), 26 were type C4 (13%), and 34 were type C5 (17%). The kappa value for the agreement between the arthroscopic findings and MRI findings was also high (0.85; 95% confidence interval, 0.79-0.91). Our results also supported the use of MRI for diagnosing ATFL injuries and showed that it is an informative tool during the preoperative period.

Anterior talofibular ligament remnant quality is important for achieving a stable ankle after arthroscopic lateral ankle ligament repair

PURPOSE

The relationship between ligament remnant quality and postoperative outcomes after arthroscopic lateral ankle ligament repair for chronic lateral ankle instability is controversial. This study aimed to determine whether the signal intensity of the anterior talofibular ligament on preoperative magnetic resonance imaging and ligament remnant quality identified on arthroscopy are associated with recurrent ankle instability after arthroscopic lateral ankle ligament repair.

METHODS

A total of 68 ankles from 67 patients with chronic lateral ankle instability who underwent arthroscopic lateral ankle ligament repair were retrospectively studied. The signal intensity of the anterior talofibular ligament was evaluated using T2-weighted magnetic resonance imaging. Arthroscopy was used to evaluate the thickness and mechanical resistance of the anterior talofibular ligament by hook palpation and to classify ankles into two groups: the present anterior talofibular ligament group with adequate mechanical resistance and the absent anterior talofibular ligament group with no mechanical resistance. The outcomes included recurrent ankle instability (respraining of the operated ankle after surgery) and Self-Administered Foot Evaluation Questionnaire scores.

RESULTS

Thirteen ankles were diagnosed with recurrent ankle instability. Patients with a high anterior talofibular ligament T2 signal intensity experienced more recurrent ankle instability than those with a low intensity. As determined via arthroscopy, the absent anterior talofibular ligament group had a higher rate of recurrent ankle instability than the present anterior talofibular ligament group. There were no significant differences in Self-Administered Foot Evaluation Questionnaire scores between patients with high and low anterior talofibular ligament T2 signal intensity, as well as between absent and present anterior talofibular ligament groups based on arthroscopy.

CONCLUSION

Poor quality of the anterior talofibular ligament remnant could result in recurrent ankle instability after arthroscopic lateral ankle ligament repair. Therefore, when treating chronic lateral ankle instability, surgeons should consider ligament quality.

LEVEL OF EVIDENCE

IV.

The Ratio of Stress to Nonstress Anterior Talofibular Ligament Length on Ultrasonography: Normative Values

Background:

Stress ultrasonography (US) has been shown to be a valid procedure for evaluating chronic anterior talofibular ligament (ATFL) injury. The ratio of stress/nonstress ATFL length (ATFL ratio) as measured on US is clinically useful; however, there are no published normative data concerning this ratio.

Purpose:

To report a normative value of the ATFL ratio on US and evaluate the relationships between sex, generalized joint laxity (GJL), and the grade of anterior drawer test (ADT).

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

The ATFL lengths were prospectively measured in the stress and nonstress positions (manual maximal anterior drawer position) for participants with noninjured ankles from March 2020 to March 2021. GJL was defined as a Beighton score ≥4. A manual ADT was also performed. The ATFL ratio was calculated, and the relationships between sex, GJL, and ADT grade were evaluated.

Results:

A total of 333 ankles in 184 participants (mean age, 24.5 ± 2.7 years; range, 20-33 years) were eligible for the analysis. GJL was found in 69 ankles (20.7%). The mean ATFL ratio was 1.08 ± 0.04 (95% CI, 1.08-1.09; range, 1.01-1.24), and there was a significant difference between male (1.07 ± 0.04; 95% CI, 1.07-1.08; range, 1.02-1.23) and female (1.09 ± 0.04; 95% CI, 1.08-1.10; range, 1.01-1.24) ankles (P = .001). In male ankles, the ATFL ratio was significantly greater in participants with GJL (1.11 ± 0.06 vs 1.07 ± 0.03; P = .02) or a higher grade of ADT (grade 2 vs grade 1: 1.11 ± 0.06 vs 1.07 ± 0.03, P = .002). These findings were not observed in female ankles.

Conclusion:

The normative value of the ATFL ratio on stress US was 1.07 ± 0.04 in men and 1.09 ± 0.04 in women. The ATFL ratio was affected by the presence of GJL in men but not in women. These findings will be useful for future studies seeking to establish the cutoff value of the ATFL ratio for diagnosing chronic lateral ankle stability on stress US.

Magnetic Resonance Accuracy in the Diagnosis of Anterior Talo-Fibular Ligament Acute Injury: A Systematic Review and Meta-Analysis

BACKGROUND

The studies about injury to the anterior talo-fibular ligament (ATFL) are focused mainly on chronic symptoms and chronic instability, and the literature about the accuracy of magnetic resonance imaging (MRI) in acute injuries is quite lacking.

