Injury of the tibiofibular syndesmosis: value of MR imaging for diagnosis

Value of arthroscopy in the management of acute lesions of the distal tibiofibular joint

PURPOSE

Managing the distal tibiofibular (DTF) joint remains a challenge despite recent developments. Ankle arthroscopy is emerging as a diagnostic and therapeutic means. Our study aimed to compare preoperative imaging data and arthroscopic data, with the hypothesis that imaging alone is insufficient to evaluate acute laxity, and with arthroscopy as the reference examination.

METHODS

All patients treated in 2023 in our department for an acute isolated DTF lesion were included prospectively. Preoperative radiographic and MRI imaging were compared with arthroscopic data.

RESULTS

Ten patients were treated. For five patients, the instability was doubtful after carrying out an appropriate imaging assessment (X-rays of both ankles, MRI). For four of these five patients, instability was confirmed by arthroscopy. Arthroscopy was useful for suturing the anterior bundle of the DTF joint for two patients and allowed for verifying the reduction in the sagittal and coronal planes for two patients. No complications were detected.

CONCLUSIONS

Arthroscopy in isolated acute DTF lesions seems to provide a diagnostic and therapeutic advantage. Its use may allow for exhaustive assessment and complete repair of lesions. It must be offered as soon as possible; a delay in specialized imaging may delay therapeutic care.

Bilateral External Torque CT Reliably Detects Syndesmotic Lesions in an Experimental Cadaveric Study

BACKGROUND

If tibiofibular syndesmotic injury is undetected, chronic instability may lead to persistent pain and osteoarthritis. So far, no reliable diagnostic method has been available. The primary objectives of this study were to determine whether defined lesions of the syndesmosis can be correlated with specific tibiofibular joint displacements caused by external rotational torque and to compare the performance of bilateral external torque computed tomography (BET-CT) and arthroscopy. Secondary objectives included an evaluation of the reliability of CT measurements and the suitability of the healthy contralateral ankle as a reference.

METHODS

Seven pairs of healthy, cadaveric lower legs were tested and assigned to 2 groups: (1) supination-external rotation (SER) and (2) pronation-external rotation (PER). In the intact state and after each surgical step, an ankle arthroscopy and 3 CT scans were performed. During the scans, the specimens were placed in an external torque device with 2.5, 5.0, and 7.5 Nm of torque applied.

RESULTS

The arthroscopic and CT parameters showed significant correlations in all pairwise comparisons. The receiver operating characteristic (ROC) curve analyses yielded the best prediction of syndesmotic instability with the anterior tibiofibular distance on CT, with a sensitivity of 84.1% and a specificity of 95.2% (area under the curve [AUC], 94.8%; 95% confidence interval [CI], 0.916 to 0.979; p < 0.0001) and with the middle tibiofibular distance on arthroscopy, with a sensitivity of 76.2% and specificity of 92.3% (AUC, 91.2%; 95% CI, 0.837 to 0.987; p < 0.0001). Higher torque amounts increased the rate of true-positive results.

CONCLUSIONS

BET-CT reliably detects experimental syndesmotic rotational instability, compared with the healthy side, with greater sensitivity and similar specificity compared with the arthroscopic lateral hook test. Translation of these experimental findings to clinical practice remains to be established.

LEVEL OF EVIDENCE

Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Normal Values for Distal Tibiofibular Syndesmotic Space With and Without Subject-Driven External Rotation Stress

BACKGROUND

The diagnosis and treatment of distal tibiofibular syndesmosis (DTFS) injury can be challenging, especially in cases of subtle instability that may be masked on 2-dimensional conventional radiographs. Weightbearing computed tomography (WBCT) has recently emerged as a useful diagnostic tool allowing direct assessment of distal tibiofibular area widening. The purpose of the current study was to examine and report normal threshold values for DTFS area measurements in a cohort of healthy volunteers, assessing the ankles in natural weightbearing position and under subject-driven external rotation stress.

METHODS

In this prospective study, we enrolled 25 healthy volunteers without a history of DTFS injury or high ankle sprain, previous foot and ankle surgery, or current ankle pain. Subjects with any prior ankle injuries were excluded. Study participants underwent bilateral standing nonstress and external rotation stress WBCT scans. The DTFS area (mm2) was semiautomatically quantified on axial-plane WBCT images 1 cm proximal to the apex of the talar dome using validated software. Syndesmosis area values were compared between "unstressed" and "stressed" ankles, as well as left and right ankles. Statistical analysis was performed using independent t tests/Wilcoxon analysis with statistical significance defined as P <.05.

RESULTS

The study cohort consisted of 50 ankles in 25 patients (12 males, 48%) with a mean age of 28.7 ± 9.3 years. In the unstressed ankle, the mean pooled DTFS area was determined to be 103.8 + 20.8 mm2. The mean syndesmosis area of unstressed left ankles (104.2 + 19.5 mm2) was similar to unstressed right ankles (109.2 + 17.2 mm2) in the cohort (P = .117). With external rotation stress, the DTFS area of left ankles (mean difference -0.304 mm2, CI -12.1 to 11.5; P = .082), right ankles (mean difference -5.5 mm2, CI 16.7-5.7; P = .132), and all ankles (mean difference -2.9 mm2, CI -10.8 to 5.1; P = .324) remained similar.

CONCLUSION

This study presents normal values and range for DTFS area calculation. In uninjured ankles with expected intact ligaments, subject-driven external rotation stress did not result in significant widening of the DTFS space as imaged on with WBCT.

LEVEL OF EVIDENCE

Level II, cross-sectional study.

Patterns of ankle injury in soccer: MRI clues to traumatic mechanism

Understanding the traumatic mechanisms of ankle injuries in soccer is crucial for an accurate and complete MRI diagnosis. Many ankle injuries share universal mechanisms seen in other athletic activities, but certain patterns are found to be more specific and relatively unique to soccer. Ankle impingement syndromes encountered in soccer encompass a spectrum of disorders that include anterior and posterior impingement categories, with anterior impingement representing pathology relatively specific to soccer. Lateral ligamentous sprains are one of the most common injuries; however, there is a higher rate of injuries to the medial structures in soccer as compared to other sports. Ankle fractures are uncommon in soccer while bone contusions and chondral and osteochondral injuries frequently accompany ligamentous sprains. Tendon abnormalities in soccer most commonly result from overuse injuries and typically affect peroneal tendons, posterior and anterior tibialis tendons, and Achilles tendon. Acute Achilles tendon ruptures occur in both recreational players and elite soccer athletes. Tibialis anterior friction syndrome may mimic tibial stress fractures. Long-term sequelae of acute traumatic and chronic overuse ankle injuries in professional soccer players manifest as ankle osteoarthritis that is more prevalent compared to not only the general population, but also to former elite athletes from other sports. This article examines the most common and specific injuries in soccer in order of their frequency.

Combining radiographic and CT measurements to rival MRI for the diagnosis of acute isolated syndesmotic injury

BACKGROUND

Acute isolated syndesmotic injuries (AISIs) have a high potential to be misdiagnosed or underdiagnosed at initial presentation to the hospital. Although magnetic resonance imaging (MRI) is the gold standard in noninvasive diagnostics, it is not always available immediately and is much more expensive than other imaging modalities. This study identifies improvements in conventional radiography and computed tomography (CT) to diagnose AISI and aims to reduce the number of MRI scans needed to verify the diagnosis.

METHODS

A retrospective case match control study was conducted by searching our trauma database between 2008 and 2022. A study group of patients with AISI (n = 64) and a control group of patients without AISI (n = 76) were formed to generate an equal number of images from both groups (62 radiographs and 22 CT scans). A total of 16 parameters that quantify the distal tibiofibular relation in injured and uninjured ankles were analyzed. For statistical analysis, a two-sided t-test was applied to calculate significant differences (p < 0.05). In a further step, a receiver operating characteristic curve (ROC) was used to determine cut-off values for the most significant parameters.

RESULTS

The most significant measurement (p < 0.001) on axial CT scans was the syndesmotic area (SA). The ROC curve revealed an area under the curve (AUC) of 0.94 (95% CI 0.86-1.0) and a cut-off value of 71.68 mm2 that shows a sensitivity and specificity of 95.5% and 81.8%, respectively.

