Comparison of magnetic resonance imaging to physical examination for syndesmotic injury after lateral ankle sprain

A Review of Syndesmosis Injuries and Preferred Treatment in Football Players

PURPOSE OF REVIEW

Syndesmotic injuries are common football injuries. The unique demands of football athletes create large magnitude rotational moments about the ankle, even during low impact maneuvers. This review explores the structure and function of the syndesmosis, assesses recent data in football athletes at the professional and collegiate levels regarding epidemiology, describes available treatment options, and provides example cases from the authors' institution. The review concludes with clinical and surgical pearls for the evaluation and treatment of syndesmotic injury.

RECENT FINDINGS

In general, flexible syndesmotic fixation has demonstrated similar clinical outcome scores as rigid fixation. Flexible fixation has demonstrated benefit over rigid fixation in terms of implant failure, hardware removal, and local irritation. Both flexible and rigid fixation remain viable options for treatment of syndesmotic injuries yet the indications for selecting a construct are often subjective. Certain cases of high-risk football players such as linemen may warrant careful consideration of rigid fixation options despite the clinical advantages of flexible fixation. During fixation, direct visualization techniques with open or arthroscopic assistance for reduction of the syndesmosis remain superior and enable diagnosis of chondral defects. Flexible and rigid syndesmotic fixation techniques are viable for treatment of unstable syndesmotic injuries in athletes. Recent literature favors flexible fixation. However, at-risk football athletes or those with length unstable fibula fractures may benefit from rigid or supplemental flexible fixation as opposed to traditional flexible fixation. We recommend direct visualization of reduction at the syndesmosis during surgical treatment of unstable ankle injuries.

Risk Factors for Chronic Syndesmotic Instability After the First Episode of Acute Ankle Sprain: A Cross-Sectional Study of 356 Cases

BACKGROUND

Chronic syndesmotic instability (CSI) can be associated with severe long-term pain and disability. This study aimed to investigate the risk factors associated with the development of CSI in patients who underwent conservative treatment after the first episode of acute ankle sprain (AAS) that did not result in a satisfactory outcome.

METHODS

We retrospectively analyzed the clinical data of patients who underwent ankle arthroscopy for suspected CSI between January 2020 and September 2023. The patients were divided into the instability and stability groups based on the syndesmotic space width measured under arthroscopy, with 3 mm as the critical value. Demographic, arthroscopic, and imaging information such as the anterior talofibular ligament (ATFL), calcaneofibular ligament, posterior talofibular ligament (PTFL), anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), deltoid ligament (DL), interosseous membrane, height of the syndesmotic fluid, injuries of the talus, calcaneus, tibia, and fibula, effusion of the tibiotalar and talocalcaneal joints, fibular morphology, and fibular incisura features, were recorded. Univariate and multivariate analyses were performed successively to identify the risk factors.

RESULTS

Of the 356 patients, 102 developed CSI after the first episode of AAS. In the multivariate analysis, development of CSI was associated with 5 clinical factors: DL injury (odds ratio [OR] 7.453, 95% CI 3.007-18.471; P < .001), positive bandage-binding test (OR 7.196, 95% CI 2.942-17.599; P < .001), grade 2 to 3 injury of the PITFL (OR 2.727, 95% CI 1.044-7.124; P = .041), positive squeeze test (OR 2.455, 95% CI 1.045-5.770; P = .039), and body mass index (BMI) (OR 1.306, 95% CI 1.121-1.522; P < .001).

CONCLUSION

Five key factors were associated with CSI development in patients who underwent conservative treatment after the first episode of AAS that did not result in a satisfactory outcome: DL injury, positive bandage-binding test, grade 2 to 3 injury of the PITFL, positive squeeze test, and BMI.

The most responsive foot position for non-invasive detection of isolated unstable syndesmotic injuries - a 3D analysis

BACKGROUND

The aim of this study was to identify the most responsive foot position for detection of isolated unstable syndesmotic injury.

METHODS

Fourteen paired human cadaveric lower legs were positioned in a pressure-controlled radiolucent frame and loaded under 700 N. Computed tomography scans were performed in neutral position, 15° internal / external rotation, and 20° dorsal / plantar flexion of the foot before and after cutting all syndesmotic ligaments. For each position, generated 3D models of the intact and injured distal tibiofibular joints were matched and analyzed by calculating three parameters: diastasis, anteroposterior displacement, and shortening of the fibula.

RESULTS

Transection of syndesmotic ligaments resulted in significant posterior translation of the fibula (4.34°, SD 1.63°, p < 0.01) compared to uninjured state for external rotation, significant anterior translation (-2.08°, SD 1.65°, p < 0.01) for internal rotation, and significant posterior translation (1.32°, SD 1.16°, p = 0.01) for dorsiflexion. Furthermore, the syndesmotic injury led to significantly increased clear space (0.46 mm, SD 0.46 mm, p = 0.03) in external rotation of the foot.

CONCLUSION

External rotation of the foot under loading seems to be the most responsive position for detection of isolated syndesmotic instability. Under external rotational stress, anteroposterior instability and increased clear space resulting from a complete isolated unstable syndesmotic lesion were most evident.

[Current diagnostics and treatment of ankle sprains in German]

BACKGROUND

Ankle sprains are one of the most frequent injuries of the musculoskeletal system. The injury pattern determines the treatment and are crucial for the outcome. Nonoperative treatment is commonly recommended for isolated injuries of the lateral ligaments but no standard strategy exists in combined ankle ligament injuries. The goal of this national survey was to achieve an overview about the current diagnostic strategies and common treatment concepts in Germany.

MATERIAL AND METHODS

All members of the German Society for Orthopaedics and Trauma Surgery (DGOU) were invited to participate in an anonymous survey about the diagnostic and therapeutic approach in cases of ankle sprains. The online survey consisted of 20 questions. Besides questions about the speciality and scope of activities the participants were ask to depict their diagnostic and therapeutic strategy.

RESULTS

A total of 806 participants completed the survey. Most of them were orthopedic trauma surgeons and worked in a hospital. During the first presentation the anterior drawer test (89.5%) and the inversion/eversion test (81.6%) were most commonly used, 88.1% always make an X‑ray examination and 26.5% an ultrasonography examination. Isolated injuries of the anterior fibulotalar ligament (LFTA) were treated nonoperatively by 99.7% of the participants, 78.8% recommend full weight bearing in an orthesis, 78.8% treat the complete rupture of the lateral ligaments without operation whereas 30.1% stated that they would treat a combined lateral ligaments rupture with an injury of the syndesmosis nonoperatively.

DISCUSSION

Due to the heterogeneity of injury patterns after ankle sprain no consistent recommendations for diagnostics and treatment exist. The Ottawa ankle rules and ultrasonography were not often utilized despite of the good evidence. The isolated rupture of the LFTA is diagnosed and treated according to the national guidelines by most of the participants. In cases of combined injuries of the lateral and medial ankle ligaments the majority choose a nonoperative treatment strategy which is justified by the guidelines with a low level of evidence. Combined injuries of the syndesmosis and the lateral ankle ligaments were treated operatively, which also correlates with the recommendations in the literature. The standard care of ankle sprain in Germany is in accordance with the recommendations from the current literature.