METHODS

This systematic review with meta-analysis analyzes the diagnostic accuracy of MRI on acute ATFL injury. Relative studies were retrieved after searching three databases (MEDLINE, SCOPUS, and Cochrane Central Register of Controlled Trails). Eligible studies were summarized. The quality of the included articles was assessed using the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Data were extracted to calculate pooled sensitivity and specificity of MRI.

RESULTS

Seven studies met our inclusion and exclusion criteria. For MRI, the pooled sensitivities and specificity in diagnosing acute ATFL injury were respectively 1.0 (95% CI: 0.58-1) and 0.9 (95% CI: 0.79-0.96). Pooled LR+ and LR- were respectively 10.4 (95% CI: 4.6-23) and 0 (95% CI: 0-0.82).

CONCLUSION

This systematic review with meta-analysis investigated the accuracy of imaging for the diagnosis of acute ATFL injury. Our results demonstrated that MRI shows high diagnostic accuracy in the diagnosis of acute ATFL lesions. These results suggest that routine MRI in the case of suspected ATFL acute injury may be clinically useful, although this is not done in clinical practice due probably to high cost.

Development of a medical device compatible with MRI/CT to measure ankle joint laxity: the Porto Ankle Testing Device

Ankle sprains are common and often develop into chronic ankle instability. Ankle laxity is usually assessed by manual testing followed by magnetic resonance imaging to confirm the diagnosis. Manual testing however provides a subjective measure and is limited to the assessor sensibility. Current available technologies incorporate arthrometers to objectively measuring ankle laxity, but are not capable to assess the structural integrity of the capsuloligamentous structures. To overcome these limitations, we developed a novel medical device to assist in the diagnosis of ankle ligament injuries—the Porto Ankle Testing Device. With this device, it is possible to combine and correlate the assessment of the capsuloligamentous’ structural integrity with the joint functional competence (ie, joint multiplanar laxity). The main purpose of this work is to present the fundamental aspects and step-by-step development of the Porto Ankle Testing Device. We discuss the design specifications and technical requirements with the purpose to design and develop this medical device, described the features of the different components and explained the mechanical systems that are incorporated emulate manual testing and to measure the multiplanar ankle laxity. The preliminary findings are presented with the purpose to display the assessment protocol, the method of laxity measurement and the obtained results. We propose a unique and reliable medical device to safety and effectively assess ankle ligament injuries and contribute to enhance diagnosis, refine treatment indications and allow objective measurement of ligament laxity before and/or after stabilization surgery.

Evaluation of 3-Dimensional Magnetic Resonance Imaging (3D MRI) in Diagnosing Anterior Talofibular Ligament Injury

BACKGROUND It is challenging to entirely show the anterior talofibular ligament (ATFL) and accurately diagnose ATFL injury with traditional 2-dimensional (2D) magnetic resonance imaging (MRI). With the introduction of 3.0T MRI, a 3-dimensional (3D) MRI sequence can achieve images with high spatial resolution. This study aimed to evaluate the accuracy of 3D MRI and compare it with 2D MRI in diagnosing ATFL injury. MATERIAL AND METHODS This was a prospective study in which 45 patients with clinically suspected ATFL injury underwent 2D MRI, 3D MRI, and 3D model reconstruction followed by arthroscopic surgery between February 2018 and April 2019. Two radiologists who had over 11 and 13 years of musculoskeletal experience assessed the injury of ATFL in consensus without any clinical clues. Arthroscopic surgery results were the standard reference of MRI accuracy. RESULTS The 3D MRI results of ATFL injury showed the sensitivity of diagnosis of complete tears of 83% and specificity of 82%. The partial tears diagnosis sensitivity was 78%, and specificity was 100%. The sensitivity of diagnosis of sprains was 100%, and the specificity was 97%. The 3D MRI accuracy of diagnosis was 98% for no injury, 98% for sprain, 91% for partial tear, and 82% for complete tear. The difference in the diagnosis of sprain and partial tears by 3D MRI and 2D MRI was statistically significant (P<0.05). A 3D reconstruction model was successfully created for all patients. CONCLUSIONS 3D MRI may be a reliable and accurate method to detect ATFL injury. The 3D reconstruction model using 3D MRI sequences has excellent prospects in application.

Diagnosis and Treatment of Chronic Lateral Ankle Instability: Review of Our Biomechanical Evidence

Definitive diagnosis and optimal surgical treatment of chronic lateral ankle instability remains controversial. This review distills available biomechanical evidence as it pertains to the clinical assessment, imaging work up, and surgical treatment of lateral ankle instability. Current data suggest that accurate assessment of ligament integrity during physical examination requires the ankle to ideally be held in 16° of plantar flexion when performing the anterior drawer test and 18° of dorsiflexion when performing the talar tilt test, respectively. Stress radiographs are limited by their low sensitivity, and MRI is limited by its static nature. Surgically, both arthroscopic and open repair techniques appear biomechanically equivalent in their ability to restore ankle stability, although sufficient evidence is still lacking for any particular procedure to be considered a superior construct. When performing reconstruction, grafts should be tensioned at 10 N and use of nonabsorbable augmentations lacking viscoelastic creep must factor in the potential for overtensioning. Anatomic lateral ligament surgery provides sufficient biomechanical strength to safely enable immediate postoperative weight bearing if lateral ankle stress is neutralized with a boot. Further research and comparative clinical trials will be necessary to define which of these ever-increasing procedural options actually optimizes patient outcome for chronic lateral ankle instability.