CONCLUSION

This study suggests that radiographic imaging could represent an equally accurate alternative to MRI. These methods might generate the correct diagnosis faster due to their availability and inexpensiveness. By applying our new cut-off values in a clinical setting, the number of underdiagnosed and untreated unstable syndesmotic injuries could be reduced.

LEVEL OF EVIDENCE

III, retrospective comparative study.

Multiaxial 3D MRI of the Ankle: Advanced High-Resolution Visualization of Ligaments, Tendons, and Articular Cartilage

MRI is a valuable tool for diagnosing a broad spectrum of acute and chronic ankle disorders, including ligament tears, tendinopathy, and osteochondral lesions. Traditional two-dimensional (2D) MRI provides a high image signal and contrast of anatomic structures for accurately characterizing articular cartilage, bone marrow, synovium, ligaments, tendons, and nerves. However, 2D MRI limitations are thick slices and fixed slice orientations. In clinical practice, 2D MRI is limited to 2 to 3 mm slice thickness, which can cause blurred contours of oblique structures due to volume averaging effects within the image slice. In addition, image plane orientations are fixated and cannot be changed after the scan, resulting in 2D MRI lacking multiplanar and multiaxial reformation abilities for individualized image plane orientations along oblique and curved anatomic structures, such as ankle ligaments and tendons. In contrast, three-dimensional (3D) MRI is a newer, clinically available MRI technique capable of acquiring high-resolution ankle MRI data sets with isotropic voxel size. The inherently high spatial resolution of 3D MRI permits up to five times thinner (0.5 mm) image slices. In addition, 3D MRI can be acquired image voxel with the same edge length in all three space dimensions (isotropism), permitting unrestricted multiplanar and multiaxial image reformation and postprocessing after the MRI scan. Clinical 3D MRI of the ankle with 0.5 to 0.7 mm isotropic voxel size resolves the smallest anatomic ankle structures and abnormalities of ligament and tendon fibers, osteochondral lesions, and nerves. After acquiring the images, operators can align image planes individually along any anatomic structure of interest, such as ligaments and tendons segments. In addition, curved multiplanar image reformations can unfold the entire course of multiaxially curved structures, such as perimalleolar tendons, into one image plane. We recommend adding 3D MRI pulse sequences to traditional 2D MRI protocols to visualize small and curved ankle structures to better advantage. This article provides an overview of the clinical application of 3D MRI of the ankle, compares diagnostic performances of 2D and 3D MRI for diagnosing ankle abnormalities, and illustrates clinical 3D ankle MRI applications.

[Ligamentous injuries of the ankle joint : Importance of radiological imaging procedures]

Injuries of the ankle joint show lesions of the lateral ligamentous apparatus with an incidence of 1 in 1000 cases. With a range of 0.3-0.7 in 1000 cases, injuries of the medial ligamentous apparatus occur more frequently than previously thought and are often overlooked. Correct imaging diagnostics of the ankle ligaments are mandatory for the prognosis and treatment planning. In cases of clinically strong suspicion of ligamentous injury or osteochondral lesions of the ankle joint, after primary radiographic evaluation magnetic resonance imaging (MRI) is primarily recommended for a more precise assessment. Additionally, the sensitivity for assessment of the ligaments with ultrasonography is good (91% vs. 97% with MRI) but its specificity is inferior compared to MRI (63% vs. 93% with MRI). Supination trauma is the most common ankle injury and attention should be paid to the anterior tibiofibular ligament and calcaneofibular ligament. In approximately 50%, injuries to the superficial layer of the medial collateral ligament complex are associated with lesions of the posterior tibiotalar ligament.

[Ligamentous injuries of the ankle joint : Importance of radiological imaging procedures]

Injuries of the ankle joint show lesions of the lateral ligamentous apparatus with an incidence of 1 in 1000 cases. With a range of 0.3-0.7 in 1000 cases, injuries of the medial ligamentous apparatus occur more frequently than previously thought and are often overlooked. Correct imaging diagnostics of the ankle ligaments are mandatory for the prognosis and treatment planning. In cases of clinically strong suspicion of ligamentous injury or osteochondral lesions of the ankle joint, after primary radiographic evaluation magnetic resonance imaging (MRI) is primarily recommended for a more precise assessment. Additionally, the sensitivity for assessment of the ligaments with ultrasonography is good (91% vs. 97% with MRI) but its specificity is inferior compared to MRI (63% vs. 93% with MRI). Supination trauma is the most common ankle injury and attention should be paid to the anterior tibiofibular ligament and calcaneofibular ligament. In approximately 50%, injuries to the superficial layer of the medial collateral ligament complex are associated with lesions of the posterior tibiotalar ligament.

High-Ankle Sprain and Syndesmotic Instability: How Far Have We Come with Diagnosis and Treatment?

Probably one of the most controversial subjects in the orthopedic field is the distal tibiofibular articulation. Even though its most primary knowledge can be a matter of enormous debate, it is in the diagnosis and treatment most of the disagreements reign. Distinguishing between injury and instability remains challenging as well as an optimal clinical decision regarding surgical intervention. The last years presented technology and that was able to bring body to an already well-developed scientifical rationale. In this review article, we aim to demonstrate the current data behind syndesmotic instability in the ligament scenario, whereas using few fracture concepts.

Ligament Ruptures in Ankle Fractures-Was Lauge-Hansen Right?

The contribution of Lauge-Hansen to the understanding and treatment of ankle fractures cannot be underestimated, an unquestionable merit being the analysis of the ligamentous component of these injuries that are considered as equivalent to the respective malleolar fractures. In numerous clinical and biomechanical studies, the lateral ankle ligaments are ruptured either together with or instead of the syndesmotic ligaments, as predicted by the Lauge-Hansen stages. A ligament-based view on malleolar fractures may deepen the understanding of the mechanism of injury and lead to a stability-based evaluation and treatment of the 4 osteoligamentous pillars (malleoli) at the ankle.

MRI in Acute Ankle Sprains: Should We Be More Aggressive with Indications?

Acute ankle sprains are common sports injuries. MRI is the most accurate test for assessing the integrity and severity of ligament injuries in acute ankle sprains. However, MRI may not detect syndesmotic and hindfoot instability, and many ankle sprains are treated conservatively, questioning the value of MRI. In our practice, MRI adds value in confirming the absence or presence of ankle sprain-associated hindfoot and midfoot injuries, especially when clinical examinations are challenging, radiographs are inconclusive, and subtle instability is suspected. This article reviews and illustrates the MRI appearances of the spectrum of ankle sprains and associated hindfoot and midfoot injuries.

Ankle Sprains in Athletes: Current Epidemiological, Clinical and Imaging Trends

Purpose

Ankle injuries are frequent sports injuries. Despite optimizing treatment strategies during recent years, the percentage of chronification following an ankle sprain remains high. The purpose of this review article is, to highlight current epidemiological, clinical and novel advanced cross-sectional imaging trends that may help to evaluate ankle sprain injuries.

Methods

Systematic PubMed literature research. Identification and review of studies (i) analyzing and describing ankle sprain and (ii) focusing on advanced cross-sectional imaging techniques at the ankle.

Results

The ankle is one of the most frequently injured body parts in sports. During the COVID-19 pandemic, there was a change in sporting behavior and sports injuries. Ankle sprains account for about 16-40% of the sports-related injuries. Novel cross-sectional imaging techniques, including Compressed Sensing MRI, 3D MRI, ankle MRI with traction or plantarflexion-supination, quantitative MRI, CT-like MRI, CT arthrography, weight-bearing cone beam CT, dual-energy CT, photon-counting CT, and projection-based metal artifact reduction CT may be introduced for detection and evaluation of specific pathologies after ankle injury. While simple ankle sprains are generally treated conservatively, unstable syndesmotic injuries may undergo stabilization using suture-button-fixation. Minced cartilage implantation is a novel cartilage repair technique for osteochondral defects at the ankle.

