Ankle diastasis without fracture

Chronic syndesmotic instability - Current evidence on management

This review article discusses the current evidence on the management of chronic syndesmotic instability. Conservative treatment has a limited role, and surgical intervention is most commonly reported as the mainstay of treatment, however the literature consists of small case series and descriptions of operative techniques, and thus the evidence base for any treatment is weak. Surgical options include arthroscopic debridement alone, static fixation with cortical screws, dynamic fixation with suture-button devices, and ligamentous repair or augmentation.

Subtle Syndesmotic Instability

Latent or subtle syndesmotic instability is defined as an injury to the syndesmosis which is not apparent on static radiographs of the ankle. Syndesmotic injuries have also been referred to as high ankle sprains. Injury to the syndesmosis typically occurs with collision sports and often involves an external rotation force to the ankle. Diagnosis can be delayed because of negative initial imaging studies. Physical examination tests including the external rotation test, proximal squeeze test, and fibular shuck test can assist in the diagnosis. Advanced imaging modalities such as MRI and weight-bearing CT have been studied and can provide prognostic indications for management, although arthroscopic stress evaluation remains the benchmark for diagnosis. Both surgical and nonsurgical management techniques have been described, which can assist patients in returning to their preinjury level of function.

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.

Soft Tissue Pathology

A wide spectrum of pathologies can lead to soft tissue abnormalities within the ankle joint. Many of these disorders can develop into irreversible joint degeneration if left untreated. Arthroscopy is frequently used to treat these soft tissue conditions such as instability, synovitis, impingement, arthrofibrosis, and other inflammatory disorders in the rearfoot and ankle. In general, the etiology of these ankle soft tissue disorders can be classified as traumatic, inflammatory, and congenital/neoplastic. Overall, the goal of diagnosing and treating soft tissue pathologies of the ankle is to restore anatomic and physiologic motion, reduce pain, optimize functional return to activity, and decrease the chance of recurrence while minimizing complications.

Republication of "High-Speed Video Analysis of Syndesmosis Injuries in Soccer-Can It Predict Injury Mechanism and Return to Play? A Pilot Study"

Background

Ankle syndesmosis injuries in professional soccer may lead to an unpredictable and prolonged recovery. This injury has been investigated in anatomical and radiologic studies but the precise mechanism leading to syndesmosis injury is not well understood and remains debated. The 2 goals of this study were to (1) evaluate the relationship between the mechanism of syndesmosis injury as determined by high-speed video analysis and the injured structures identified by clinical and radiologic examination and to (2) investigate the relationship between mechanism of injury and time of return to play.

Methods

This pilot study prospectively reviewed high-speed video analysis of 12 professional soccer players who sustained syndesmosis injuries. The mechanism of injury was compared with the clinical and MRI evaluation and the time taken to return to play.

Results

Higher-grade syndesmosis injuries occurred during ankle external rotation with dorsiflexion. Supination-inversion injuries with a standard lateral ankle sprain (rupture of the anterior talofibular ligament) may extend proximally, causing a lower-grade syndesmosis injury. These may present with signs of a high ankle sprain but have a quicker return to sport than those following a dorsiflexion-external rotation injury (mean 26 days vs 91 days).

Conclusions

Video analysis confirmed that at least 2 mechanisms may result in injury to the ankle syndesmosis. Those "simple" ankle sprains with signs of syndesmosis injury had a quicker return to play. This new finding may be used by club medical teams during their initial assessment and help predict the expected time away from soccer in players with suspected high ankle sprains.

Level of Evidence

Level IV, retrospective cohort study.