Limited intrarater and interrater reliability of acute ligamentous ankle injuries on 3 T MRI

OBJECTIVES

To determine the diagnostic reliability of the Schneck grading system for acute ligamentous injuries of (1) the three major ligamentous ankle complexes, (2) the individual ankle ligaments and (3) the Sikka classification for syndesmosis injury.

METHODS

All acute ankle injuries in adult athletes (≥18 years), presenting to the outpatient department of a specialised Orthopaedic and Sports Medicine Hospital, within 7 days postinjury were screened for inclusion. Ankle injuries were excluded if imaging demonstrated a frank ankle fracture or if the 3 T MRI study could not be acquired within 10 days postinjury. Two radiologists graded the three major ligamentous complexes (lateral ankle complex, deltoid complex and syndesmosis complex) and their comprising individual ligaments according the four-grade Schneck grading system. Syndesmotic injuries were classified according the four-grade Sikka classification for consequent injury of the individual syndesmosis ligaments and the deltoid complex. Agreement and kappa (K) statistics were calculated to determine intrarater and interrater reliability.

RESULTS

Between September 2016 and September 2018, a total of 92 MR scans were obtained (87 patients). Interrater and intrarater reliability of the Schneck grading system was moderate to substantial for the lateral ankle complex (K=0.47-0.76), fair to almost perfect for the syndesmosis complex (K=0.37-0.89) and fair to moderate for the deltoid complex (K=0.14-0.51). For the individual ligaments, kappa values ranged from moderate to substantial for the anterior talofibular ligament (ATFL) (K=0.55-0.73), fair to substantial for the calcaneofibular ligament (K=0.31-0.62) and fair to almost perfect for the anteroinferior tibiofibular ligament (AITFL) (K=0.36-0.89). Diagnostic reliability of the Sikka classification ranged from moderate to almost perfect (K=0.51-0.95).

CONCLUSIONS

Grading of the three major ligamentous complexes and of the individual ankle ligaments according the Schneck grading system resulted in limited diagnostic reliability. When dichotomised for the presence of complete discontinuity, the interrater reliability of the Schneck grading system improved to substantial and almost perfect for the ATFL and AITFL, respectively. Classification of syndesmosis injury according the Sikka classification resulted in moderate interrater reliability.

Morphology of Anterior Talofibular Ligament After Arthroscopic Lateral Ankle Ligament Repair

BACKGROUND

Arthroscopic lateral ankle ligament repair for chronic lateral ankle instability (CLAI) yields good clinical results. However, the healing process of the ligament after anatomical repair remains unclear. This study evaluated the functional and patient-based outcomes for CLAI patients who underwent arthroscopic lateral ankle ligament repair and the morphological condition of the repaired anterior talofibular ligament (ATFL).

METHODS

We retrospectively reviewed 47 patients (50 ankles) who underwent arthroscopic lateral ankle ligament repair for CLAI (mean follow-up, 14 months). The Japanese Society for Surgery of the Foot Ankle-Hindfoot (JSSF) scale score and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) were assessed preoperatively and 12 months postoperatively. Magnetic resonance imaging (MRI) was performed preoperatively and at 6 and 12 months postoperatively to evaluate the ATFL. The functional and patient-based outcomes were compared between the group with repaired ATFLs and high signal intensity and the group with repaired ATFLs and low signal intensity.

RESULTS

The mean JSSF score improved significantly from 72.3 ± 11.6 preoperation to 95.3 ± 5.4 at 12 months postoperation. The MRI findings at 12 months postoperation showed that each repaired ATFL had a linear band structure from the talar to the fibular attachment site, and 41 of 50 ankles (82%) had low signal intensity of the ligament. On the SAFE-Q, the social functioning scores at 12 months postoperation were significantly higher in the low signal intensity group than in the high signal intensity group.

CONCLUSION

Arthroscopic lateral ankle ligament repair for CLAI yielded good functional and patient-based outcomes and restored the morphological condition of the ATFL.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Evaluation of the anterior inferior tibiofibular and anterior talofibular ligaments using 2D oblique coronal imaging and 3D isotropic resolution T2-weighted fast spin-echo sequences at 3.0 T: Is there additional diagnostic value?

INTRODUCTION

To compare diagnostic performance of additional two-dimensional (2D) oblique coronal view and three-dimensional (3D) T2-weighted fast spin-echo(FSE) images for diagnosing injury of the anterior inferior tibiofibular (AiTFL) and anterior talofibular ligaments (ATFL).