Conclusion

Applications and advantages of different cross-sectional imaging techniques at the ankle are highlighted. In a personalized approach, optimal imaging techniques may be chosen that best detect and delineate structural ankle injuries in athletes.

Current status of the management of isolated syndesmotic injuries in Germany

INTRODUCTION

Although non-fracture-related syndesmotic injuries of the ankle are relatively rare, they may lead to poor clinical outcome if initially undiagnosed or managed improperly. Despite a variety of literature regarding possibilities for treatment of isolated syndesmotic injuries, little is known about effective applications of different therapeutic methods in day-to-day work. The aim of this study was to assess the current status of the treatment of isolated syndesmotic injuries in Germany.

MATERIALS AND METHODS

An online-questionnaire, capturing the routine diagnostic workup including clinical examination, radiologic assessment and treatment strategies, was sent to all members of the German Society of Orthopedic Surgery and Traumatology (DGOU) and Association of Arthroscopic and Joint Surgery (AGA). Statistical analysis was performed using Microsoft excel and SPSS.

RESULTS

Each question of the questionnaire was on average answered by 431 ± 113 respondents. External rotation stress test (66%), squeeze test (61%) and forced dorsiflexion test (40%) were most commonly used for the clinical examination. In the diagnostic workup, most clinicians relied on MRI (83%) and conventional X-ray analysis (anterior-posterior 58%, lateral 41%, mortise view 38%). Only 15% of the respondents stated that there is a role for arthroscopic evaluation for the assessment of isolated syndesmotic injuries. Most frequently used fixation techniques included syndesmotic screw fixation (80%, 42% one syndesmotic screw, 38% two syndesmotic screws), followed by suture-button devices in 13%. Syndesmotic screw fixation was mainly performed tricortically (78%). While 50% of the respondents stated that syndesmotic screw fixation and suture-button devices are equivalent in the treatment of isolated syndesmotic injuries with respect to clinical outcome, 36% answered that syndesmotic screw fixation is superior compared to suture-button devices.

CONCLUSIONS

While arthroscopy and suture-button devices do not appear to be widely used, syndesmotic screw fixation after diagnostic work-up by MRI seems to be the common treatment algorithm for non-fracture-related syndesmotic injuries in Germany.

Imaging of Acute Ankle and Foot Sprains

Ankle and foot injuries are very common injuries in the general population, and more so in athletes. MR imaging is the optimal modality to evaluate for ligamentous injuries of the ankle and associated conditions after ankle sprain. In this article, the authors discuss the epidemiology, biomechanics, normal anatomy, and pathology of the ankle as well as injuries of the hindfoot and midfoot that are often associated with ankle injuries.

Diagnostic Accuracy of Conventional Ankle CT Scan With External Rotation and Dorsiflexion in Patients With Acute Isolated Syndesmotic Instability

BACKGROUND

Syndesmotic injury in an athletic population is associated with a prolonged ankle disability after an ankle sprain and often requires a longer recovery than a lateral collateral ligament injury. Although several imaging tests are available, diagnosing syndesmotic instability remains challenging.

PURPOSE

To determine the diagnostic accuracy of conventional ankle computed tomography (CT) scans with the joint in external rotation and dorsiflexion and compare it with that of conventional ankle CT scans in a neutral position.

STUDY DESIGN

Cohort study (Diagnosis); Level of evidence, 2.

METHODS

Between September 2018 and April 2021, this prospective study consecutively included adults visiting the foot and ankle outpatient clinic with a positive orthopaedic examination for acute syndesmotic injury. Participants underwent 3 CT scan tests. First, ankles were scanned in a neutral position. Second, ankles were scanned with 45° of external rotation, dorsiflexion, and extended knees. Third, ankles were scanned with 45° of external rotation, dorsiflexion, and flexed knees. Three measurements, comprising rotation (measurement a), lateral translation (measurement c), and anteroposterior translation (measurement f) of the fibula concerning the tibia, were used to diagnose syndesmotic instability in the 3 CT scans. Magnetic resonance imaging was used as a reference standard. The area under the curve (AUC) was used to compare the diagnostic accuracy, and Youden's J index was calculated to determine the ideal cutoff point.

RESULTS

Images obtained in 68 participants (mean age, 36.5 years; range, 18-69 years) were analyzed, comprising 36 syndesmotic injuries and 32 lateral collateral ligament injuries. The best diagnostic accuracy occurred with the rotational measurement a, in which the second and third CT scans with stress maneuvers presented greater AUCs (0.97 and 0.99) than did the first CT scan in a neutral position (0.62). The ideal cutoff point for the stress maneuvers was 1.0 mm in the rotational measurement a and reached a sensitivity and specificity of 83% and 97% for the second CT scan with extended knees and 86% and 100% for the third CT scan with flexed knees, respectively. The ideal cutoff point for the first CT scan with a neutral position was 0.7 mm in the rotational measurement a, with a sensitivity of 25% and specificity of 97%.

CONCLUSION

Conventional ankle CT with stress maneuvers has excellent performance for diagnosing subtle syndesmotic rotational instability, as it shows a greater AUC and enhanced sensitivity at the ideal cutoff point compared with ankle CT in the neutral position.

Augmented stress weightbearing CT for evaluation of subtle tibiofibular syndesmotic injuries in the elite athlete

OBJECTIVE

We aim to present a novel imaging technique utilizing weight-bearing CT with syndesmotic stress to identify subtle, unstable syndesmotic injuries. We illustrate this with a case presentation of such an injury in an elite athlete that ultimately required operative fixation.

MATERIALS AND METHODS

In order to perform an augmented stress weightbearing CT, the patient is in the standing position, feet facing forward, and with weight distributed equally. The patient is then coached to internally rotate the shin and knee. This places an external rotational moment on the TFS due to the planted foot and ankle. The augmented stress images undergo 3D reconstruction and post-processing to render coronal and sagittal images. These are subsequently compared to standard, conventional weightbearing CT images performed without the external rotation stress.

RESULTS

We illustrate this technique by presenting a case in which a 21-year-old collegiate athlete sustained a Grade II syndesmotic injury, diagnosed by MRI and clinical exam without evidence of instability by standard weightbearing CT or weightbearing radiographs. After undergoing the augmented stress weightbearing CT, the instability was noted. This prompted subsequent operative fixation and ultimately return to sport.

CONCLUSION

We propose this technique for diagnosing unrecognized, subtle dynamically unstable syndesmosis injuries where clinical suspicion persists despite negative imaging, particularly in the elite athlete.

The value of radiologic diagnostics in evaluating deltoid integrity in isolated type B ankle fractures: a systematic review of the literature

INTRODUCTION

Excluding deep deltoid ligament (DDL) rupture in isolated type B ankle fractures is crucial in the decision-making process for surgical or conservative treatment. There is no consensus about the most accurate radiologic diagnostic test to determine medial injury. The aim of this study is to systematically review the literature concerning radiologic diagnostics that evaluate medial injury in adult patients with isolated type B ankle fractures.

METHODS

The electronic databases PubMed, Embase, Web of Science, COCHRANE Library, and Emcare were searched to identify studies published from January 1990 to December 2020 concerning sensitivity and specificity of diagnostic tests that evaluate medial injury in patients with an isolated type B ankle fracture. For inclusion, comparison to a reference test was required to provide results in terms of sensitivity, specificity, and preferably positive predictive value and negative predictive value RESULTS: This review included 8 studies. Ultrasound showed the highest sensitivity of 100% and a specificity between 90 and 100% for detecting DDL rupture. Gravity stress radiographs showed a sensitivity of 71-100% and a specificity between 88 and 92%. The mortise, external rotation stress test, and MRI had lower sensitivity and specificity values, between 65 and 88%.

CONCLUSION

The most accurate and available methods for diagnosing deltoid integrity seem to be the ultrasound and the GS radiograph. Further research is needed to confirm the results of this review.