Functional Syndesmotic Widening: A Case Report and Literature Review

Injury to the distal tibiofibular syndesmosis can be a diagnostic challenge in the absence of advanced imaging. We report a case of a 21-year-old male patient who sustained an ankle injury and demonstrated radiological evidence of syndesmosis widening on plain radiographs. He underwent endobutton fixation which resulted in anterior subluxation of the talus and difficulty in ankle dorsiflexion. This is the first case report in the literature of a functional syndesmotic widening and the subsequent sequelae when subjected to a stabilisation procedure. The previously reported risk factors were inconsistent with our patient's demographics of a young, previously obese adult. We postulate that his childhood morbid obesity likely contributed to the functional widening of his ankle syndesmosis.

Ultrasound Assessment of Ankle Syndesmotic Injuries in a Pediatric Population

OBJECTIVE

To determine sensitivity and specificity for anterior-inferior tibiofibular ligament (AiTFL) integrity and tibiofibular clear-space (TFCS) cut-off points for dynamic evaluation using ultrasound (US) in a pediatric population.

DESIGN

Prospective cohort study.

SETTING

Tertiary care university-affiliated pediatric hospital patients between the ages of 12 and 18 sustaining acute ankle trauma with syndesmotic injury.

INTERVENTIONS

Participants were assigned to the syndesmotic injury protocol that included a standardized MRI and US.

MAIN OUTCOME MEASURES

Anterior-inferior tibiofibular ligament integrity for static assessment and TFCS measurements for dynamic assessment on US. For dynamic assessment, the distance between the distal tibia and fibula was first measured in neutral position and then in external rotation for each ankle. The US results on AiTFL integrity were compared with MRI, considered as our gold standard. Optimal cut-off points of TFCS values were determined with receiver operating characteristics curve analysis.

RESULTS

Twenty-six participants were included. Mean age was 14.8 years (SD = 1.3 years). Sensitivity and specificity for AiTFL integrity were 79% and 100%, respectively (4 false negatives on partial tears). For dynamic assessment, the cut-off points for the differences in tibiofibular distance between the 2 ankles in 1) neutral position (TFCS N I-U ) and 2) external rotation (TFCS ER I-U ) were 0.2 mm (sensitivity = 83% and specificity = 80%) and 0.1 mm (sensitivity = 83% and specificity = 80%), respectively.

CONCLUSIONS

Static US could be used in a triage context as a diagnostic tool for AiTFL integrity in a pediatric population as it shows good sensitivity and excellent specificity.

Application of external torque enhances the detection of subtle syndesmotic ankle instability in a weight-bearing CT

PURPOSE

Acute syndesmotic ankle injuries continue to impose a diagnostic dilemma and it remains unclear whether weightbearing and/or external rotation should be added during the imaging process. Therefore, the aim of this study was to assess if combined weightbearing and external rotation increases the diagnostic sensitivity of syndesmotic ankle instability using weightbearing CT (WBCT) imaging, compared to isolated weightbearing.

METHODS

In this retrospective study, patients with an acute syndesmotic ankle injury were analysed using a WBCT (N = 21; Age = 31.6 ± 14.1 years old). Inclusion criteria were an MRI confirmed syndesmotic ligament injury imaged by a WBCT of the ankle during weightbearing and combined weightbearing-external rotation. Exclusion criteria consisted of fracture associated syndesmotic injuries. Three-dimensional (3D) models were generated from the CT slices. Tibiofibular displacement and talar rotation were quantified using automated 3D measurements (anterior tibiofibular distance (ATFD), Alpha angle, posterior Tibiofibular distance (PTFD) and Talar rotation (TR) angle in comparison to the contralateral non-injured ankle.

RESULTS

The difference in neutral-stressed Alpha angle and ATFD showed a significant difference between patients with a syndesmotic ankle lesion and contralateral control (P = 0.046 and P = 0.039, respectively). The difference in neutral-stressed PTFD and TR angle did not show a significant difference between patients with a syndesmotic ankle lesion and healthy ankles (n.s.).

CONCLUSION

Application of combined weightbearing-external rotation reveals an increased ATFD in patients with syndesmotic ligament injuries. This study provides the first insights based on 3D measurements to support the potential relevance of applying external rotation during WBCT imaging. In clinical practice, this could enhance the current diagnostic accuracy of subtle syndesmotic instability in a non-invasive manner. However, to what extent certain displacement patterns require operative treatment strategies has yet to be determined in future studies.

LEVEL OF EVIDENCE

Level III.

The Role of Ultrasound in the Management of Ankle Sprains and a Clinically Relevant Geisinger Ankle Sprain Sports Ultrasound Protocol

ABSTRACT

Ankle sprains are the most common lower extremity injury in physically active individuals. These injuries are classified as lateral, medial, and/or syndesmotic. Treatment may include functional rehabilitation, bracing, weight-bearing restriction, medications, injections, and surgery. While most sprains heal rapidly, permanent disability and pain may arise. Diagnostic ultrasound has been demonstrated to be accurate in diagnosing ligamentous injuries, but it is often excluded from management algorithms that rely on physical examination alone to diagnose significant injuries. This article proposes a comprehensive, evidence-based diagnostic ankle ultrasound protocol to implement in conjunction with thorough history and physical examination. We also review the current literature to describe where this protocol most improves diagnostic accuracy compared with physical examination alone.

Implementing automated 3D measurements to quantify reference values and side-to-side differences in the ankle syndesmosis

Detection of syndesmotic ankle instability remains challenging in clinical practice due to the limitations of two-dimensional (2D) measurements. The transition to automated three-dimensional (3D) measurement techniques is on the verge of a breakthrough but normative and side-to-side comparative data are missing. Therefore, our study aim was two-fold: (1) to establish 3D anatomical reference values of the ankle syndesmosis based on automated measurements and (2) to determine to what extent the ankle syndesmosis is symmetric across all 3D measurements. Patients without syndesmotic pathology with a non-weight-bearing CT scan (NWBCT; N = 38; Age = 51.6 ± 17.43 years) and weight-bearing CT scan (WBCT; N = 43; Age = 48.9 ± 14.3 years) were retrospectively included. After training and validation of a neural network to automate the segmentation of 3D ankle models, an iterative closest point registration was performed to superimpose the left on the right ankle. Subsequently, 3D measurements were manually and automatically computed using a custom-made algorithm and side-to-side comparison of these landmarks allowed one to investigate symmetry. Intra-observer analysis showed excellent agreements for all manual measurements (ICC range 0.85-0.99) and good (i.e. < 2.7° for the angles and < 0.5 mm for the distances) accuracy was found between the automated and manual measurements. A mean Dice coefficient of 0.99 was found for the automated segmentation framework. The established mean, standard deviation and range were provided for each 3D measurement. From these data, reference values were derived to differ physiological from pathological syndesmotic alignment. Furthermore, side-to-side symmetry was revealed when comparing left to right measurements (P > 0.05). In clinical practice, our novel algorithm could surmount the current limitations of manual 2D measurements and distinguish patients with a syndesmotic ankle lesion from normal variance.

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.

Physical Examination of Ankle Sprain and Ankle Instability: Can We Really Divide It into Low and High Ankle Sprains?

Lateral ankle ligament sprains and syndesmotic injuries are two different entities. However, they may be combined under the same spectrum depending on the arch of violence during the injury. Currently, the clinical examination has a limited value in the differential diagnosis between an acute anterior talofibular ligament rupture and a syndesmotic high ankle sprain. However, its use is indispensable for raising a high index of suspicion for detecting these injuries. Based on the mechanism of injury, clinical examination plays an essential role in guiding further imaging and early diagnosis of low/high ankle instability.

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.