METHODS

This study included 48 patients with ankle sprain who had undergone MRI using standard protocol and two additional sequences with 2D oblique coronal and 3D isotropic images, followed by arthroscopic surgery. Ligament injuries was subdivided by intact tendon, partial or complete tear. Retrospectively, two musculoskeletal radiologists respectively reviewed three image sets of MR including 2D axial image only (set 1), 2D axial and oblique coronal images (set 2), and 2D axial with 3D-isotropic images (set 3). Using arthroscopic findings as reference standard, diagnostic performances of both methods were analysed by the area under the curve (AUC).

RESULTS

Arthroscopy confirmed 13 AiTFL and 41 ATFL injuries. For AiTFL, when set 1 and set 3 were compared, AUC value was significantly higher for set 3 (P < 0.05). However, there was no significant difference between AUC values for set 2 and set 3 sequences by either reader for either type of tear (P > 0.05). For ATFL, both readers found there was no significant difference in AUC values between set 1 and set 3 and between set 2 and set 3.

CONCLUSION

Additional oblique coronal sequence demonstrated better diagnostic performance for AiTFL injury than conventional and isotropic imaging did. This sequence showed as much diagnostic accuracy as isotropic sequence for evaluation of ATFL injury.

The role of the anterior talofibular ligament area as a morphological parameter of the chronic ankle sprain

BACKGROUND

Repetitive microtrauma can result in a hypertrophied ATFL. Previous studies have found that the anterior talofibular ligament thickness (ATFLT) is correlated with lateral ankle sprains, ligament injuries and chronic stroke in patients, and thickened anterior talofibular ligament (ATFL) has been considered to be a major morphologic parameter of hypertrophied ATFL. However, hypertrophy is different from thickness. Thus, we devised the anterior talofibular ligament area (ATFLA) as a new morphological parameter to evaluate the hypertrophy of the whole ATFL.

METHODS

ATFL samples were collected from 53 patients with sprain group and from 50 control subjects who underwent magnetic resonance imaging (MRI) of the ankle and revealed no evidence of lateral ankle injury. Axial T1-weighted MRI images were collected at the ankle level from all subjects. We measured the ATFLA and ATFLT at the anterior margin of the fibular malleolus to the talus bone on the MRI using a picture archiving and communications system. The ATFLA was measured as the whole cross-sectional ligament area of the ATFL that was most hypertrophied in the axial MR images. The ATFLT was measured as the thickest point between the lateral malleolus and the talus of the ankle.

RESULTS

The average ATFLA was 25.0 ± 6.0 mm² in the control group and 47.1 ± 10.4 mm² in the sprain group. The average ATFLT was 2.3 ± 0.6 mm in the control group and 3.8 ± 0.6 mm in the hypertrophied group. Patients in sprain group had significantly greater ATFLA (p < 0.001) and ATFLT (p < 0.001) than the control subjects. A Receiver Operator Characteristics curve analysis showed that the best cut-off point of the ATFLA was 34.8 mm², with 94.3% sensitivity, 94.0% specificity, and an AUC of 0.97 (95% CI, 0.94-1.00). The optimal cut-off point of the ATFLT was 3.1 mm, with 86.8% sensitivity, 86.0% specificity, and AUC of 0.95 (95% CI, 0.92-0.99).

CONCLUSION

ATFLA is a new morphological parameter for evaluating chronic ankle sprain, and may even be more sensitive than ATFLT.

Radiologic Evaluation of the Effect of Distal Tibiofibular Joint Anatomy on Arthroscopically Proven Ankle Instability

BACKGROUND

Ankle sprains occur frequently in both athletes and the general population. The social and economic consequences can be significant. In an effort to understand the injury, dynamic and static structures around the ankle have been investigated in detail, but anatomical factors predisposing to lateral ankle instability have not been fully clarified. The aim of this study was to radiologically investigate the relationship between bony variations of the distal tibiofibular joint and arthroscopically proven ankle instability.

METHODS

Fifty patients with arthroscopically proven ankle instability and 50 patients without instability were included in this study. Measurements were obtained from a magnetic resonance imaging (MRI) section 1 cm proximal to the tibiotalar joint; distal tibiofibular joint anterior facet length (a), posterior facet length (b), angle between the anterior and posterior facets (c), fibular notch depth (d), tibia thickness (e), and fibula thickness (f) was measured.

RESULTS

It was found that instability was more frequent when the length of a (P < .001) and e (P < .001) were shorter. In addition, when value of a/b and e/f were evaluated, it was observed that the number of individuals who had instability increased as the ratio became smaller (P < .016-.020, respectively). Pearson correlation analysis indicated strong negative correlation between the values of a-e and instability (r = -0.348, P < .001, and r = -0.328, P = .001; respectively).

