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

Maisonneuve fracture treated with short leg cast: A case report with 41-month follow-up

RATIONALE

Maisonneuve fracture is a specific type of severe ankle injury. To our current knowledge, once a Maisonneuve fracture is diagnosed, the surgery is always recommended for fear of sequelae from inaccurate joint reconstruction. However, in this case, we treated a Maisonneuve fracture with a short leg cast, and the 41-month follow-up showed a favorable outcome with no post-traumatic osteoarthritis, chronic pain, and instability. Therefore, this case provides evidence for the feasibility of conservative treatment of Maisonneuve fracture.

PATIENT CONCERNS

A female patient in her early twenties sprained her left ankle while running, suffering regional pain, swelling, and limited mobility.

DIAGNOSES

We diagnosed a Maisonneuve fracture with superior fibular fracture and Volkmann tuberosity fracture, a slight separation of inferior tibiofibular syndesmosis (ITS).

INTERVENTIONS

The patient rejected our surgical recommendations in favor of nonsurgical treatment, in addition to refusing immobilization of the knee. Consequently, we had to treat her with a short leg cast for 8 weeks and asked her to return for regular follow-up visits.

OUTCOMES

At the final follow-up, the radiography showed complete healing of proximal fibula fracture. The patient reported no discernible subjective differences between her bilateral ankles. The range of motion of the left ankle was measured at 22° of dorsiflexion and 40° of plantarflexion. Functional assessments using Olerud-Molander ankle scale and American Orthopedic Foot and Ankle Society Ankle-Hindfoot scale both scored 100 points. Additionally, the radiographic assessment classified arthritis as stage 0 according to Morrey-Wiedeman classification.

LESSONS

To avoid missing and misdiagnosing, the physical examination should always extend to 2 neighboring joints. Secondly, if a Maisonneuve fracture is suspected, further computed tomography scans, radiography, and magnetic resonance imaging can help to determine the stability of the ITS and the integrity of the lateral collateral ligaments before making therapeutic decisions. Finally, considering the lateral collateral ligaments may remain intact, we recommend stabilizing ITS by repairing the medial ligaments, which can be conducted arthroscopically and be more minimally invasive, providing an elastic fixation that aligns better with the biomechanics of the ITS which is characterized as a micro-mobile rather than fully fixed joint.

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.

Regional plantar forces and surface geometry variations of a chronic ankle instability population described by statistical shape modelling

BACKGROUND

Understanding detailed foot morphology as well as regional plantar forces could provide insight into foot function and provide recommendation for footwear design for chronic ankle instability (CAI) people.

RESEARCH QUESTION

This study presented 3-dimensional statistical shape models of feet from three different populations including CAI, copers and healthy individuals, with regional plantar forces also acquired.

METHODS

Sixty-six males (22 participants per group) were included in this study to capture 3-dimensional foot shapes under a standing condition and regional plantar forces during a cutting maneuver. Principal component analysis was performed to generate a mean foot shape of each group as well as modes of variations. A generalized procrustes analysis was used to achieve rapid registration of mean shapes. Besides, regional plantar forces and contact duration among these three populations were compared.

RESULTS

For 3-dimensional foot shapes, although no significant differences of the average distance between each mode and mean shape were found among three populations, there were subtle variations in mean shapes. The CAI population presented a more bulging of the lateral malleolus; copers were characterized by the flexion of the lesser toes, a more bulging of the medial foot in the sagittal plane; and healthy individuals showed a greater heel width and a more bulging of the heel in the sagittal plane. In terms of plantar forces, healthy individuals had significantly greater summated plantar forces and greater plantar forces in the lateral heel area during the early contact phase compared to copers and CAI participants.

SIGNIFICANCE

Overall, this study suggested that repetitive ankle sprains may lead to the bulging of the lateral malleolus. Further, CAI and copers seem to stabilize the ankle joint by medially shifting the center of pressure compared to healthy individuals under the static and less challenging dynamic conditions.

Clinical Relevance and Function of Anterior Talofibular Ligament Superior and Inferior Fascicles: A Robotic Study

BACKGROUND

Ankle lateral ligament sprains are common injuries in sports, and some may result in persistent ankle pain and a feeling of instability without clinical evidence of instability. The anterior talofibular ligament (ATFL) has 2 distinct fascicles, and recent publications have suggested that injury isolated to the superior fascicle might be the cause of these chronic symptoms. This study aimed to identify the biomechanical properties conferred by the fascicles in stabilizing the ankle in order to understand potential clinical problems that may follow when the fascicles are injured.

PURPOSE/HYPOTHESIS

The aim of this study was to determine the contribution of superior and inferior fascicles of the ATFL in restraining anteroposterior tibiotalar resistance, internal external tibial rotation resistance, and inversion eversion talar rotation resistance. It was hypothesized that an isolated injury of the ATFL superior fascicle would have a measurable effect on ankle stability and that the superior and inferior fascicles would restrain different motions of the ankle.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A robotic system with 6 degrees of freedom was used to test ankle instability in 10 cadavers. Serial sectioning following the most common injury pattern (from superior to inferior fascicles) was performed on the ATFL while the robot ensured reproducible movement through a physiological range of dorsiflexion and plantarflexion.