Shoe-Integrated Sensor System for Diagnosis of the Concomitant Syndesmotic Injury in Chronic Lateral Ankle Instability: A Prospective Double-Blind Diagnostic Test

Chronic lateral ankle instability (CLAI) is commonly secondary to prior lateral ankle ligament injury, and the concomitant latent syndesmosis injury would prolong recovery time and increase the risk of substantial traumatic arthritis. However, differentiating syndesmotic injury from isolated lateral ankle ligament injury in CLAI cases is difficult by conventional physical and radiological examinations. To improve the accuracy of syndesmotic injury diagnosis, a shoe-integrated sensor system (SISS) is proposed. This system measures plantar pressure during walking to detect the presence of syndesmotic injury. The study included 27 participants who had ankle sprains and underwent an examination. Plantar pressure in eight regions of interest was measured for both limbs, and syndesmotic injuries were examined using arthroscopy. The width of the syndesmosis was measured to evaluate its severity. The characteristics of plantar pressure were compared between patients with normal and injured syndesmosis. The results indicated that peak plantar pressure ratios with logistic regression predicted value > 0.51 accurately distinguished concomitant syndesmotic injury during walking, with high sensitivity (80%) and specificity (75%). The post-test probability of having a syndesmotic injury was positively 80% and negatively 25%. These findings demonstrate the effectiveness of cost-effective wearable sensors in objectively diagnosing concomitant syndesmotic injuries in cases of CLAI.

Comparison of the diagnostic value of measurements of transverse syndesmotic interval and 'lambda sign' in distinguishing latent syndesmotic diastasis in chronic lateral ankle instability: a cross-sectional study of 188 cases

INTRODUCTION

Chronic lateral ankle instability (CLAI) could accompany with latent syndesmotic diastasis (LSD), which is difficult to distinguish before surgery. Tibiofibular interval width and extravasation of joint fluid ('lambda sign') on MRI are widely used in the diagnosis of syndesmotic injury, but the reliability of these methods in distinguishing the associated LSD in CLAI was rarely studied. Our objective was to compare the diagnostic value of the measurement of the transverse tibiofibular interval and 'lambda sign' on MRI in distinguishing LSD in CLAI and to investigate the radiological predictor that best matched the intraoperatively measured syndesmotic width.

METHODS

138 CLAI patients undergoing arthroscopy in our institute from March 2017 to June 2020 were enrolled (CLAI group). Anterior space width (ASW) and posterior space width (PSW) at 10 mm layer above tibial articular and fluid height above tibial articular surface (FH) were measured on preoperative MRI. The same parameters were measured on MRI of 50 healthy volunteers as control group. At arthroscopy, syndesmotic width was measured and the patients were divided into arthroscopic widening (AW) and arthroscopic normal (AN) subgroup taking 2 mm as critical value. The CLAI group was compared with the control group to explore the interval changes related to CLAI. The AW and AN subgroups were compared to explore the potential diagnostic indicators and reference values for the LSD.

RESULTS

All parameters showed significant difference between CLAI group and control group (p < 0.05), but only PSW (p = 0.004) showed significant difference between AW and AN subgroups other than FH (p = 0.461). Only PSW was involved in formula of multiple-factor analysis (p = 0.005; OR, 1.819; 95%CI, 1.196-2.767). ROC analysis showed critical value of PSW was 3.8 mm (sensitivity, 66%; specificity, 66%; accuracy, 66.7%), while accuracy of lambda sign was 41.3%.

CONCLUSIONS

Transverse tibiofibular interval measurements were more reliable than the 'lambda sign' in distinguishing associated LSD in CLAI patients. The PSW ≥ 3.8 mm could be a predictor of syndesmotic diastasis.

Acute Ankle Sprains

Understanding the types of ankle sprains is essential in determining the most appropriate treatment and preventing substantial missed time from sports. Commonly known and recognized is an acute lateral ankle sprain, however, a differentiation should also be made to understand high (syndesmotic) ankle sprains as the mechanism of injury and recovery periods differ between these two types.

Reliability and validity of physical examination tests for the assessment of ankle instability

INTRODUCTION

Clinicians rely on certain physical examination tests to diagnose and potentially grade ankle sprains and ankle instability. Diagnostic error and inaccurate prognosis may have important repercussions for clinical decision-making and patient outcomes. Therefore, it is important to recognize the diagnostic value of orthopaedic tests through understanding the reliability and validity of these tests.

OBJECTIVE

To systematically review and report evidence on the reliability and validity of orthopaedic tests for the diagnosis of ankle sprains and instability.

METHODS

PubMed, CINAHL, Scopus, and Cochrane databases were searched from inception to December 2021. In addition, the reference list of included studies, located systematic reviews, and orthopaedic textbooks were searched. All articles reporting reliability or validity of physical examination or orthopaedic tests to diagnose ankle instability or sprains were included. Methodological quality of the reliability and the validity studies was assessed with The Quality Appraisal for Reliability studies checklist and the Quality Assessment of Diagnostic Accuracy Studies-2 respectively. We identified the number of times the orthopaedic test was investigated and the validity and/or reliability of each test.

RESULTS

Overall, sixteen studies were included. Three studies assessed reliability, eight assessed validity, and five evaluated both. Overall, fifteen tests were evaluated, none demonstrated robust reliability and validity scores. The anterolateral talar palpation test reported the highest diagnostic accuracy. Further, the anterior drawer test, the anterolateral talar palpation, the reverse anterior lateral drawer test, and palpation of the anterior talofibular ligament reported the highest sensitivity. The highest specificity was attributed to the anterior drawer test, the anterolateral drawer test, the reverse anterior lateral drawer test, tenderness on palpation of the proximal fibular, and the squeeze test.

CONCLUSION

Overall, the diagnostic accuracy, reliability, and validity of physical examination tests for the assessment of ankle instability were limited. Physical examination tests should not be used in isolation, but rather in combination with the clinical history to diagnose an ankle sprain. Preliminary evidence suggests that the overall validity of physical examination for the ankle may be better if conducted five days after the injury rather than within 48 h of injury.

Bilateral ankle syndesmosis injury: a rare case report

This report describes a case of bilateral acute ankle syndesmosis injuries in a 15-year-old male basketball player. The patient had a background of previous inversion injuries but no symptoms of chronic pain or instability. The case report illustrates the importance of clinical suspicion when evaluating acute syndesmosis injuries in conjunction with radiographic assessments in primary care. This is the first reported case of such injury in bilateral limbs.

Anatomically Fixed Posterior Malleolar Fractures in Syndesmosis Injuries without Transsyndesmotic Screw Fixation

BACKGROUND

The stability of the syndesmosis is extremely important in terms of syndesmosis injury, ankle instability, and posttraumatic osteoarthritis development following ankle fractures. The aim of this study is to evaluate 1-year radiographic outcomes after posterior malleolar fixation in lateral and posterior malleolar fractures and trimalleolar fractures without transsyndesmotic screw fixation.

METHODS

Ninety-four patients who underwent posterior malleolar fixation with posterolateral approach between January 2017 and June 2019 were evaluated retrospectively. The patients were evaluated with parameters such as demographic characteristics, fracture type, injury mechanism, physical examination, and radiographic measurements. The stability of the syndesmosis was evaluated by an intraoperative Cotton test and by measuring the tibiofibular overlap, tibiofibular clear space, and medial clear space parameters preoperatively on the immediate postoperative, first-year weightbearing ankle anteroposterior radiographs.