CONCLUSION

Lateral ankle sprains are common, and a clear understanding of the relevant structures and clinical function of the ankle complex should extend beyond the talocrural joint. This study demonstrated that the presence of narrow anterior facet (a) and thinner tibia (e) were strongly correlated with lateral ankle instability.

LEVEL OF EVIDENCE

Level III, retrospective case control study.

Increased ATFL-PTFL angle could be an indirect MRI sign in diagnosis of chronic ATFL injury

PURPOSE

Magnetic resonance imaging (MRI) has relatively low accuracy in diagnosing chronic anterior talofibular ligament (ATFL) injury. This study's purpose was to evaluate the angle between the ATFL and posterior talofibular ligament (PTFL) as a new indirect MRI sign of chronic ATFL injury in patients with mechanical ankle instability (MAI).

METHODS

This study included 200 participants: 105 patients with MAI and 95 patients seen at our institution for reasons unrelated to ankle instability. MR images of all 200 participants were reviewed. The ATFL-PTFL angle in the axial plane was measured and compared between groups. Receiver operating characteristic curves (ROC) were used to analyze ATFL-PTFL angles in participants with and without ATFL injury. The sensitivity and specificity of this method for diagnosing ATFL injury were calculated.

RESULTS

The mean ATFL-PTFL angle was significantly larger among MAI patients than among control patients (81.5° ± 9.8° vs 75.2° ± 8.9°, respectively; P < 0.01). The area under the ROC was 0.789 (P < 0.01). The optimal cut-off point for diagnosing ATFL injury on the basis of the ATFL-PTFL angle was 79.0° (sensitivity 0.89, specificity 0.67).

CONCLUSION

The ATFL-PTFL angle was significantly larger among MAI patients than among those without MAI. Increased ATFL-PTFL angle offers a new indirect MRI sign for diagnosing chronic ATFL injury. The ATFL-PTFL angle can be used not only to improve the accuracy of diagnosis of chronic ATFL injury, but also to evaluate the restoration of normal ankle joint geometry after lateral ligament reconstruction.

LEVEL OF EVIDENCE

III.

Lower Signal Intensity of the Anterior Talofibular Ligament is Associated with a Higher Rate of Return to Sport After ATFL Repair for Chronic Lateral Ankle Instability

BACKGROUND

The treatment strategy for anterior talofibular ligament (ATFL) injury is usually determined by the ATFL remnant condition during surgery. Preoperative magnetic resonance imaging (MRI)-based signal intensity of the ATFL remnant, represented by the signal/noise ratio (SNR) value, can reveal the ATFL remnant condition. Thus far, there is a lack of evidence regarding the relationship between the ATFL remnant condition and functional outcomes.

PURPOSE/HYPOTHESIS

The purpose was to quantitatively evaluate whether the MRI-based ATFL ligament SNR value is related to functional outcomes after ATFL repair for ankles with chronic lateral ankle instability. The hypothesis was that a lower preoperative SNR is related to a better clinical outcome, particularly a higher rate of return to sport.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

First, a preliminary study was performed to measure the ATFL SNR in preoperative MRI, the results of which suggested that a preoperative SNR >10.4 was indicative of a poor ATFL condition. Then, a cohort study was retrospectively performed with consecutive patients who underwent open repair of ATFL injuries between January 2009 and August 2014. Accordingly, the patients were divided into 2 groups: high SNR (HSNR; ≥10.4) and low SNR (LSNR; <10.4). Functional outcomes based on the American Orthopaedic Foot and Ankle Society (AOFAS) score, Karlsson Ankle Functional Score (KAFS), and Tegner Activity Scale were then compared between the HSNR group and the LSNR group.

RESULTS

Ultimately, 70 patients were available for the final follow-up: 37 in the HSNR group and 33 in the LSNR group. No significant difference was detected between the HSNR group and the LSNR group in terms of the AOFAS score, KAFS, or Tegner Activity Scale (P > .05 for all) preoperatively. At the final follow-up, the mean ± SD AOFAS score in the LSNR group (92 ± 6) was higher than that in the HSNR group (87 ± 12), although no significant difference was detected postoperatively (P = .16). The mean KAFS in the LSNR group (94 ± 7) was significantly higher than that in the HSNR group (88 ± 11) postoperatively (P = .03). At follow-up, the mean Tegner score in the LSNR group (6; range, 3-7) was significantly higher than that in the HSNR group (5; range, 1-8) postoperatively (P = .03). Patients in the LSNR group had a significantly higher percentage of sports participation than those in the HSNR group (91% vs 65%, P = .02) postoperatively.

CONCLUSION

A lower signal intensity in the ATFL ligament based on preoperative MRI is associated with a better clinical outcome, particularly a higher rate of return to sport.