Which test is the best? An updated literature review of imaging modalities for acute ankle diastasis injuries

Ankle diastasis injuries, or ankle syndesmotic injuries, are common among athletes who usually experience a traumatic injury to the ankle. Long‐term complications are avoidable when these injuries are diagnosed promptly and accurately treated. Whilst ankle arthroscopy remains the gold standard diagnostic modality for ankle diastasis injuries, imaging modalities are still widely utilised due to the treatment having greater accessibility, being less invasive and the most cost effective. There are various imaging modalities used to diagnose diastasis injuries, varying in levels of specificity and sensitivity. These observation methods include; X‐ray, computed tomography (CT), magnetic resonance imaging (MRI) and ankle arthroscopy. This article uncovers common criteria and parameters to diagnose diastasis injuries through the implementation of different imaging modalities. The conclusions addressed within this article are deduced from a total of 338 articles being screened with only 43 articles being selected for the purposes of this examination. Across most articles, it was concluded that that plain X‐ray should be used in the first instance due to its wide availability, quick processing time, and low cost. CT is the next recommended investigation due to its increased sensitivity and specificity, ability to show the positional relationship of the distal tibiofibular syndesmosis, and reliability in detecting minor diastasis injuries. MRI is recommended when ankle diastasis injuries are suspected, but not diagnosed on previous imaging modalities. It has the highest sensitivity and specificity compared to X‐ray and CT.

The prevalence of posterior inferior tibiofibular ligament and inferior tibiofibular transverse ligament injuries in syndesmosis-injured ankles evaluated by oblique axial magnetic resonance imaging: a retrospective study

Background

Transverse ligament and posterior inferior tibiofibular ligament injuries have not been investigated till date because these are difficult to evaluate using standard magnetic resonance imaging. This study aimed to investigate the prevalence of transverse ligament and posterior inferior tibiofibular ligament injuries in syndesmosis-injured ankles using oblique axial magnetic resonance imaging.

Methods

The patients who were diagnosed with syndesmosis injury using magnetic resonance imaging (MRI) within 7 days of the trauma were included. Patients with concomitant fractures were excluded. A total of 34 patients (1 woman and 33 men) with an average age of 22 years (range, 14–64 years) were included. The anterior inferior tibiofibular, interosseous, transverse, and posterior inferior tibiofibular ligaments were classified as intact, partial tear, or complete tear using usual axial and oblique axial MRIs.

Results

There were 8 (23.5%) ankles with an intact, 21 (61.8%) ankles with a partially torn, and 5 (14.7%) ankles with a complete tear of transverse ligament. There were 20 (58.8%) ankles with an intact, 12 (35.3%) ankles with a partially torn, and 2 (5.9%) ankles with a complete tear of posterior inferior tibiofibular ligament. Overall, 50% of the transverse ligament injuries occurred without posterior inferior tibiofibular ligament involvement.

Conclusions

The oblique axial magnetic resonance imaging scan revealed that the prevalence of transverse ligament and posterior inferior tibiofibular ligament injuries in syndesmosis-injured ankles were 76.5 and 41.2%, respectively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05220-0.

Syndesmotic instability can be assessed by measuring the distance between the tibia and the fibula using an ultrasound without stress: a cadaver study

Background

Ultrasound examinations for syndesmosis injury might be useful for the quantitative evaluation of syndesmotic instability. The purpose of this study was to evaluate the efficacy of ultrasound assessment by measuring the tibiofibular distance of syndesmosis injuries in various ligament-injured models and stress load conditions.

Methods

Five normal ankles from Thiel-embalmed cadavers were used. Ultrasound assessment was performed by placing a probe in parallel with the ligament running just above the anterior inferior tibiofibular ligament (AITFL). The distance between the anterior border of the tibia and the fibula was measured in the intact condition. Next, Bassett’s ligament was cut arthroscopically to reduce damage to soft tissues as much as possible and measurement was performed in the same way. After that, the AITFL, interosseous membrane (IOM), deltoid ligament, and posterior inferior tibiofibular ligament (PITFL) were macroscopically cut and measured in that order. Ankle positions were without stress (natural plantar flexion without applying stress to the ankle joint), dorsiflexion stress, inversion stress, and external rotation stress. All stress to the ankle joint was carried out manually to the maximum extent.

Results

As with the without-stress condition, significant increases in tibiofibular distances after AITFL dissection were seen compared with the intact state under all stress conditions (intact: 4.9 ± 1.0 mm without stress, 5.6 ± 1.2 mm with dorsiflexion, 5.9 ± 1.0 mm with inversion, and 6.7 ± 1.3 mm with external rotation; AITFL dissection: 6.7 ± 1.5 mm without stress, 7.3 ± 1.2 mm with dorsiflexion, 7.5 ± 1.4 mm with inversion, and 8.7 ± 1.6 mm with external rotation). AITFL dissection with external rotation stress significantly increased the tibiofibular distance compared to without stress.

Conclusion

Changes in tibiofibular distance with the severity of syndesmosis injury were measured by ultrasound using cadavers. No significant change was seen with Bassett’s ligament injury, but tibiofibular distance increased significantly with injuries of equal to or greater severity than AITFL injury. Results were similar not only for external rotation stress, but also for dorsiflexion stress and inversion stress, and even in unloaded states, significant tibiofibular widening was confirmed with injuries of equal to or greater severity than AITFL injury.

Imaging Review of Snowboard Injuries

Snowboarding and skiing remain the two most popular winter sports worldwide. Musculoskeletal (MSK) injuries are common in snowboarding, and the number has increased significantly since the advent of snow parks. The number of injuries is the highest for novice snowboarders; more experienced boarders generally sustain more severe injuries. Snowboarders can experience a wide array of MSK injuries, but some injury types are more frequently encountered because of the specific injury mechanism unique to snowboarding. This article reviews the most common snowboarding injuries with a focus on the current understanding of the injury mechanism and provides an approach to imaging.

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.

3D MRI of the Ankle: A Concise State-of-the-Art Review

Magnetic resonance imaging (MRI) is a powerful imaging modality for visualizing a wide range of ankle disorders that affect ligaments, tendons, and articular cartilage. Standard two-dimensional (2D) fast spin-echo (FSE) and turbo spin-echo (TSE) pulse sequences offer high signal-to-noise and contrast-to-noise ratios, but slice thickness limitations create partial volume effects. Modern three-dimensional (3D) FSE/TSE pulse sequences with isotropic voxel dimensions can achieve higher spatial resolution and similar contrast resolutions in ≤ 5 minutes of acquisition time. Advanced acceleration schemes have reduced the blurring effects of 3D FSE/TSE pulse sequences by affording shorter echo train lengths. The ability for thin-slice partitions and multiplanar reformation capabilities eliminate relevant partial volume effects and render modern 3D FSE/TSE pulse sequences excellently suited for MRI visualization of several oblique and curved structures around the ankle. Clinical efficiency gains can be achieved by replacing two or three 2D FSE/TSE sequences within an ankle protocol with a single isotropic 3D FSE/TSE pulse sequence. In this article, we review technical pulse sequence properties for 3D MRI of the ankle, discuss practical considerations for clinical implementation and achieving the highest image quality, compare diagnostic performance metrics of 2D and 3D MRI for major ankle structures, and illustrate a broad spectrum of ankle abnormalities.

Sub-Acute Syndesmotic Injury: A Review and Proposed Treatment Algorithm

Sub-acute syndesmotic injuries are classified as from six weeks to six months from the initial injury date and can be considered a distinct group of patients; however, they are often mistreated and progress to chronic injuries with significant sequelae. The authors performed a comprehensive literature search on the MEDLINE database. The search yielded 165 studies up to January 2021, after the application of inclusion/exclusion criteria. This yielded 10 studies with a total of 156 relevant patients for review. We found that a delay in diagnosis is common and has a negative impact on outcomes. If a sub-acute syndesmotic injury is suspected and plain radiographs are inconclusive, magnetic resonance imaging is indicated if there is still an index of suspicion. Surgical intervention should aim to restore normal length and rotational alignment of the fibula whilst also addressing the need to debride tissues within the joint and syndesmosis. Syndesmosis must then be adequately reduced and stabilised with syndesmotic screw fixation, and augmentation with tendon/ligament reconstruction should be considered. All studies showed an average improvement in functional outcome measures post-operatively. The only study to compare sub-acute and chronic patients' functional outcomes post-operatively showed significant improvement in the sub-acute cohort; highlighting the importance of early intervention. We suggest a treatment algorithm that may help with the diagnosis and management of these injuries. We believe this will help all healthcare professionals to standardise care. Further research is required to assess sub-acute injury outcomes with tendon/ligamentous augmented reconstruction, as no level 1 or 2 studies currently exist.