Instability of the distal tibiofibular syndesmosis

The distal tibiofibular syndesmosis (DTFS) is more frequently injured than previously thought. Early diagnosis and appropriate treatment is essential to avoid long term complications like chronic instability, early osteoarthritis and residual pain. Management of these injuries require a complete understanding of the anatomy of DTFS, and the role played by the ligaments stabilizing the DTFS and ankle. High index of suspicion, appreciating the areas of focal tenderness and utilizing the provocative maneuvers help in early diagnosis. In pure ligamentous injuries radiographs with stress of weight bearing help to detect subtle instability. If these images are inconclusive, then further imaging with MRI, CT scan, stress examination under anesthesia, and arthroscopic examination facilitate diagnosis. An injury to syndesmosis frequently accompanies rotational fractures and all ankle fractures need to be stressed intra-operatively under fluoroscopy after fixation of the osseous components to detect syndesmotic instability. Non-operative treatment is appropriate for stable injuries. Unstable injuries should be treated operatively. Anatomic reduction of the syndesmosis is critical, and currently both trans-syndesmotic screws and suture button fixation are commonly used for syndesmotic stabilization. Chronic syndesmotic instability (CSI) requires debridement of syndesmosis, restoration of ankle mortise with or without syndesmotic stabilization. Arthrodesis of ankle is used a last resort in the presence of significant ankle arthritis. This article reviews anatomy and biomechanics of the syndesmosis, the mechanism of pure ligamentous injury and injury associated with ankle fractures, clinical, radiological and arthroscopic diagnosis and surgical treatment.

Ankle syndesmotic reconstruction in chronic ankle syndesmotic injury

Acute syndesmotic injury is a common problem treated with different surgical tools. If not managed appropriately, it can lead to chronic ankle syndesmotic insufficiency. Chronic syndesmotic insufficiency is challenging to diagnose, and the patient can suffer for a long time. There is no consensus in previous literature on the surgical treatment of chronic syndesmotic injury. We present a case of personnel who suffered from chronic syndesmotic injury treated by syndesmotic reconstruction 5 years after his ankle fracture dislocation and returned to his work. This case highlights the importance of a CT scan post-reduction of an acute syndesmotic injury to assess accurate reduction, especially in severe injuries with frank diastasis.

Acute Syndesmosis Injuries

Ankle syndesmosis injuries include isolated ligamentous rupture, as well as fractures with ligamentous injury. These injuries can significantly affect athletes in all sports, and lead to prolonged recovery and return to sport. Adequate evaluation and diagnosis of these injuries are imperative for treatment and return to play. Many can be treated nonoperatively, but operative treatment is indicated in fractures with syndesmosis disruption and ligamentous injuries with instability. Anatomic reduction and fixation of these injuries will allow functional rehab and return to sport.

Biomechanical Analysis of Tibiofibular Syndesmosis Injury Fixation Methods: A Finite Element Analysis

The optimal treatment strategy after syndesmotic injuries is still controversial. In our study, we aimed to evaluate ideal fixation method in syndesmotic injury by using finite element analysis method. A 3D SolidWorks model file was created by taking computed tomography (CT) images of the area from the right foot base to the knee joint level of a healthy adult male. The intact model, injury model, and 8 different fixation models were created that 3.5 mm screw and suture-button were used in. The models were compared in terms of lateral fibular translation, posterior fibular translation and external rotation of fibula compared to tibia and stress values occurred on screws and suture-buttons. In the hybrid-1 model, lateral fibular translation and external fibular rotation values were obtained as close to the intact model. Von Mises stresses occurred in the screw (435.7 MPa) and suture-button (424.7 MPa) that used in hybrid-1 model was more than single screw at 4 cm model (316.8 MPa) and single suture-button at 2 cm model (160.7 MPa). In the Hybrid-1 model, the screw compensates for posterior fibular translation and external fibular rotation, while the suture-button compensates for lateral fibular translation. Also, the effect of the distal suture-button preventing diastasis in case of proximal screw failure, it was concluded that the hybrid-1 model can be used as a good treatment alternative in the surgical treatment of distal tibiofibular syndesmotic injuries.