Evaluating and Differentiating Ankle Instability

Given the prevalence of lateral ankle sprains during physical activity and the high rate of reinjury and chronic ankle instability, clinicians should be cognizant of the need to expand the evaluation of ankle instability beyond the acute time point. Physical assessments of the injured ankle should be similar, regardless of whether this is the initial lateral ankle sprain or the patient has experienced multiple sprains. To this point, a thorough injury history of the affected ankle provides important information during the clinical examination. The physical examination should assess the talocrural and subtalar joints, and clinicians should be aware of efficacious diagnostic tools that provide information about the status of injured structures. As patients progress into the subacute and return-to-activity phases after injury, comprehensive assessments of lateral ankle-complex instability will identify any disease and patient-oriented outcome deficits that resemble chronic ankle instability, which should be addressed with appropriate interventions to minimize the risk of developing long-term, recurrent ankle instability.

In vivo arthrometer measurements of mechanical ankle instability-A systematic review

Chronic ankle instability is caused by functional and/or mechanical deficits. To differentiate the two entities, mechanical ankle instability can be assessed using arthrometers. The measurement of mechanical instability is essential, since it can only be addressed surgically. The aim of this systematic literature review was to find out whether chronic mechanical ankle instability could be adequately and objectively assessed using in vivo arthrometer measurements. Articles were included if the main focus was to evaluate the contribution of mechanical deficits to chronic ankle instability and if they provided sufficient description of the device used. This systematic review was performed according to the PRISMA-recommendations. Initially 47 articles were screened for eligibility, of which 33 studies reporting 10 different devices were included. While the reliability of the measurements was mostly good to excellent, only two studies aimed to assess the sensitivity and specificity of their results in regard to chronic ankle instability. Several devices reported conflicting results about mechanical deficits. In summary, this systematic review reveals a substantial deficit in diagnostic accuracy when assessing mechanical ankle instability in a clinical setting. Biases in recruiting and classification of participants raise the question whether the two entities of functional and mechanical ankle instability are properly defined. Clinical Significance: In recent years, this may have led to a misinterpretation of mechanical deficits and the subsequent need for surgical intervention. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Occurrence of Lateral Ankle Ligament Disease With Stage 2 to 3 Adult-Acquired Flatfoot Deformity Confirmed via Magnetic Resonance Imaging: A Retrospective Study

Lateral hindfoot pain associated with stage 2 to 3 adult-acquired flatfoot is often attributed to subfibular impingement. Preoperative magnetic resonance imaging (MRI) is generally performed to assess the extent of degeneration within the posterior tibial tendon, attenuation of medial soft tissue constraints, and degeneration of hindfoot and/or ankle articulations. The purpose of this study is to determine the incidence of lateral collateral ligament disease/injury associated with stages 2 and 3 adult-acquired flatfoot. The subjects were identified using a searchable computerized hospital database between 2015 and 2017. Stage 2 or 3 adult-acquired flatfoot deformity was confirmed in patients via chart review and MRI analysis. Lateral ankle ligament injury was confirmed using patient MRI results per the hospital radiologist and documented within the patients' chart. Inclusion criteria required that patients be diagnosed with Johnson and Strom stage 2 or 3 flatfoot deformity with documented lateral ankle pain and that preoperative MRI scans be available with the radiologist's report. Patient exclusion criteria included patients <18 years of age, patients with flatfoot deformity caused by previous trauma, tarsal coalition, neuropathic arthritis, patients with previous surgery, or patients with incomplete medical records. In total, 118 patients were identified with these parameters. Of the 118 patients, 74 patients (62.7%) had documented lateral ankle ligament injury on MRI. Of the 77 patients with stage 2 adult-acquired flatfoot, 55 (71.4%) had confirmed lateral ankle ligament injury on MRI. Of the 41 patients with stage 3 adult-acquired flatfoot, 19 (46.3%) had confirmed lateral ankle ligament injury on MRI. This study demonstrates a relatively high incidence of lateral ligament disease associated with adult-acquired flatfoot deformity. These findings might have long-term implications regarding ankle arthritis after surgical management of adult-acquired flatfoot.

Reliability and validity of different ankle MRI scanning planes for the anterior talofibular ligament injury diagnosis: a cadaveric study

Background

The objective of the current study is to compare reliability, accuracy, sensitivity, and specificity in magnetic resonance imaging (MRI) evaluation of anterior talofibular ligament (ATFL) among the routine axial scanning plane, oblique axial-coronal scanning plane, and oblique axial-sagittal scanning plane.

Methods

Twenty cadaveric feet were studied. ATFL was exposed before scanning. Routine axial, oblique axial-coronal, and oblique axial-sagittal MRI scanning of 20 ATFL-intact cadaveric feet were acquired utilizing a 1.5-T MRI unit. The scans were repeated on the 20 cadaveric feet after the ATFL was artificially injured. In total, 120 sets of MR images were obtained and were randomly numbered. Three independent observers who were blinded to the experiment evaluated the images. Interobserver agreement, sensitivity, specificity, and accuracy were calculated and compared between different scanning planes utilizing the McNemar test.