RESULTS

In immediate postoperative measurements on radiographs, although the mean tibiofibular overlap (P < .001) increased, the mean tibiofibular clear space (P < .001) and mean medial clear space (P < .001) decreased compared with preoperative radiographs. Immediate postoperative mean tibiofibular overlap, tibiofibular clear space, and medial clear space compared with postoperative first-year mean tibiofibular overlap (P = .39), tibiofibular clear space (P = .23), and medial clear space (P = .43) were not statistically significant. Bone union was completed radiographically at a median of 3.4 ± 1.8 months after surgery.

CONCLUSION

After posterior malleolar fractures, anatomic reduction of the posterior malleolus and posterior inferior tibiofibular ligament complex provides strong syndesmosis stability as measured radiographically at 1 year. Patients may not need additional transsyndesmotic screw fixation.

LEVEL OF EVIDENCE

Level IV, case series.

Short-Term Effect of Manual Therapy &amp; Taping on Subacute Ankle Sprains with Potential Syndesmotic Sprain: A Case Series

STUDY DESIGN

Case Series.

BACKGROUND

Syndesmotic ankle sprains can occur in up to 17% of ankle trauma and can lead to long-term disability. This study describes the management of seven patients with subacute, high-grade ankle sprains with concerns of concurrent syndesmotic strain utilizing manual therapy and rigid sports taping.

METHODS

Seven active duty military members with clinically diagnosed, high-grade ankle sprains and concern for syndesmotic sprain participated in this case series. All patients received multi-modal treatment consisting of manual therapy, rigid sports taping, progressive exercises, and proprioceptive training. Decrease in Numeric Pain Rating Scale (NPRS) following manual therapy and taping treatment, number of sessions before discharge, and the Global Rating of Change (GROC) at discharge were retrospectively reviewed.

RESULTS

All patients demonstrated an immediate decrease in NPRS following treatment on average of 5 points (range, 3-8 points) with a functional asterisk sign. The improvement in pain and function was maintained until the next treatment session with a mean GROC score of +3. The mean time until recovery was 5.4 weeks (range, 1-8 weeks).

DISCUSSION

A multimodal approach for patients diagnosed clinically with high-grade ankle sprains and concern for syndesmotic sprain was useful to immediately reduce pain and improve function, and improvements were maintained throughout the duration of care. This study is the first to assess a combination of manual therapy and rigid sports taping for the treatment of suspected syndesmotic ankle sprains, and more stringent research is needed to validate the findings.

LEVEL OF EVIDENCE

Therapy, 4.

Comparison between cotton test and tap test for the assessment of coronal syndesmotic instability: A cadaveric study

INTRODUCTION

In surgically treated rotational malleolar fractures, residual syndesmotic instability is typically assessed following fixation with the widely used intraoperative Cotton test. However, due to its dynamic nature, there are inconsistencies of the magnitude and direction of the distraction force when attempting to pull the fibula away from the tibia using a bone hook. The novel Tap test advances a cortical tap through a drilled hole in the fibula with a stable, unidirectional distraction force applied to the tibia. The objective of this cadaveric study was to compare the Cotton and Tap tests as diagnostic tools for coronal plane syndesmotic instability.

METHODS

Tibiofibular Clear Space (TFCS) of 10 cadaveric specimens was measured for: intact, non-stressed; intact, stressed; injured, non-stressed; and injured, stressed (Tap and Cotton tests). In injured conditions, the syndesmotic ligamentous complex was sectioned using an anterolateral longitudinal approach. Perfect fluoroscopic Mortise images were acquired for all conditions. Two independent and blinded Orthopaedic Foot and Ankle Surgeons measured TFCS 1 cm proximal to the ankle joint line. Intra and interobserver reliabilities were assessed by Intraclass Correlation Coefficient. Syndesmotic TFCS values for all conditions were compared by paired Wilcoxon. Diagnostic performance of the Cotton and Tap tests was assessed using a relative increase of TFCS > 2 mm when comparing intact stressed and injured stressed conditions. P-values <0.05 were considered significant.

RESULTS

The intraclass correlation coefficient for intraobserver and interobserver reliability was respectively 0.96 and 0.79. TFCS measurements were similar in intact non-stressed, intact stressed (both Cotton and Tap tests) and injured non-stressed conditions, with mean values and 95% Confidence Intervals of: intact non-stressed, 3.5 mm; intact stressed, 3.6 mm (Cotton test) and 4.0 mm (Tap test); injured non-stressed, 3.8 mm. The Cotton test and Tap test had, respectively, 73.3% and 70% sensitivity, 100% and 90% specificity, 86.7% and 80% diagnostic accuracy.

CONCLUSIONS

Our cadaveric study compared the Cotton and Tap tests for detection of coronal plane syndesmotic instability. Both tests demonstrated similar increases in the TFCS measurements in stressed injured conditions when compared to intact non-stressed and stressed conditions, as well as injured non-stressed conditions.

Ankle and syndesmosis instability: consensus and controversies

Ankle sprains are mainly benign lesions, but if not well addressed can evolve into permanent disability. A non-treated lateral, syndesmotic or medial ankle instability can evolve into ankle osteoarthritis. For this reason, diagnosis and treatment of these entities is of extreme importance.In general, acute instabilities undergo conservative treatment, while chronic instabilities are better addressed with surgical treatment. It is important to identify which acute instabilities are better treated with early surgical treatment.Syndesmosis injuries are frequently overlooked and represent a cause for persistent pain in ankle sprains. Unstable syndesmotic lesions are always managed by surgery.Non-treated deltoid ligament ruptures can evolve into a progressive valgus deformity of the hindfoot, due to its links with the spring ligament complex. This concept would give new importance to the diagnosis and treatment of acute medial ligament lesions.Multi-ligament lesions are usually unstable and are better treated with early surgery. A high suspicion rate is required, especially for combined syndesmotic and medial lesions or lateral and medial lesions.Ankle arthroscopy is a powerful tool for both diagnostic and treatment purposes. It is becoming mandatory in the management of ankle instabilities and multiple arthroscopic lateral/syndesmotic/medial repair techniques are emerging. Cite this article: EFORT Open Rev 2021;6:420-431. DOI: 10.1302/2058-5241.6.210017.

APKASS Consensus Statement on Chronic Syndesmosis Injury, Part 1: Clinical Manifestation, Radiologic Examination, Diagnosis Criteria, Classification, and Nonoperative Treatment

Background

Clinical manifestation, radiologic examination, diagnostic criteria, classification, and nonoperative treatment strategies regarding chronic syndesmosis injury remain unclear.

Purpose

An international group of experts representing the fields of sports injuries in the foot and ankle area were invited to collaboratively advance toward consensus opinions based on the best available evidence regarding chronic syndesmosis injuries. All were members of the Asia-Pacific Knee, Arthroscopy and Sports Medicine Society (APKASS).

Study Design

Consensus statement.

Methods

From November to December 2020, a total of 111 international experts on sports medicine or ankle surgery participated in a 2-stage Delphi process that included an anonymous online survey and an online meeting. A total of 13 items with 38 statements were drafted by 13 core authors. Of these, 4 items with 15 clinical questions and statements were related to the clinical manifestation, radiologic examination, diagnostic criteria, classification, and nonoperative treatment strategies for chronic syndesmosis injury and are presented here. Each statement was individually presented and discussed, followed by a general vote. The strength of consensus was characterized as follows: consensus, 51% to 74%; strong consensus, 75% to 99%; unanimous, 100%.

Results

Of the 15 questions and statements, 5 reached unanimous support and 10 achieved strong consensus.

Conclusion

This APKASS consensus statement, developed by international experts in the field, will assist surgeons and physical therapists with diagnosis, classification, and nonoperative treatment strategies for chronic syndesmosis injury.