Diagnosis of tibiofibular syndesmosis instability in Weber type B malleolar fractures

Objective

This study was performed to analyze the clinical value of X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) examinations for the diagnosis of distal tibiofibular syndesmosis injuries in Weber type B ankle fractures with reference to the ankle arthroscopic findings.

Methods

This retrospective clinical study involved 52 patients with type B ankle fractures from August 2014 to January 2018. We analyzed the patients’ preoperative imaging data and judged the stability of the distal tibiofibular syndesmosis using X-ray, CT, and MRI examinations. We also evaluated the syndesmosis stability with arthroscopy both statically and dynamically.

Results

With the arthroscopic findings as the standard, the sensitivity of X-ray for diagnosing syndesmosis instability was 52.8%, the specificity was 100%, and the diagnostic efficiency was 67.3%. The sensitivity of CT for diagnosing syndesmosis instability was 77.8%, the specificity was 100%, and the diagnostic efficiency was 84.6%. The sensitivity of MRI for diagnosing syndesmosis instability was 100%, the specificity was 81.3%, and the diagnostic efficiency was 94.2%.

Conclusion

This study suggests that an arthroscopic examination may be recommended when the X-ray or CT features are different from the MRI findings while diagnosing tibiofibular syndesmosis instability in Weber type B malleolar fractures.

Diagnostic accuracy of clinical tests assessing ligamentous injury of the ankle syndesmosis: A systematic review with meta-analysis

OBJECTIVE

To summarise and evaluate research on the diagnostic accuracy of clinical tests for ligamentous injury of the ankle syndesmosis.

METHODS

CINAHL, Embase, and MEDLINE were searched from inception to February 12, 2021. Studies comparing clinical examination to arthroscopy, magnetic resonance imaging, or ultrasound were considered eligible. Meta-analysis was based on random effect modelling and limited to studies fulfilling all QUADAS-2 criteria. Sensitivity (SN), specificity (SP) and likelihood ratios determined diagnostic accuracy, all with 95% confidence intervals (CI).

RESULTS

Six studies were included (512 participants; 13 clinical tests; 29% median prevalence). No individual test was associated with both high sensitivity and high specificity. Tests with the highest sensitivity were: palpation [SN 92% (95%CI 79-98)] and dorsiflexion lunge [SN 75% (95% CI 64-84%); n = 2 studies]. Tests with the highest specificity were: squeeze test [SP 85% (95% CI 81-89%); n = 4 studies] and external rotation [SP 78% (95% CI 73-82%); n = 4 studies].

CONCLUSIONS

Clinical examination should involve initial clustering of tests with high sensitivity (palpation; dorsiflexion lunge), followed by a test with high specificity (squeeze). However, as these tests cannot definitively stratify syndesmotic injuries into stable vs unstable, decisions on optimal management (conservative vs surgery) require additional imaging or arthroscopy.

Weightbearing Cone-Beam Computed Tomography of Acute Ankle Syndesmosis Injuries

Syndesmotic injuries are common, but only a subset of these injuries are unstable. A noninvasive tool for identifying instability would aid in the selection of patients for surgery. Weightbearing computed tomography (CT) data have been reported for healthy patients, but there are limited data on unstable syndesmoses. We evaluated the syndesmotic area of arthroscopically proven unstable ankles after acute injury. This is a prospective comparative study of consecutive patients recruited to a weightbearing CT database. Thirty-nine patients were included for analysis with arthroscopically proven unstable syndesmoses and an uninjured contralateral ankle. The syndesmosis area was measured for both ankles, in non-weightbearing and weightbearing positions, and compared. Syndesmosis area of the unstable ankle was significantly greater than the uninjured ankle of the same patient, by a mean of 22.9 ± 10.5 mm². This was a significantly greater difference than that observed with non-weightbearing CT (9.8 ± 10.2 mm², p < .001). Dynamic change in area, from non-weightbearing to weightbearing, of the unstable ankle (13.7% [16.6 ± 9.9 mm²]) was significantly greater than that of the uninjured ankle (3.1% [3.4 ± 6.7 mm²], p < .001). The intraobserver and interobserver correlations were good with intraclass correlation coefficients of 0.983 and 0.970, respectively. Weightbearing CT demonstrated significantly greater diastasis in unstable ankles than did conventional non-weightbearing CT. Syndesmosis area measurement was reliable and reproducible. Dynamic change in area and weightbearing comparison with the contralateral uninjured ankle are 2 parameters that may prove useful in the future for predicting syndesmotic 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.

Evaluation of ankle ligaments with CT: A feasibility study

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.

Diagnostic value of ultrasonography in acute lateral and syndesmotic ligamentous ankle injuries

Objectives

To determine the diagnostic value of ultrasonography for complete discontinuity of the anterior talofibular ligament (ATFL), the calcaneofibular ligament (CFL) and the anterior inferior tibiofibular ligament (AITFL).

Methods

All acute ankle injuries in adult athletes (> 18 years old) presenting to the outpatient department of a specialised Orthopaedic and Sports Medicine Hospital within 7 days post-injury were assessed for eligibility. Using ultrasonography, one musculoskeletal radiologist assessed the ATFL, CFL and AITFL for complete discontinuity. Dynamic ultrasound measurements of the tibiofibular distance (mm) in both ankles (injured and contralateral) were acquired in the neutral position (N), during maximal external rotation (Max ER), and maximal internal rotation (Max IR). MR imaging was used as a reference standard.

Results

Between October 2017 and July 2019, 92 acute ankle injuries were included. Ultrasound diagnosed complete discontinuity of the ATFL with 87% (CI 74–95%) sensitivity and 69% (CI 53–82%) specificity. Discontinuity of the CFL was diagnosed with 29% (CI 10–56%) sensitivity and 92% (CI 83–97%) specificity. Ultrasound diagnosed discontinuity of the AITFL with 100% (CI 74–100%) sensitivity and 100% (CI 95–100%) specificity. Of the dynamic measurements, the side-to-side difference in external rotation had the highest diagnostic value for complete discontinuity of the AITFL (sensitivity 82%, specificity 86%; cut-off 0.93 mm).

Conclusions

Ultrasound has a good to excellent diagnostic value for complete discontinuity of the ATFL and AITFL. Therefore, ultrasound can be used to screen for injury of the ATFL and AITFL. Compared with ultrasound, dynamic ultrasound has inferior diagnostic value for complete discontinuity of the AITFL.

Key Points

• Ultrasound has a good to excellent diagnostic value for complete discontinuity of the anterior talofibular ligament (ATFL) and anterior inferior tibiofibular ligament (AITFL).

• Ultrasound can be used to screen for injury of the ATFL and AITFL.

• Compared with ultrasound, dynamic ultrasound has inferior diagnostic value for complete discontinuity of the AITFL.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-07305-7) contains supplementary material, which is available to authorized users.

Comparison of External Torque to Axial Loading in Detecting 3-Dimensional Displacement of Syndesmotic Ankle Injuries

BACKGROUND

Current imaging techniques try to quantify 3-dimensional displacement of syndesmotic ankle injuries using 2-dimensional measurements, which may obscure an exact diagnosis. Therefore, our aim was to determine 3-dimensional displacement of syndesmotic ankle injuries under load and torque using a weightbearing computed tomography (WBCT) and to assess the relation with previously established 2-dimensional measurements.

METHODS

Seven paired cadaver specimens were mounted into a radiolucent frame. WBCT scans were obtained to generate 3-dimensional models after different patterns of axial load (0 kg, 85 kg) combined with external torque (0, 10 Nm). Sequential imaging was repeated in ankles containing intact syndesmotic ligaments, sectioning of the anterior inferior tibiofibular ligament (AITFL; condition 1A), deltoid ligament (DL; condition 1B), combined AITFL+DL (condition 2), and AITFl+DL+interosseous membrane (condition 3). Reference anatomical landmarks were established relative to the intact position of the fibula to quantify displacement. A subsequent correlation analysis was performed between the obtained 2- and 3-dimensional measurements.