Results

The interobserver agreement was fair to good (kappa, 0.55 to 0.65) in the routine axial plane, fair to good (kappa, 0.557 to 0.75) in the oblique axial-sagittal plane, and excellent (kappa, 0.85 to 0.95) in the oblique axial-coronal plane. The accuracy was significantly higher when utilizing oblique axial-coronal MRI scanning than routine axial MRI scanning (reader 1: p = .018; reader 2: p = .005).

Conclusions

The diagnostic accuracy of oblique axial-coronal plane MRI was higher than the routine axial plane concerning ATFL injury, and the interobserver agreement was excellent. The oblique axial-coronal plane could be added to the MRI scanning protocol during clinical practices to improve the diagnostic accuracy of ATFL injury.

Arthroscopic classification of chronic anterior talo-fibular ligament lesions in chronic ankle instability

BACKGROUND

The surgical treatment of chronic ankle instability (CAI) relies chiefly on anterior talo-fibular ligament (ATFL) repair (with or without augmentation) or anatomical reconstruction with a tendon graft. Arthroscopy enables not only a complete assessment and the same-stage treatment of concomitant articular lesions, but also an accurate assessment of ligament lesions. Pre-operative imaging studies (MRI, CT, US) may fail to provide sufficient detail about chronic ATFL lesions to guide the decision between repair and reconstruction. The aim of this study was to develop an arthroscopic classification of chronic ATFL lesions designed to assist in selecting the optimal surgical technique.

MATERIAL AND METHODS

Sixty-nine anterior ankle arthroscopy videos recorded before surgery for CAI were studied retrospectively. ATFL dissection was performed in all patients. Based on the video analysis, five ATFL grades were identified: 0, normal ATFL thickness and tension; 1, ATFL distension with normal thickness; 2, ATFL avulsion with normal thickness; 3, thin ATFL with no resistance during the hook test; and 4, no ATFL, with a bald malleolus. Intra- and interobserver reproducibility of the arthroscopic classification of chronic ATFL lesions was evaluated by computing the kappa coefficients (κ) after assessment by two independent observers.

RESULTS

All 69 ATFLs were classified as abnormal (none was grade 0). Each ATFL could be matched to a grade. Intra-observer agreement was good for both observers: κ was 0.67 with 75% of agreement for one observer and 0.68 with 76% of agreement for the other observer. Inter-observer agreement was fair to good, with κ values ranging from 0.59 to 0.88 and agreement from 70% to 91%.

DISCUSSION

Arthroscopic ATFL dissection is a simple procedure that provides a highly accurate assessment of ATFL lesions and mechanical resistance, focussing chiefly on the superior ATFL. Grade 1 and 2 lesions can be repaired using the Broström-Gould procedure, whereas grade 3 and 4 lesions require anatomic reconstruction with grafting.

CONCLUSION

This arthroscopic classification of chronic ATFL lesions confirms the diagnostic role for arthroscopy in assessing the ligaments in patients with CAI. It is helpful for determining the best surgical technique for stabilising the ankle. These results must be confirmed in a larger study.

Imaging diagnosis for chronic lateral ankle ligament injury: a systemic review with meta-analysis

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.

Simultaneous Radiographic Technique to Evaluate Ankle Instability

The use of ankle stress radiographs is common to evaluate ankle instability. However, the majority of the studies report the use of a manual method to apply the stress, increasing radiation exposure to the physician. Furthermore, as reported in other studies, the force applied during the stress may vary between examiners according the strength and experience. In this Technical Note, we describe our preferred method to evaluate ankle instability, either using an inversion or eversion stress, avoiding the necessity of a physician in the radiographic room.

Quantitative magnetic resonance imaging (MRI) analysis of anterior talofibular ligament in lateral chronic ankle instability ankles pre- and postoperatively

BACKGROUND

The aim of this study was to quantitatively evaluate and characterize the dimension and signal intensity of anterior talofibular ligament (ATFL) using 3.0 T MRI in the mechanical ankle instability group pre- and postoperatively.

METHODS

A total of 97 participants were recruited retrospectively in this study, including 56 with mechanical chronic ankle instability (CAI group) and 41 without ankle instability (Control group). All the subjects accepted MRI preoperatively. Among the 56 CAI patients, 25 patients, who accepted modified Broström repair of ATFL, underwent a MRI scan at follow-up. The ATFL dimension (length and width) and signal/noise ratio (SNR) were measured based on MRI images. The results of the MRI studies were then compared between groups.

RESULTS

The CAI group had a significantly higher ATFL length (p = 0.03) or ATFL width (p < 0.001) compared with the control group. The mean SNR value of the CAI group was significantly higher than that of the control group (p = 0.006). Furthermore, the mean SNR value of the ATFL after repair surgery (8.4 ± 2.4) was significantly lower than that of the ATFL before surgery (11.2 ± 3.4) (p < 0.001). However, no significant change of ATFL length or ATFL width were observed after repair surgery.