Diagnosing instability of ligamentous syndesmotic injuries: A biomechanical perspective

BACKGROUND

High ankle sprains are insidious injuries associated with a long recovery period, functional impairment and long-term sequelae if mistreated. This systematic review investigates the biomechanical knowledge on the kinematic consequences of sequential syndesmotic ligamentous injuries, aiming to furnish an updated and objective contribution for the critical appraisal and further elaboration of current diagnostic algorithms for high ankle sprains.

METHODS

A systematic review was performed to identify human biomechanical studies evaluating the stabilizing role of the syndesmotic ligaments. Special attention was paid to identify the smallest lesion within the progressive simulated injuries able to provoke statistically significant changes of the syndesmotic kinematic on the specimen, the mechanical solicitation that provoked it, and the measurement methodology.

FINDINGS

Fourteen studies were included. In eight articles already an isolated injury to the anterior inferior tibiofibular ligament provoked significant changes of the syndesmotic kinematic, which was always depicted under an external rotation torque. In three articles an isolated deltoid ligament injury provoked significant changes of the syndesmotic kinematic. Four articles described a direct measure of the bony movements, whereas seven collected data through conventional radiography or CT-scan imaging and three via a 3D motion analysis tracking system.

INTERPRETATION

An isolated lesion of the anterior inferior tibiofibular ligament can provoke significant kinematic modifications in ex vivo syndesmotic models and may be responsible of subtle patterns of dynamic instability, regardless of further syndesmotic ligamentous injuries. The data observed support efforts to define reliable CT imaging parameters to improve non-invasive diagnostic of subtle forms of syndesmotic instability.

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.

Robust Method for Mid-Activity Tracking and Evaluation of Ankle Health Post-Injury

OBJECTIVE

To present a robust methodology for evaluating ankle health during ambulation using a wearable device. Methods: We developed a novel data capture system that leverages changes within the ankle during ambulation for real-time tracking of bioimpedance. The novel analysis compares the range of reactance at 5 kHz to the range of reactance at 100 kHz; which removes the technique's previous reliance on a known baseline. To aid in interpretation of the measurements, we developed a quantitative simulation model based on a literature review of the effects on joint bioimpedance of variations in edematous fluid volume, muscle fiber tears, and blood flow changes. Results: The results of the simulation predicted a significant difference in the ratio of the range of the reactance from 5 kHz to 100 kHz between the healthy and injured ankles. These results were validated in 15 subjects - with 11 healthy ankles and 7 injured ankles measured. The injured subjects had lateral ankle sprains 2-4 weeks prior to the measurement. The analysis technique differentiated between the healthy and the injured population (p<<0.01), and a correlation (R = 0.8) with a static protocol previously validated for its sensitivity to edema. Conclusion: The technology presented can detect variations in ankle edema and structural integrity of ankles, and thus could provide valuable feedback to clinicians and patients during the rehabilitation of an ankle injury. Significance: This technology could lead to better-informed decision making regarding a patient's readiness to return to activity and / or tailoring rehabilitation activities to an individual's changing needs.

Traumatic injuries of the distal tibiofibular syndesmosis

The distal tibiofibular syndesmosis (DTFS) is frequently injured during ankle trauma. The sequelae can be significant, including chronic instability, early osteoarthritis and residual pain. The aim of this study is to summarize the current state knowledge about these injuries by answering four questions. They frequently occur in the context of an ankle sprain (20-40% of cases) or during various types of ankle fractures (20-100% of cases). They cannot be ruled out based solely on fracture type and must be investigated when a fibular or posterior malleolar fracture is present. Clinical examination and imaging are essential but do not provide a definitive diagnosis. Ultrasonography, CT scan and MRI have high sensitivity, but their static nature does not allow a treatment strategy to be defined. Dynamic radiographs must be taken, either with load or during a procedure. If instability is detected, stabilization is the general rule. In fracture cases, reduction is achieved by restoring the length and rotation of the distal fibular fragment, preferably during an open procedure. In sprain cases, reduction is not a problem unless there is ligament interposition. Tibiofibular fixation is done 1.5 to 3cm from the talocrural joint, while ensuring the reduction is perfect. The main complication-non-healing of the syndesmosis-is attributed to poor initial reduction. This or functional discomfort during weight bearing will require removal of the fixation hardware. In most cases, this allows functional recovery and correction of the inadequate reduction. Persistence of instability will require ligament reconstruction or fusion of the syndesmosis. Chronic instability can lead to ankle osteoarthritis. LEVEL OF EVIDENCE: V, expert opinion.

Delayed stabilisation of dynamically unstable syndesmotic injuries results in worse functional outcomes

PURPOSE

Patients with primarily ligamentous injuries of the distal tibiofibular joint comprise up to 12% of all ankle sprains. Patients frequently present late after a syndesmosis injury and delayed treatment potentially leads to pain, prolonged disability and arthritis in the long term. This study aimed to assess clinical outcomes in patients who required syndesmosis fixation in the presence of arthroscopically proven instability, the hypothesis being that a delay to treatment would be associated with worse function.

METHOD

A retrospective cohort study was performed of patients with dynamic instability requiring fixation between the years of 2010-2016. The procedures were performed by two foot and ankle fellowship trained orthopaedic surgeons, over three hospital sites. Patients were classified into three groups based on the time since injury to surgery, acute syndesmotic injury (< 6 weeks), sub-acute (6 weeks-6 months) and chronic syndesmotic injury (> 6 months). Functional scores were retrospectively collected using the Foot and Ankle Outcome Score (FAOS).

RESULTS

Compared to patients with acute injuries, those with chronic injuries had significantly lower FAOS subscales (p < 0.001), with the greatest difference in quality of life (- 20.7, 95% CI - 31.6 to - 9.8, p = 0.012). There was a mean follow-up of 4.3 years. Although the average FAOS subscales in those with sub-acute injuries were lower than in those with acute injuries, the difference was not statistically significant.

CONCLUSION

The results of this study suggest that delayed surgical stabilisation (> 6 months) is associated with significantly worse clinical function, and thus timely identification and early referral of those patients with potentially unstable syndesmotic injuries is recommended.

LEVEL OF EVIDENCE

Level III.

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.

Physical Examination of the Ankle: A Review of the Original Orthopedic Special Test Description and Scientific Validity of Common Tests for Ankle Examination

OBJECTIVES

To review the literature, identify and describe commonly used special tests for diagnosing injury to the ligaments of the ankle complex, present the distinguishing characteristics and limitations of each test, and discuss the current evidence for the clinical use of each test.

DATA SOURCES

Multiple PubMed (1920-2018) and CINAHL (1920-2018) searches were conducted and various musculoskeletal examination textbooks were reviewed to examine common orthopedic tests used to assess the ankle. The articles were reviewed for additional references and the search continued until the original description was found when possible.

STUDY SELECTION

All articles discussing the performance of the test or its validity (ie, sensitivity and specificity) were reviewed and summarized.

DATA EXTRACTION

Articles were reviewed for additional references and the search continued until the original description was found when possible.

DATA SYNTHESIS

The literature was reviewed, commonly used special tests for diagnosing ankle injuries were identified and described, distinguishing characteristics and limitations of each test were presented, and the current evidence for the clinical use of each test was discussed.