RESULTS

Axial load increased lateral translation (mean = -0.9 mm, 95% confidence interval [CI]: 1.3, -0.1) significantly in condition 2 relative to the intact ankle (P < .05) but did not demonstrate other significant displacements. External torque increased displacement significantly in all directions (P < .05), except for dorsal translation of the fibula (P > .05). The highest displacement could be detected when external torque was applied in condition 3 and consisted of posterior translation (mean = -3.1 mm; 95% CI: -4.8, -2.7) and external rotation (mean = -4.7 degrees; 95% CI: -5.6, -2.9). Pearson correlation coefficients between the 2-dimensional and 3-dimensional measurements were moderate and ranged from 0.31 to 0.56 (P < .05).

CONCLUSION

External torque demonstrated superiority over axial load in detecting syndesmotic ankle instability. Axial load increased lateral translation; however, differences were submillimeter in magnitude until torque was applied. A moderate correlation was found with previously established 2-dimensional measurements.

CLINICAL RELEVANCE

In clinical practice these findings substantiate application of external torque in current imaging modalities to improve detection of syndesmotic ankle injuries.

Comparative CT with stress manoeuvres for diagnosing distal isolated tibiofibular syndesmotic injury in acute ankle sprain: a protocol for an accuracy- test prospective study

INTRODUCTION

Although several imaging options are available for diagnosing syndesmotic injury, a fundamental question that guides treatment remains unanswered. Syndesmotic instability is still challenging to diagnose correctly, and syndesmotic disruption and true syndesmotic instability should be differentiated. Currently, imaging tests quickly diagnose severe syndesmotic instability but have difficulty in diagnosing mild and moderate cases. This study aims to investigate which strategy among an existing CT index test and two new add-on CT index tests with stress manoeuvres more accurately diagnoses syndesmotic instability. The secondary objective is to investigate the participants' disability outcomes by applying the Foot and Ankle Ability Measure questionnaire.

METHODS AND ANALYSES

This study of a diagnostic accuracy test will consecutively select individuals older than 18 years with a clinical diagnosis of a suspected acute syndesmotic injury. Three strategies of the CT index test (one in the neutral position and two with stress) will examine the accuracy using MRI as the reference standard. The external rotation and dorsiflexion of the ankle will guide the stress manoeuvres. A comparison of measurements between the injured syndesmosis and the uninjured contralateral side of the same individual will investigate the syndesmotic instability, by evaluating the rotational and translational relationships between the fibula and tibia. Sensitivity, specificity, area under the receiver operating characteristic curve and likelihood analyses will compare the diagnostic accuracies of the strategies.

ETHICS AND DISSEMINATION

The Internal Review Board and the Einstein Ethics Committee approved this study (registered number 62100016.5.0000.0071). All participants will receive an oral description of the study's aim, and the choice to participate will be free and voluntary. Participants will be enrolled after they sign the written informed consent form, including the terms of confidentiality. The results will be presented at national and international conferences and published in peer-reviewed journals and social media.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04095598; preresults).

Acute and Chronic Syndesmotic Instability: Role of Surgical Stabilization

Acute and chronic syndesmotic injuries significantly impact athletic function and activities of daily living. Patient history, examination, and judicious use of imaging modalities aid diagnosis. Surgical management should be used when frank diastasis, instability, and/or chronic pain and disability ensue. Screw and suture-button fixation remain the mainstay of treatment of acute injuries, but novel syndesmotic reconstruction techniques hold promise for treatment of acute and chronic injuries, especially for athletes. This article focuses on anatomy, mechanisms of injury, diagnosis, and surgical reduction and stabilization of acute and chronic syndesmotic instability. Fixation methods with a focus on considerations for athletes are discussed.

Utility of Volumetric Measurement via Weight-Bearing Computed Tomography Scan to Diagnose Syndesmotic Instability

BACKGROUND

Weight-bearing computed tomography (WBCT) allows evaluation of the distal syndesmosis under physiologic load. We hypothesized that WBCT volumetric measurement of the distal syndesmosis would be increased on the injured as compared to the contralateral uninjured side and that these 3-dimensional (3D) calculations would be a more sensitive determinant than 2-dimensional (2D) methodology among patients with syndesmotic instability.

METHODS

Twelve patients with unilateral syndesmotic instability requiring operative fixation who underwent preoperative bilateral foot and ankle WBCT were included in the study group. The control group consisted of 24 patients without ankle injury who underwent similar imaging. On WBCT scan, 2D measurements of the syndesmosis joint were first measured 1 cm above the joint line in the axial plane via syndesmotic area and distances between the anterior, middle, and posterior quadrants. Thereafter, comparative 3D volumetric measurements of the syndesmotic joint were also calculated: (1) from the tibial plafond extending until 3 cm proximally, (2) 5 cm proximally, and (3) 10 cm proximally.

RESULTS

In patients with unilateral syndesmotic instability, all 3 weight-bearing volumetric measurements were significantly larger on the injured side as compared to the contralateral, uninjured side (P < .001). In the control group, there was no difference between syndesmotic volumes at any level. Of these 3 anatomic reference points, the 3D measurement spanning from the tibial plafond to a level 5 cm proximally had the highest relative volumetric ratio between the injured and uninjured side, suggesting it is the most sensitive in distinguishing between stable and unstable syndesmotic injury (P < .001). Notably, this 3D volumetric measurement was also more sensitive than 2D measurements (P = .001).

CONCLUSION

3D volumetric measurement of the syndesmosis joint appears to be the most effective way to diagnose syndesmotic instability, compared with more traditional 2D syndesmosis measurement.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

A cadaveric study investigating the role of the anterior inferior tibio-fibular ligament and the posterior inferior tibio-fibular ligament in ankle fracture syndesmosis stability

BACKGROUND

This cadaveric study aimed to investigate the role AITFL and PITFL have on preventing talar shift in ankle fractures, as well as investigating the role of AITFL reconstruction in preventing talar shift.

METHODS

Twelve lower limb cadavers were used. Talar shift was measured following: Step 1- no ligaments cut; Step 2- entire deltoid ligament division; Step 3- group A (5 specimens) PITFL cut whilst group B (7 specimens) AITFL cut; Step 4- group A had AITFL divided whilst group B had PITFL cut. Reconstruction of the AITFL was performed using part of the superior extensor retinaculum as a local flap. Measurement of talar shift was then repeated.

RESULTS

With no ligaments divided, mean talar shift was 0.8mm for group A and 0.7mm for group B. When the deltoid ligament was divided, mean talar shift for group A was 4.8mm compared to 4.7mm in group B (P=1.00). The mean shift in group A after PITFL division was 6.0mm, increasing the talar shift by an average of 1.2mm. In group B after AITFL division mean talar shift was 8.3mm (P=0.06), increasing talar shift by an average of 3.6mm. After division of the second tibiofibular ligament, mean talar shift in group A measured 10.0mm and in group B was 10.9mm (P=0.29). Three times more talar shift occurred after the AIFTL was divided compared to the PITFL (P=0.06).

CONCLUSION

Consequently, repairing the PITFL in isolation (for example by fixation of a posterior malleolus avulsion fracture) may not adequately prevent talar shift; we feel consideration should also be given to reconstruction of the AITFL to augment the syndesmosis fixation, which may provide a stronger restoration of ankle stability.

LEVEL OF CLINICAL EVIDENCE

5.

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.

Optimization of MRI Protocol for the Musculoskeletal System

자기공명영상(magnetic resonance imaging; 이하 MRI)은 다른 영상 기법에 비해 연부 조직 대조도와 해상력이 높아 근골격계 영역에서 중요한 진단 기기로 이용되고 있다. 최근 MRI 관련 기술이 발달함에 따라 빠른 영상 촬영 및 다양한 영상면 재구성이 가능해짐으로써 입체적인 근골격계 해부학적 구조와 병변을 더욱 잘 평가할 수 있게 되었다. 또한, MRI는 최적화 정도에 따라 영상의 질, 진단 정확도 및 촬영 시간 등이 달라지며, MRI 장치의 효율적 인 운용과도 관련이 있어, 이를 관리하는 것은 영상의학과 의사의 중요한 역할이다. 본 종설에서는 6개 주요 관절에 따른 환자 자세, radiofrequency 코일 선택, 권장 펄스열, 영상면 구성 및 스캔 파라미터에 대한 지침을 제시함으로써 근골격계 MRI의 최적화에 도움이 되고자 한다.