3D Mapping of the Lateral Malleolus Fractures for Predicting Syndesmotic Injuries in Supination External Rotation Type Ankle Fractures

Supination external rotation (SER) type ankle fracture is the most common ankle fracture in the Lauge-Hansen classification and is often accompanied with syndesmotic injury. However, the mechanism of this injury is indistinct and a suggestive role can be given by preoperative imaging. This study was to preoperatively predict whether SER type ankle fractures are accompanied with syndesmotic injuries by the means of lateral malleolus fracture mapping. One hundred and forty-eight patients diagnosed with SER type ankle fractures were retrospectively enrolled in this study. The baseline data were collected and computed tomography data were reconstructed in 3-dimensional (3D) model. Patients were divided into stable and unstable groups according to intraoperative Cotton test and whether the inferior tibiofibular screw was placed. All fracture lines were superimposed on the ankle template to create a fracture map, and the data on the fracture map were further measured. Logistic regression was conducted to identify relevant factors and the cutoff values were given using receiver operating characteristic curves. Forty-one patients were enrolled in the unstable group and 107 patients were enrolled in the stable group. The lateral malleolus fracture lines of the unstable group were higher and steeper than that in the stable group on lateral and posterior views. The fracture height of the posterior cortex and peak height were the significant contributing factors, and the cut-off values of posterior cortex, peak height and inclination angle were 40.35 mm (sensitivity: 78%, specificity: 82%), 55.34 mm (sensitivity: 85%, specificity: 70%) and 55.6° (sensitivity: 66%, specificity: 86%), respectively. In general, when the fracture lines of the lateral malleolus were high and steep, it was usually indicative of a syndesmotic injury and can be predicted by the preoperative 3D reconstruction of fracture height of posterior cortex, peak height and inclination angle. If the cut-off values of these indicators are exceeded, the syndesmotic injuries may be presented and need to be verified in the intraoperative Cotton test to decide whether to insert an inferior tibiofibular screw.

A systematic review of ankle fracture-dislocations: Recent update and future prospects

Background

Ankle fracture-dislocations are one of the most severe types of ankle injuries. Compared to the simple ankle fractures, ankle fracture-dislocations are usually more severely traumatized and can cause worse functional outcomes. The purpose of this study was to review the previous literatures to understand the anatomy, mechanisms, treatment, and functional outcomes associated with ankle fracture-dislocations.

Methods

The available literatures from January 1985 to December 2021 in three main medical databases were searched and analyzed. The detailed information was extracted for each article, such as researchers, age, gender, groups, type of study, type of center research, level of evidence, significant findings, study aim, cause of injury, time from injury to surgery, type of fracture, direction of dislocation, follow-up, postoperative complications and functional evaluation scores.

Results

A total of 15 studies (1,089 patients) met the inclusion criteria. Only one study was a prospective randomized trial. The top-ranked cause of injury was high-energy injury (21.3%). Moreover, the most frequent type of fracture in ankle dislocations was supination-external rotation (SER) ankle fracture (43.8%), while the most common directions of dislocation were lateral (50%) and posterior (38.9%).

Conclusions

Collectively, most ankle fracture-dislocations are caused by high-energy injuries and usually have poor functional outcomes. The mechanism of injury can be dissected by the ankle anatomy and Lauge-Hansen's classification. The treatment of ankle fracture-dislocations still requires more detailed and rational solutions due to the urgency of occurrence, the severity of injury, and the postoperative complications.

Return to Play After Isolated Syndesmotic Ligamentous Injury in Athletes: A Systematic Review and Meta-analysis

Background:

Syndesmotic ankle sprains are common and challenging injuries for athletes. The management of such injuries is controversial, with a paucity of evidence on treatment protocols with unpredictability regarding the time lost to participate in sports following injury. The present study seeks to review and report the return to play (RTP) time and examine the outcomes and complications of ankle syndesmotic sprains in the athletic population.

Methods:

PubMed, Cochrane Library, and Google Scholar were queried in August 2021 for case series, cohorts, and randomized controlled trials that evaluated return to play time after ankle syndesmotic sprains. The primary outcomes were the rate and time to return to play after syndesmotic ankle sprains for both surgical and nonsurgical treatment. Secondary outcomes included short-term complications and recurrence.

Results:

Eighteen articles were eligible for meta-analysis with a total of 1133 syndesmotic sprains. The overall RTP was 99% (95% CI 0.96, 1.00), the overall mean RTP was 52.32 days (95% CI 39.01, 65.63). Pooled RTP for surgically treated patients was 70.94 days (95% CI 47.04, 94.85), whereas it was 39.33 days (95% CI 28.78, 49.88) for nonsurgically treated cases. A low incidence of recurrence and complications were reported.