CONCLUSIONS

A complete physical examination is critical in the diagnosis of ankle injuries. The combination of available information such as mechanism of injury, all signs and symptoms, and changes in gait, is key to a conclusive and correct diagnosis. Clinicians should be aware of the severely limited evidence supporting the use of many commonly used special tests. Applying evidence from the literature will improve diagnostic accuracy. Further research is needed to understand the performance ability of special tests, both individually and when grouped as part of a test battery.

Syndesmosis Injury From Diagnosis to Repair: Physical Examination, Diagnosis, and Arthroscopic-assisted Reduction

Injuries to the tibio-fibular syndesmotic ligaments are different than ankle collateral ligament injuries and occur in isolation or combination with malleolar fractures. Syndesmotic ligament injury can lead to prolonged functional limitations and ultimately long-term ankle dysfunction if not identified and treated appropriately. The syndesmosis complex is a relatively simple construct of well-documented ligaments, but the dynamic kinematics and the effects of disruption have been a point of contention in diagnosis and treatment. Syndesmotic ligament injuries are sometimes referred to as "high ankle sprains" because the syndesmotic ligaments are more proximal than the collateral ligaments of the ankle joint. Rotational injuries to the ankle often result in malleolar fractures, which can be combined with ankle joint or syndesmotic ligament injuries. Most of the orthopaedic literature to this point has addressed syndesmosis ligament injuries in combination with fractures and not isolated syndesmotic ligament injuries. Thus, we propose a simplified general video guide to do the diagnostic examinations and arthroscopic-assisted reduction based on current evidence-based medicine.

Cross-cultural adaptation, validity, and reliability of Turkish version of Identification of Functional Ankle Instability (IdFAI) scale

OBJECTIVE

This study aimed to develop the Turkish version of Identification of Functional Ankle Instability (TV_IdFAI) scale and evaluate its validity and reliability.

METHODS

A total of 100 participants (54 men and 46 women; 50 volleyball players and 50 sedentary individuals) between 18 and 38 years of age were included this study. The construct validity, reference validity, sensitivity, specificity, and test-retest reliability of TV_IdFAI were evaluated. For the test-retest reliability, the scale was applied to all participants again in 10-14 days. A correlation between the scale scores and test-retest results was examined with intraclass correlation coefficient. To evaluate the construct validity, a factor analysis method was used. For reference validity, a sports physician evaluated all participants and the clinical diagnoses were compared with total score of the scale. Sensitivity and specificity were calculated to evaluate the classification success of the scale with specified cutoff.

RESULTS

TV_IdFAI scale was grouped under two separate factors. It was determined that the variance for factor 1, factor 2 and for scale was 46.68%, 15.70%, and 62.38%, respectively. There was a statistically significant relationship 0.74 (95% CI 0.64-0.84; p<0.001) between the physician's diagnosis and TV_IdFAI in terms of reference validity. The sensitivity and specificity of TV_IdFAI was 0.61 and 0.80, respectively. The reliability of TV_IdFAI was 0.94 (95% CI 0.92-0.96; p<0.001).

CONCLUSION

This study shows that TV_IdFAI is a simple, easy to apply, reliable, and valid scale to define functional ankle instability in Turkish population.

LEVEL OF EVIDENCE

Level II, Diagnostic study.

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.

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.

Robust Longitudinal Ankle Edema Assessment Using Wearable Bioimpedance Spectroscopy

OBJECTIVE

We present a robust methodology for tracking ankle edema longitudinally based on bioimpedance spectroscopy (BIS).

METHODS

We designed a miniaturized BIS measurement system and employed a novel calibration method that enables accurate, high-resolution measurements with substantially lower power consumption than conventional approaches. Using this state-of-the-art wearable BIS measurement system, we developed a differential measurement technique for robust assessment of ankle edema. This technique addresses many of the major challenges in longitudinal BIS-based edema assessment, including day-to-day variability in electrode placement, positional/postural variability, and intersubject variability.

RESULTS

We first evaluated the hardware in bench-top testing, and determined the error of the bioimpedance measurements to be 0.4 Ω for the real components and 0.54 Ω for the imaginary components with a resolution of 0.2 Ω. We then validated the hardware and differential measurement technique in: 1) an ex vivo, fresh-frozen, cadaveric limb model, and 2) a cohort of 11 human subjects for proof of concept (eight healthy controls and five subjects with recently acquired acute unilateral ankle injury).

CONCLUSION

The hardware design, with novel calibration methodology, and differential measurement technique can potentially enable long-term quantification of ankle edema throughout the course of rehabilitation following acute ankle injuries.

SIGNIFICANCE

This could lead to better-informed decision making regarding readiness to return to activities and/or tailoring of rehabilitation activities to an individual's changing needs.

MANAGEMENT OF ACUTE GRADE II LATERAL ANKLE SPRAINS WITH AN EMPHASIS ON LIGAMENT PROTECTION: A DESCRIPTIVE CASE SERIES

Background and Purpose

Lateral ankle sprain the most common injury in physically active populations. Individuals who sustain an acute lateral ankle sprain may not receive timely formal rehabilitation and are at an increased risk to have subsequent sprains which can lead to chronic pain and instability. Attention to essential factors for ligament protection and healing while preserving ankle movement, may result in a more stable yet mobile ankle offering improved outcomes. The purpose of this case series was to describe the methods and observe the outcomes associated with a comprehensive strategy for managing acute first episode grade II lateral ankle sprains.

Study design

Prospective case series.

Case Descriptions and Interventions

Ten patients (mean age 26.7 years, range 16-51 years, mean 2.3 days from injury) with acute grade II lateral ankle sprain were treated with an approach to protect the injured ligament, prevent impairments to movement, restore strength and proprioception, and progress to full function. Patient outcomes were assessed at four, eight and 12 weeks. Follow-up interviews at six and 12 months assessed injury recurrence.

Outcomes

Patients were treated for an average of eight sessions over a mean of seven weeks. Rapid change in self-reported function, ankle ROM, and pain were observed in the first four weeks of care. Clinically meaningful improvements in function and ankle ROM were also noted at eight weeks and maintained at 12-week follow-ups. All patients returned to desired physical activity with only a single re-sprain event within one year after injury.

Conclusion

The results of this prospective case series suggest that a treatment approach designed to protect the injured ligament, maintain and restore normal ankle motion, and provide a tailored functional pathway to return to run and sport demonstrated resolution of symptoms and improvement in reported functional outcomes in a group of patients following grade II acute primary ankle sprain.

Level of Evidence

Level IV, Case Series.

MRI of ankle sprain: the association between joint effusion and structural injury severity in a large cohort of athletes

OBJECTIVE

To test the hypothesis if presence and amount of effusion in the tibiotalar and talocalcaneal joints are associated with an increased risk for severe structural injury in ankle sprains.

METHODS

A total of 261 athletes sustaining acute ankle sprains were assessed on MRI for the presence and the amount of joint effusion in the tibiotalar and talocalcaneal joints, as well as for ligamentous and osteochondral injury. Specific patterns of injury severity were defined based on lateral collateral ligament, syndesmotic, and talar osteochondral involvement. The presence and the amount effusion (grades 1 and 2) were considered as risk factors for severe injury, while physiological amount of fluid (grade 0) was considered as the referent. Conditional logistic regression was used to assess the risk for associated severe injuries (syndesmotic ligament rupture and talar osteochondral lesions) based on the presence and amount of tibiotalar and talocalcaneal effusions.