CONCLUSIONS

CAI ankles had a higher ATFL length or width as well as higher signal intensity compared with stable ankles. After repair surgery, the mean SNR value of the ATFL decreased, indicating the relaxed ATFL becomes tight postoperatively.

Talonavicular ligament: prevalence of injury in ankle sprains, histological analysis and hypothesis of its biomechanical function

OBJECTIVE

To assess the prevalence of injury of the talonavicular ligament (TNL) in ankle sprains, its anatomy and the stability of the talonavicular joint (TNJ) before and after dividing the TNL in a cadaver.

METHODS

During a prospective study of 100 patients to assess the outcome of ankle injuries, we noted high incidence of TNL injuries; we will discuss here the TNL findings. Each patient had undergone ultrasound and cone beam CT examination of the ankle. Six TNLs were dissected off fresh-frozen cadaveric feet for histological analysis. In further six cadaveric feet, the stability of the TNJ was assessed by mechanical stress before and after division of the TNL; movement at the joint was assessed by measuring the distance between the talus and navicular bone [talonavicular distance (TD)] using ultrasound. The TD was measured on ten randomly selected ultrasound images by three independent observers and repeated twice by a single observer to determine the inter- and intraobserver reliability.

RESULTS

21% of the patients had an injury to the TNL. Histological examination demonstrated a dense connective tissue composed of bundles of collagen in parallel arrangement along the ligament length. The interobserver and intraobserver reliability of the TD showed almost perfect agreement. Displacement at the TNJ after stress with the TNL intact measured 0.18 ± 0.08 cm and 0.29 ± 0.07 cm (p < 0.005) when divided.

CONCLUSION

The TNL is surprisingly commonly injured in ankle sprains. Its anatomy and histology suggest a role in tensile force transmission during the windlass mechanism in gait. Advances in knowledge: Injury to the TNL is common and has not been described. Its anatomy suggests resistance to tensile forces and its injury allows excessive movement at the TNJ.

Chronic ankle instability: Arthroscopic anatomical repair

INTRODUCTION

Ankle sprains are one of the most common injuries. Despite appropriate conservative treatment, approximately 20-40% of patients continue to have chronic ankle instability and pain. In 75-80% of cases there is an isolated rupture of the anterior talofibular ligament.

MATERIAL AND METHOD

A retrospective observational study was conducted on 21 patients surgically treated for chronic ankle instability by means of an arthroscopic anatomical repair, between May 2012 and January 2013. There were 15 men and 6 women, with a mean age of 30.43 years (range 18-48). The mean follow-up was 29 months (range 25-33). All patients were treated by arthroscopic anatomical repair of anterior talofibular ligament. Four (19%) patients were found to have varus hindfoot deformity. Associated injuries were present in 13 (62%) patients. There were 6 cases of osteochondral lesions, 3 cases of posterior ankle impingement syndrome, and 6 cases of peroneal pathology. All these injuries were surgically treated in the same surgical time.

RESULTS

A clinical-functional study was performed using the American Orthopaedic Foot and Ankle Society (AOFAS) score. The mean score before surgery was 66.12 (range 60-71), and after surgery it increased up to a mean of 96.95 (range 90-100). All patients were able to return to their previous sport activity within a mean of 21.5 weeks (range 17-28). Complications were found in 3 (14%) patients.

CONCLUSIONS

Arthroscopic anatomical ligament repair technique has excellent clinical-functional results with a low percentage of complications, and enables patients to return to their previous sport activity within a short period of time.

Accuracy of magnetic resonance imaging in diagnosing lateral ankle ligament injuries: A comparative study with surgical findings and timings of scans

Objective

This study aimed to evaluate the accuracy of magnetic resonance imaging (MRI) in diagnosing lateral ankle ligament injuries and the effect of differences in time duration from injury to MRI.

Methods

Data were collected prospectively from 82 patients who underwent MRI and lateral ligament reconstruction, and were divided into either acute (≤3 months) or chronic (>3 months) group based on injury interval. Findings were classified as normal, partial, or complete tears of the anterior talofibular ligament (ATFL) and the calcaneofibular ligament (CFL). MRI results were compared with intraoperative findings and their accuracies were assessed using descriptive statistics.

Results

The accuracy of MRI for partial and complete tears of the ATFL was 74% and 79%, respectively, with sensitivity and specificity of 64% and 86% for partial tears, and 78% and 80% for complete tears, respectively. The accuracy of MRI was 66% and 88% for partial and complete tears of the CFL with a sensitivity and specificity of 41% and 87% for partial tears, and 61% and 95% for complete tears, respectively. A decrease in the MRI accuracy was observed in the chronic group.

Conclusion

MRI is accurate in diagnosing ATFL injuries. It is specific but not sensitive for CFL tears. The accuracy is higher in the acute setting of 3 months or less from time of injury to MRI.