MRI of the distal tibiofibular joint

The distal tibiofibular joint is a fibrous joint that plays a crucial role in the stability of the ankle joint. It is stabilized by three main ligaments: the anterior inferior tibiofibular ligament, the posterior inferior tibiofibular ligament, and the interosseous tibiofibular ligament, which are well delineated on magnetic resonance imaging. Pathology of the distal tibiofibular joint is mostly related to trauma and the longer-term complications of trauma, such as soft tissue impingement, heterotopic ossification, and synostosis. This review article outlines the MRI anatomy and pathology of this joint.

The arthroscopic syndesmotic assessment tool can differentiate between stable and unstable ankle syndesmoses

PURPOSE

Patients with stable isolated injuries of the ankle syndesmosis can be treated conservatively, while unstable injuries require surgical stabilisation. Although evaluating syndesmotic injuries using ankle arthroscopy is becoming more popular, differentiating between stable and unstable syndesmoses remains a topic of on-going debate in the current literature. The purpose of this study was to quantify the degree of displacement of the ankle syndesmosis using arthroscopic measurements. The hypothesis was that ankle arthroscopy by measuring multiplanar fibular motion can determine syndesmotic instability.

METHODS

Arthroscopic assessment of the ankle syndesmosis was performed on 22 fresh above knee cadaveric specimens, first with all syndesmotic and ankle ligaments intact and subsequently with sequential sectioning of the anterior inferior tibiofibular ligament, the interosseous ligament, the posterior inferior tibiofibular ligament, and deltoid ligaments. In all scenarios, four loading conditions were considered under 100N of direct force: (1) unstressed, (2) a lateral hook test, (3) anterior to posterior (AP) translation test, and (4) posterior to anterior (PA) translation test. Anterior and posterior coronal plane tibiofibular translation, as well as AP and PA sagittal plane translation, were arthroscopically measured.

RESULTS

As additional ligaments of the syndesmosis were transected, all arthroscopic multiplanar translation measurements increased (p values ranging from p < 0.001 to p = 0.007). The following equation of multiplanar fibular motion relative to the tibia measured in millimeters: 0.76*AP sagittal translation + 0.82*PA sagittal translation + 1.17*anterior third coronal plane translation-0.20*posterior third coronal plane translation, referred to as the Arthroscopic Syndesmotic Assessment tool, was generated from our data. According to our results, an Arthroscopic Syndesmotic Assessment value equal or greater than 3.1 mm indicated an unstable syndesmosis.

CONCLUSIONS

This tool provides a more reliable opportunity in determining the presence of syndesmotic instability and can help providers decide whether syndesmosis injuries should be treated conservatively or operatively stabilized. The long-term usefulness of the tool will rest on whether an unstable syndesmosis correlates with acute or chronic clinical symptoms.

Diagnosis and treatment of tibiofibular syndesmosis lesions

The tibiofibular syndesmosis is a fibrous joint essential for ankle stability, whence the classical comparison with a mortise. Syndesmosis lesions are quite frequent in ankle trauma. This is a key element in ankle stability and lesions may cause pain or instability and, in the longer term, osteoarthritis. The lesions are often overlooked due to diagnostic difficulties, but collision sport with strong contact is the main culprit. Diagnosis, whether in the acute or the chronic phase, is founded on an association of clinical and paraclinical signs. Cross-sectional imaging such as MRI is fundamental to confirming clinical suspicion. Absence of tibiofibular diastasis no longer rules out the diagnosis. Stress CT and the introduction of weight-bearing CT are promising future diagnostic tools. Exhaustive osteo-ligamentous ankle assessment is necessary, as syndesmosis lesions may be just one component in more complex rotational instability. Therapeutically, arthroscopy and new fixation techniques, such as suture buttons, are opening up new perspectives, especially for chronic lesions (>6months). The present anatomic, epidemiological, diagnostic and therapeutic review does not preclude further clinical studies of rotational ankle instability with its strong risk of osteoarthritis.

High Ankle Sprains in Professional Ice Hockey Players: Prognosis and Correlation Between Magnetic Resonance Imaging Patterns of Injury and Return to Play

Background:

Hockey players sustain a greater incidence of ankle syndesmosis injuries than other athletes. These injuries have a higher morbidity and more unpredictable recovery than lateral ankle sprains. Magnetic resonance imaging (MRI) has been used to establish the diagnosis but has not been evaluated for its ability to predict return to play.

Hypothesis:

We hypothesized that patterns of injury defined on MRI could be used to predict return to play in a cohort of professional hockey players with syndesmosis sprains.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A prospectively collected National Hockey League (NHL) database was analyzed from the 2006-2007 to 2011-2012 seasons to assess return to play after an injury. A separate retrospective review of ankle MRI scans from professional hockey players with a documented high ankle sprain sustained between 2007 and 2012 was performed. Injuries were classified on MRI as complete or partial tears of the anterior-inferior tibiofibular ligament (AITFL), posterior-inferior tibiofibular ligament (PITFL), anterior talofibular ligament (ATFL), posterior talofibular ligament (PTFL), calcaneofibular ligament (CFL), and deltoid ligament. Fractures, bone contusions, and osteochondral lesions were also recorded.

Results:

A total of 105 NHL athletes sustained high ankle sprains over the 5 seasons studied. Of these athletes, 85 were unable to play and missed a median of 8 games (range, 0-65 games). A retrospective MRI evaluation of 21 scans identified complete AITFL tears in 13 (62%) and high-grade partial tears in 5 (24%) cases. In contrast, the PITFL was partially torn in 9 (43%) and normal in 12 (57%) cases. Bone contusions were seen in 71% of cases and lacked a consistent pattern. The most commonly associated ligamentous injury was of the ATFL, which was injured in 52% of cases (11/21; 3 complete and 8 partial). There was no difference in the mean number of days lost when players were stratified by patterns of injury (incomplete/complete AITFL tear ± additional ligamentous injury, bone contusion, syndesmosis width).

Conclusion:

A high ankle sprain resulted in significant variations in time of recovery among professional hockey players. A torn AITFL and bone bruising were the most common patterns of injury. Although MRI can be used to confirm the diagnosis of a syndesmosis injury, it did not predict return to play in this population.

Syndesmotic Ligaments of the Ankle: Anatomy, Multimodality Imaging, and Patterns of Injury

Injuries to the syndesmotic ligaments of the ankle or "high ankle sprains" are common in acute ankle trauma but can be difficult to diagnose both clinically and on imaging. Missed injuries to the syndesmosis can lead to chronic ankle instability, which can cause persistent pain and lead to early osteoarthritis. This review will illustrate the anatomy of the syndesmotic ligamentous complex, describe radiographic, CT, and MR imaging of the syndesmosis, demonstrate typical mechanisms of injuries and associated fracture patterns, and provide an overview of important management considerations.

MRI for high ankle sprains with an unstable syndesmosis: posterior malleolus bone oedema is common and time to scan matters

PURPOSE

Early clinical examination combined with MRI allows accurate diagnosis of syndesmosis instability after a high ankle sprain. However, patients often present late. The aims of the current study were to describe MRI characteristics associated with syndesmosis instability and to test the hypothesis that MRI patterns would differ according to time from injury.

METHODS

Over a 5-year period, 164 consecutive patients who had arthroscopically proven syndesmosis instability requiring fixation were retrospectively studied. Patients with distal fibula fractures were not included. Injuries were classified as acute in 108 patients (< 6 weeks), intermediate in 32 (6-12 weeks) and chronic in 24 patients (> 12 weeks).