RESULTS

For ankles exhibiting large (grade 2) effusion in the tibiotalar joint (without concomitant grade 2 effusion in the talocalcaneal joint), the risk for partial or complete syndesmotic ligament rupture was increased more than eightfold (adjusted odds ratio 8.7 (95% confidence intervals 3.7-20.7); p < 0.001). The presence of any degree of effusion in any of the joints was associated with an increased risk for severe talar osteochondral involvement (several odds ratio values reported; p < 0.001), including large subchondral contusions and any acute osteochondral lesion.

CONCLUSION

The presence of tibiotalar and talocalcaneal effusions is associated with an increased risk for severe concomitant structural injury in acute ankle sprains.

KEY POINTS

• For ankles exhibiting severe (grade 2) effusion in the tibiotalar joint after sprain, the risk for partial or complete syndesmotic ligament rupture increases more than eightfold. • The presence of effusion in both tibiotalar and talocalcaneal joints is associated with an increased risk for severe ligament injury such as complete ATFL rupture as well as partial or complete syndesmotic ligament rupture. • The presence of effusion in the tibiotalar or talocalcaneal joints after sprain is associated with an increased risk for severe talar osteochondral involvement.

Management of foot and ankle injuries in pediatric and adolescent athletes: a narrative review

In this review, we focus on the treatment of injuries to the foot and ankle in the adolescent athlete. While many injuries in the adolescent foot and ankle are similar to or overlap with their counterparts in the adult population, the anatomy of the adolescent ankle, especially the presence of growth plates, results in different injury patterns in many cases and calls for specific management approaches. We discuss the unique anatomy of the pediatric patient as well as the diagnostic evaluation and treatment of common injuries in the young athlete.

Intraoperative tap test for coronal syndesmotic instability: A cadaveric study

INTRODUCTION

Precise diagnosis of distal tibiofibular syndesmotic injury is challenging, and a gold standard diagnostic test has still not been established. Tibiofibular clear space identified on radiographic imaging is considered the most reliable indicator of the injury. The Cotton test is the most widely used intraoperative technique to evaluate the syndesmotic integrity although it has its limitations. We advocate for a novel intra operative test using a 3.5 mm blunt cortical tap.

METHODS

Tibiofibular clear space was assessed in nine cadaveric specimens using three sequential fluoroscopic images. The first image was taken prior to the application of the tap test (intact, non-stressed). Then, a 2.5 mm hole was drilled distally on the lateral fibula, and a 3.5 mm cortical tap was then threaded in the hole. The tap test involved gradually advancing the blunt tip against the lateral tibia, providing a tibiofibular separation force (intact, stressed). This same stress was then applied after all syndesmotic ligaments were released (injured, stressed). Measurements were compared by one-way ANOVA and paired Student's t-test. Intra and inter-observer agreements were evaluated by intraclass correlation coefficient (ICC). P-values <.05 were considered significant.

RESULTS

We found excellent intra-observer (0.97) and inter-observer (0.98) agreement following the imaging assessment. Significant differences were found in the paired comparison between the groups (p < .05). When using an absolute value for TFCS >6 mm as diagnostic for coronal syndesmotic instability, the tap test demonstrated a 96.3% sensitivity and specificity, a 96.3% PPV and NPV and a 96.3% accuracy in diagnosing coronal syndesmotic instability.

CONCLUSIONS

Our cadaveric study demonstrated that this novel coronal syndesmotic instability test using a 3.5 mm blunt cortical tap is a simple, accurate and reliable technique able to demonstrate significant differences in the tibiofibular clear space when injury was present. It could represent a more controlled and stable alternative to the most used Cotton test.

Syndesmotic stability: Is there a radiological normal?-A systematic review

BACKGROUND

Syndesmotic injury and instability poses a diagnostic challenge with unreliable clinical tests and inconsistent radiologic measures. Thus, used widely in clinical practice, there is huge debate pertaining to the reliability and validity of the radiologic parameters used for syndesmotic instability.

OBJECTIVE

Hence the purpose of the review was to explore the normal radiologic measures and morphometrics of distal tibiofibular syndesmosis and its relationships, which can aid in diagnosing syndesmotic instability.

METHOD

Computerised literature searches was performed for articles published in English using Pubmed, from inception through June 2016. All published articles reporting the normal anatomic and morphometric measures of distal tibiofibular syndesmosis with the use of any radiological modality individually or in combination, either in cadaveric or in live subjects were included. Studies done on or reporting of measures in healthy ankles or radiologically normal ankles were only included.

RESULTS

In this review wide anatomic and morphologic variability was observed amidst the landmarks used commonly for assessing syndesmotic instability and hence the normal measures. Further age and gender based variations were seen across the most commonly used radiologic measures for syndesmotic instability diagnosis, demanding the modification of existing radiologic criteria.

Management of acute injuries of the tibiofibular syndesmosis

The syndesmosis is important for ankle stability and load transmission and is commonly injured in association with ankle sprains and fractures. Syndesmotic disruption is associated with between 5 and 10% of ankle sprains and 11-20% of operative ankle fractures. Failure to recognize and appropriately treat syndesmotic disruption can portend poor functional outcomes for patients; therefore, early recognition and appropriate treatment are critical. Syndesmotic injuries are difficult to diagnose, and even when identified and treated, a slightly malreduced syndesmosis can lead to joint destruction and poor functional outcomes. This review will discuss the relevant anatomy, biomechanics, mechanism of injury, clinical evaluation, and treatment of acute injuries to the ankle syndesmosis.

Biomechanical Analysis of the Individual Ligament Contributions to Syndesmotic Stability

BACKGROUND

Biomechanical data and contributions to ankle joint stability have been previously reported for the individual distal tibiofibular ligaments. These results have not yet been validated based on recent anatomic descriptions or using current biomechanical testing devices.

METHODS

Eight matched-pair, lower leg specimens were tested using a dynamic, biaxial testing machine. The proximal tibiofibular joint and the medial and lateral ankle ligaments were left intact. After fixation, specimens were preconditioned and then biomechanically tested following sequential cutting of the tibiofibular ligaments to assess the individual ligamentous contributions to syndesmotic stability. Matched paired specimens were randomly divided into 1 of 2 cutting sequences: (1) anterior-to-posterior: intact, anterior inferior tibiofibular ligament (AITFL), interosseous tibiofibular ligament (ITFL), deep posterior inferior tibiofibular ligament (PITFL), superficial PITFL, and complete interosseous membrane; (2) posterior-to-anterior: intact, superficial PITFL, deep PITFL, ITFL, AITFL, and complete interosseous membrane. While under a 750-N axial compressive load, the foot was rotated to 15 degrees of external rotation and 10 degrees of internal rotation for each sectioned state. Torque (Nm), rotational position (degrees), and 3-dimensional data were recorded continuously throughout testing.

RESULTS

Testing of the intact ankle syndesmosis under simulated physiologic conditions revealed 4.3 degrees of fibular rotation in the axial plane and 3.3 mm of fibular translation in the sagittal plane. Significant increases in fibular sagittal translation and axial rotation were observed after syndesmotic injury, particularly after sectioning of the AITFL and superficial PITFL. Sequential sectioning of the syndesmotic ligaments resulted in significant reductions in resistance to both internal and external rotation. Isolated injuries to the AITFL resulted in the most substantial reduction of resistance to external rotation (average of 24%). However, resistance to internal rotation was not significantly diminished until the majority of the syndesmotic structures had been sectioned.

CONCLUSION

The ligaments of the syndesmosis provide significant contributions to rotary stability of the distal tibiofibular joint within the physiologic range of motion.

CLINICAL RELEVANCE

This study defined normal motion of the syndesmosis and the biomechanical consequences of injury. The degree of instability was increased with each additional injured structure; however, isolated injuries to the AITFL alone may lead to significant external rotary instability.