RESULTS

Sectioning of only the ATFL superior fascicle had a significant and measurable effect on ankle stability, resulting in increased internal rotation and anterior translation of the talus, especially in plantarflexion. Sectioning of the entire ATFL resulted in significantly decreased resistance in anterior translation, internal rotation, and inversion of the talus.

CONCLUSION

Rupture of only the superior fascicle of the ATFL may lead to minor instability or microinstability of the ankle joint, without objective clinical findings of gross clinical laxity.

CLINICAL RELEVANCE

Some patients develop chronic symptoms after an ankle sprain without overt signs of instability. This may be explained by an isolated injury to the ATFL superior fascicle, and diagnosis may require careful clinical evaluation and magnetic resonance imaging examination looking at the individual fascicles. It is possible that such patients may benefit from lateral ligament repair despite having no gross clinical instability.

Can virtual touch tissue imaging quantification be a reliable method to detect anterior talofibular ligament type I injury at the acute, subacute, and chronic stages?

Background

Anterior talofibular ligament (ATFL) injury affects ankle joint stability. To date, very few studies have examined tissue stiffness changes inside injured ligaments. Virtual touch tissue imaging quantification (VTIQ) allows for the non-invasive quantitative measurement of tissue stiffness. The present study aimed to examine the efficacy of VTIQ as a method for detecting ligament injury.

Methods

A total of 206 patients diagnosed with unilateral ATFL type I injury (81 acute cases, 69 subacute cases, and 56 chronic cases) were reviewed retrospectively. Shear wave velocity (SWV) values were collected from both the injured and non-affected sides of the ATFL using a virtual touch tissue imaging quantification technique (ACUSON Oxana 2, Siemens Medical Solutions USA, Inc.).

Results

The average SWV of injured ATFL was 4.09±1.15 m/s in the acute group, 5.60±1.39 m/s in the subacute group, and 7.74±1.44 m/s in the chronic group (P<0.001). The SWV values of the ATFL on the non-affected side were almost identical (acute 7.50±1.12 m/s, subacute 7.53±1.06 m/s, and chronic 7.61±1.30 m/s; P>0.05). The injured ATFL had a significantly lower SWV value than the non-affected ATFL in the acute and subacute groups (P<0.001); however, there was no significant difference in the chronic group (P>0.05). Concerning the validity of SWV as a predictor of acute and subacute ATFL injury, the receiver operator characteristics curve analysis showed that the best cut-off point for SWV was 6.165 m/s, with 84.3% sensitivity, 88.5% specificity, and an area under the curve of 0.93 (95% CI, 0.90-0.95).

Conclusions

VTIQ is a reliable sonographic method for detecting acute and subacute ATFL type I injury.

Intelligent localization and quantitative evaluation of anterior talofibular ligament injury using magnetic resonance imaging of ankle

Background

There is a high incidence of injury to the lateral ligament of the ankle in daily living and sports activities. The anterior talofibular ligament (ATFL) is the most frequent types of ankle injuries. It is of great clinical significance to achieve intelligent localization and injury evaluation of ATFL due to its vulnerability.

Methods

According to the specific characteristics of bones in different slices, the key slice was extracted by image segmentation and characteristic analysis. Then, the talus and fibula in the key slice were segmented by distance regularized level set evolution (DRLSE), and the curvature of their contour pixels was calculated to find useful feature points including the neck of talus, the inner edge of fibula, and the outer edge of fibula. ATFL area can be located using these feature points so as to quantify its first-order gray features and second-order texture features. Support vector machine (SVM) was performed for evaluation of ATFL injury.

Results

Data were collected retrospectively from 158 patients who underwent MRI, and were divided into normal (68) and tear (90) group. The positioning accuracy and Dice coefficient were used to measure the performance of ATFL localization, and the mean values are 87.7% and 77.1%, respectively, which is helpful for the following feature extraction. SVM gave a good prediction ability with accuracy of 93.8%, sensitivity of 88.9%, specificity of 100%, precision of 100%, and F1 score of 94.2% in the test set.

Conclusion

Experimental results indicate that the proposed method is reliable in diagnosing ATFL injury. This study may provide a potentially viable method for aided clinical diagnoses of some ligament injury.

Ankle Stability and Movement Coordination Impairments: Lateral Ankle Ligament Sprains Revision 2021

This revised clinical practice guideline (CPG) addresses the distinct but related lower extremity impairments of those with a first-time lateral ankle sprain (LAS) and those with chronic ankle instability (CAI). Depending on many factors, impairments may continue following injury. While most individuals experience resolution of symptoms, complaints of instability may continue and are defined as CAI. The aims of the revision were to provide a concise summary of the contemporary evidence since publication of the original guideline and to develop new recommendations or revise previously published recommendations to support evidence-based practice. J Orthop Sports Phys Ther 2021;51(4):CPG1-CPG80. doi:10.2519/jospt.2021.0302.