RESULTS

Posterior malleolus bone oedema was noted in 65 (60.2%), and posterior malleolus fracture in 17 (15.7%) of acute patients, respectively, which did not significantly differ over time. According to MRI, reported rates of posterior syndesmosis disruption significantly differed over time, observed in 101 (93.5%), 28 (87.5%) and 13 (54.2%) of acute, intermediate and chronic patients, respectively (p < 0.001). Apparent rates of PITFL injury significantly reduced with time (p < 0.001).

CONCLUSIONS

MRI detected a posterior syndesmosis injury in 93.5% of patients acutely but became less reliable with time. The clinical relevance of this study is that posterior malleolus bone oedema may be the only marker of a complete syndesmosis injury and can help clinically identify those injuries which require arthroscopic assessment for instability. If suspicious of a high ankle sprain, we advocate early MRI assessment to help determine stable versus unstable injuries as MRI becomes less reliable after 12 weeks.

LEVEL OF EVIDENCE

III.

Diagnostic Accuracy of Radiologic Methods for Ankle Syndesmosis Injury: A Systematic Review and Meta-Analysis

: Misdiagnosis and inadequate treatment of syndesmosis could result in significant long-term morbidity including pain, instability, and degenerative changes of the ankle joint. The objective of this systematic review and meta-analysis was to determine whether radiologic tests accurately and reliably diagnose ankle syndesmosis injury. Medline, Embase, and Cochrane were searched. The database search resulted in 258 full text articles that we assessed for eligibility, we used eight studies that met all the inclusion criteria. In subgroup meta-analysis, the sensitivity analysis showed significant differences only in the MRI (Magnetic Resonance Imaging), and specificity was not statistically significant. In diagnostic meta-analysis, the pooled sensitivity and specificity were 0.528 and 0.984 for X-rays, 0.669 and 0.87&nbsp;for CT (Computed Tomography), and 0.929 and 0.865 for MRI, all respectively. For sensitivity, MRI showed significantly sensitivity as higher than the other methods, and we detected no significance for specificity. Syndesmosis injuries differed significantly in the accuracy of radiological methods according to the presence of accompanied ankle fractures. In patients with fractures, simple radiography has good specificity, and CT and MRI have high sensitivity and specificity irrespective of fracture; in particular, MRI has similar accuracy to gold standard arthroscopic findings.

Relationship between fracture morphology of lateral malleolus and syndesmotic stability after supination-external rotation type ankle fractures

BACKGROUND

Syndesmotic injury with supination-external rotation (SER)-type ankle fractures are well known for the serious damages to the osseous and soft tissue envelope. However, the Lauge-Hansen classification system does not provide sufficient information related to syndesmotic injury. In this study, we aimed to investigate factors for preoperative detection of syndesmotic injury according to fracture patterns in SER III and IV ankle fractures by using radiography and computed tomography (CT).

METHODS

All operative SER III and IV ankle fractures treated by a single surgeon from 2009 to 2015 were enrolled in a retrospective database. Based on computed tomographic evidence and intra-operative Cotton test, stable and unstable groups of the ankle factures were divided.

RESULTS

A total of 52 patients with SER III, 75 patients with SER IV, and 27 patients with SER IV equivalent ankle fractures were identified, with 106 in the unstable syndesmosis group (68.8%) and 48 patients in the stable syndesmosis group (31.2%). Medial space widening and fragment angle of the fibular posterior cortex were significant predictors. The cutoff values of these factors were 4.4 mm and 32.8 degrees, respectively.

CONCLUSIONS

CT was superior to simple radiography in predicting syndesmotic injury at the preoperative period in SER-type III and IV. Medial space widening and fragment angle of the fibular posterior cortex, as predictive factors, showed significant correlations. In particular, sharper fragment angle of the posterior cortex indicated higher probability of instability that remained after fracture fixation.

Weight-Bearing Radiographic Analysis of the Tibiofibular Syndesmosis

Background: Diagnosis of distal tibiofibular syndesmotic injuries includes assessment of radiographs; however, there exist no agreed on standard diagnostic criteria. Previous studies lack consistency with radiographic evaluation methods. The dynamic nature of the ankle joint supports analyzing anatomical parameters using weight-bearing films to assess for tibiofibular syndesmotic integrity. Methods: Weight-bearing tibiofibular syndesmosis radiographs of 39 male and 40 female patients were retrospectively analyzed by 3 investigators, at different levels of orthopaedic training. Measurements 1 cm above the tibial plafond for the anterior tibiofibular overlap (TFO) and tibiofibular clear space (TCS) were recorded and standardized by the fibular width (FW) at 2 time points. Data were compared to check for agreement between the sets of measurements for each rater and agreement between investigators, and to ascertain underlying gender differences. Results: There was good intraobserver correlation (intraclass correlation coefficient [ICC] > 0.90) among investigators for each parameter. A significant difference in the TFO was noted between genders (P < .05). We establish the following radiographic (anteroposterior view) parameters for an intact syndesmosis: male patients, TCS <4.57 mm or TCS/FW <29% and TFO >9.29 mm or TFO/FW > 57%; female patients, TCS <4.28 mm or TCS/FW <30% and TFO >7.41 mm or TFO/FW >51%. Conclusions: Our study provides a more objective approach by utilizing weight-bearing radiographs and performing all measurements 1 cm above the tibial plafond. Levels of Evidence: Level IV.

Epidemiology of syndesmotic fixations in a pediatric center: A 12-year retrospective review

Syndesmosis injuries need to be accurately diagnosed and managed to avoid chronic pain, early arthritis, and instability. To this end, the present study aimed to analyze the epidemiology of syndesmotic injuries in a pediatric ankle fracture cohort and identify patient and surgery-related characteristics.A retrospective review of all the ankle fractures during a 12-year period at a single pediatric referral center was conducted. Inclusion criteria were: a fractured ankle that underwent a surgical fixation, at least 1 radiograph available for review before fixation, available information regarding surgery, including operative report and fluoroscopic images, and younger than 18 years at the time of surgery. Demographic information, trauma, radiographs, surgical details, clinical examination, follow up, outcomes, and physeal status (skeletally immature, transitional, or mature) were recorded. Finally, patients were divided in 2 groups: with or without syndesmotic fixation. Statistical analysis included descriptive statistics, Mann-Whitney test for nonparametric data to compare continuous parameters, and χ test for categorical parameters.A total of 128 patients were included with a mean age of 14.1 years. There were 80 boys and 48 girls. There were 51 skeletally immature patients, 23 with transitional fractures, and 54 that were skeletally mature. The main finding of this study is that only 11 patients from the mature group underwent syndesmotic fixation. There were no cases of syndesmotic fixation in the skeletally immature and transitional groups.This is the first retrospective study to focus specifically on syndesmotic injuries in a pediatric population who underwent ankle fracture fixation. Only 11 skeletally mature patients underwent syndesmotic fixation out of 128 patients in this cohort. This result raises the question of whether there are accurate diagnostic tools to evaluate syndesmosis in children.

Arthroscopic Grading of Injuries of the Inferior Tibiofibular Syndesmosis

The objective of this study was to describe the technical details of performing a newly developed arthroscopic grading of inferior tibiofibular syndesmosis injuries. Arthroscopy is emerging as the gold standard for evaluating painful, unstable ankles. The inferior tibiofibular syndesmosis contributes substantially to disorders of the ankle. However, no structured grading system exists that would help surgeons evaluate injuries of the syndesmosis. Seventy-eight patients with pain or instability symptoms in the ankle were arthroscopically evaluated for syndesmosis injury. The lesions were graded according to the prospectively developed protocol. More than 61% of the patients had syndesmosis disruptions of various grades affecting the anterior/posterior ligaments or both ligaments. Fourteen patients had anterior ligament disruptions whereas 4 patients had posterior lesions; another 7 patients had both ligaments asymmetrically injured. Eighteen of the 78 patients had symmetric grade 1 lesions, and 5 had grade 2 lesions. More than half of chronic ankle pain cases have syndesmotic lesions. Symmetrical lesions of the anterior and posterior ligaments predominate, followed by isolated anterior ligament disruptions. The proposed grading system for inferior tibiofibular syndesmosis disruptions serves as a guide to systematic documentation of injuries of the syndesmosis.