Magnetic resonance imaging characterization of individual ankle syndesmosis structures in asymptomatic and surgically treated cohorts

PURPOSE

Historically, syndesmosis injuries have been underdiagnosed. The purpose of this study was to characterize the 3.0-T MRI presentations of the distal tibiofibular syndesmosis and its individual structures in both asymptomatic and injured cohorts.

METHODS

Ten age-matched asymptomatic volunteers were imaged to characterize the asymptomatic syndesmotic anatomy. A series of 21 consecutive patients with a pre-operative 3.0-T ankle MRI and subsequent arthroscopic evaluation for suspected syndesmotic injury were reviewed and analysed. Prospectively collected pre-operative MRI findings were correlated with arthroscopy to assess diagnostic accuracy [sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV)].

RESULTS

Pathology diagnosed on pre-operative MRI correlated strongly with arthroscopic findings. Syndesmotic ligament disruption was prospectively diagnosed on MRI with excellent sensitivity, specificity, PPV, NPV, and accuracy: anterior inferior tibiofibular ligament (87.5, 100, 100, 71.4, 90.5 %); posterior inferior tibiofibular ligament (N/A, 95.2, 0.0, 100, 95.2 %); and interosseous tibiofibular ligament (66.7, 86.7, 66.7, 86.7, 81.0 %).

CONCLUSIONS

Pre-operative 3.0-T MRI demonstrated excellent accuracy in the diagnosis of syndesmotic ligament tears and allowed for the visualization of relevant individual syndesmosis structures. Using a standard clinical ankle MRI protocol at 3.0-T, associated ligament injuries could be readily identified. Clinical implementation of optimal high-field MRI sequences in a standard clinical ankle MRI exam can aid in the diagnosis of syndesmotic injuries, augment pre-operative planning, and facilitate anatomic repair by providing additional details regarding the integrity of individual syndesmotic structures not discernible through physical examination and radiographic assessments.

LEVEL OF EVIDENCE

II.

Classification and diagnosis of acute isolated syndesmotic injuries: ESSKA-AFAS consensus and guidelines

PURPOSE

The aim of the present study was to perform a systematic review of the current classification systems, and the clinical and radiological tests for the acute isolated syndesmotic injuries to identify the best method of classification and diagnosis allowing the surgeon to choose the appropriate management.

METHODS

A systematic review of the literature according to the PRISMA guidelines has been performed. A comprehensive search using various combinations of the keywords "classification", "grading system", "ankle injury", "ligament", "syndesmotic injury", "internal fixation", "acute", "synostosis", "ligamentoplasties", "clinical", "radiological" over the years 1962-2015 was performed. The following databases were searched: MEDLINE, Google Scholar, EMBASE and Ovid.

RESULTS

The literature search resulted in 345 references for classification systems and 308 references for diagnosis methods, of which 283 and 295 were rejected due to off-topic abstract and/or failure to fulfil the inclusion criteria. After reading the remaining full-text articles, we included 27 articles describing classification systems and 13 articles describing diagnostic tests for acute isolated syndesmotic injuries.

CONCLUSIONS

The ESSKA-AFAS consensus panel recommends distinguishing acute isolated syndesmotic injury as stable or unstable. Stable injuries should be treated non-operatively with a short-leg cast or brace, while unstable injuries should be managed operatively. The recommended clinical tests include: tenderness on palpation over the anterior tibiofibular ligament, the fibular translation test and the Cotton test. Radiographic imaging must include an AP view and a mortise view of the syndesmosis to check the tibiofibular clear space, medial clear space overlap, tibial width and fibular width.

LEVEL OF EVIDENCE

IV.

Stable Versus Unstable Grade II High Ankle Sprains: A Prospective Study Predicting the Need for Surgical Stabilization and Time to Return to Sports

PURPOSE

To investigate grade II syndesmosis injuries in athletes and identify factors important in differentiating stable from dynamically unstable ankle sprains and those associated with a longer time to return to sports.

METHODS

Sixty-four athletes with an isolated syndesmosis injury (without fracture) were prospectively assessed, with a mean follow-up period of 37 months (range, 24 to 66 months). Those with an associated deltoid ligament injury or osteochondral lesion were included. Those whose injuries were considered stable (grade IIa) were treated conservatively with a boot and rehabilitation. Those whose injuries were clinically unstable underwent arthroscopy, and if instability was confirmed (grade IIb), the syndesmosis was stabilized. Clinical and magnetic resonance imaging assessments of injury to individual ligaments were recorded, along with time to return to play. A power analysis estimated that each group would need 28 patients.

RESULTS

All athletes returned to the same level of professional sport. The 28 patients with grade IIa injuries returned at a mean of 45 days (range, 23 to 63 days) compared with 64 days (range, 27 to 104 days) for those with grade IIb injuries (P < .0001). There was a highly significant relationship between clinical and magnetic resonance imaging assessments of ligament injury (anterior tibiofibular ligament [ATFL], anterior-inferior tibiofibular ligament [AITFL], and deltoid ligament, P < .0001). Instability was 9.5 times as likely with a positive squeeze test and 11 times as likely with a deltoid injury. Combined injury to the anterior-inferior tibiofibular ligament and deltoid ligament was associated with a delay in return to sports. Concomitant injury to the ATFL indicated a different mechanism of injury-the syndesmosis is less likely to be unstable and is associated with an earlier return to sports.

CONCLUSIONS

A positive squeeze test and injury to the ATFL and deltoid ligament are important factors in differentiating stable from dynamically unstable grade II injuries and may be used to identify which athletes may benefit from early arthroscopic assessment and stabilization. They may also be important in predicting the time frame for athletes' expected return to play.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

A rare type of ankle fracture: Syndesmotic rupture combined with a high fibular fracture without medial injury

High fibular spiral fractures are usually caused by pronation-external rotation mechanism. The foot is in pronation and the talus externally rotates, causing a rupture of the medial ligaments or a fracture of the medial malleolus. With continued rotation the anterior and posterior tibiofibular ligament will rupture, and finally, the energy leaves the fibula by creating a spiral fracture from anterior superior to posterior inferior. In this article we demonstrate a type of ankle fracture with syndesmotic injury and high fibular spiral fractures without a medial component. This type of ankle fractures cannot be explained by the Lauge-Hansen classification, since it lacks injury on the medial side of the ankle, but it does have the fibular fracture pattern matching the pronation external rotation injury (anterior superior to posterior inferior fracture). We investigated the mechanism of this injury illustrated by 3 cases and postulate a theory explaining the biomechanics behind this type of injury.

High Ankle Sprains and Syndesmotic Injuries in Athletes

Treatment of athletes with ligamentous injuries of the tibiofibular syndesmosis can be problematic. The paucity of historic data on this topic has resulted in a lack of clear guidelines to aid in imaging and diagnosing the injury, assessing injury severity, and making management decisions. In recent years, research on this topic has included an abundance of epidemiologic, clinical, and basic science investigations of syndesmotic injuries that are purely ligamentous or associated with ankle fracture. Several classification systems can be used to classify ligamentous injury to the syndesmosis. These systems integrate clinical and radiographic findings but do not address the location of the injury or its severity. Injury to the syndesmosis can be purely ligamentous; however, many unstable syndesmotic injuries are associated with fractures. Nonsurgical management can be used for stable ligamentous injuries without frank diastasis, but surgical management, including screw or suture-button fixation, is indicated for fractures with unstable syndesmotic injuries.