Conclusion:

This article reports a high rate of RTP after syndesmotic sprains. Grade of injury and surgical vs conservative management can affect the time to RTP in high-level athletes.

Level of Evidence: Level IV, systematic review and meta-analysis.

Maisonneuve Fractures of the Ankle: A Critical Analysis Review

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Maisonneuve fractures (MFs), originally described as subcapital (high) fibular fractures with additional injury to the anterior and interosseous tibiofibular ligaments, display a variable injury pattern, ranging from stable to highly unstable fractures.

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The high incidence of associated fractures of the posterior malleolus, the medial malleolus, and the anterolateral distal tibia (the "anterior malleolus") as well as the variable position of the fibula in the fibular notch (FN) warrant preoperative examination via computed tomography (CT).

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The main goal of treatment is anatomic reduction of the distal fibula into the FN, which requires prior reduction of displaced posterior malleolar fractures, if present, to restore the integrity of the FN.

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Open reduction of the distal fibula into the FN and fixation with 2 transsyndesmotic screws or fixation with a screw(s) and suture-button implant, under direct vision, on the lateral aspect of the ankle joint and anterior tibiofibular alignment are preferred over closed reduction to avoid sagittal or rotational malpositioning, which is associated with an inferior outcome.

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Intra- or postoperative 3D CT visualization is essential for assessment of the accuracy of the reduction of the distal fibula into the FN.

Does Malrotation After Minimally Invasive Plate Osteosynthesis Treatment of Distal Tibia Metaphyseal Fractures Effect the Functional Results of the Ankle and Knee Joints?

OBJECTIVES

To investigate whether rotational malalignment of tibia, after fracture management with minimally invasive plate osteosynthesis technique (MIPO), leads to impaired results in knee and ankle joint functional scores.

DESIGN

Prospectively collected data were retrospectively analyzed for this study.

SETTING

Level III academic trauma center.

PATIENTS/PARTICIPANTS

Sixty-five consecutive patients who applied between October 2010 and January 2014 with a unilateral distal tibia fracture and had full bone union at their last visit were analyzed. Patients were excluded if they had a pathologic fracture, Gustilo-Anderson type II or III open fracture, additional ligamentous trauma, were pregnant, or had any deformity. A total of 27 patients were accepted into the study.

INTERVENTION

All patients were treated with a MIPO technique after a mean of 2.8 days. The fibular fracture, when present, was fixed first.

MAIN OUTCOME MEASUREMENTS

The main outcome of this study was the relation between tibial malrotation after a MIPO procedure, and Lower Extremity Functional Scale, American Orthopedic Foot and Ankle Society, KOOS scores, and range of motions of adjacent joints.

RESULTS

Fourteen patients (51.8%) had a rotation higher than 10 degrees. The mean malrotation angle was 14.6 degrees. Concomitant fibular fractures were present in 13 patients, which did not seem to have a significant influence on malrotation. There was no significant difference between groups regarding functional scores and range of motions of the knee and ankle joints.

CONCLUSIONS

Despite high rates of malrotation after tibial metaphyseal-diaphyseal fractures treated with MIPO technique, this finding does not seem to have a significantly negative effect on knee and ankle joint functions. Meticulous intraoperative evaluation, through a range of different techniques, should be performed to avoid malrotation.

LEVEL OF EVIDENCE

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

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.

Deep deltoid ligament injury is related to rotational instability of the ankle joint: a biomechanical study

PURPOSE

In the athletic population, the prevalence of isolated syndesmotic lesions is high. To detect potential instability of the ankle is crucial to define those lesions in need of surgical management. The aim was to define how the extent of tibio-fibular syndesmotic ligament injury influences the overall stability of the ankle joint in a cadaver model.

METHODS

Twenty fresh-frozen through knee cadaveric leg specimens were subjected to different simulated syndesmotic ligament lesions. In Group 1 (n = 10), the order of ligament sectioning was: anterior tibio-fibular ligament (ATFL), superficial deltoid ligament (SDL), deep deltoid ligament (DDL), posterior tibio-fibular ligament (PTFL), and progressive sectioning at 10, 50 and 100 mm of the distal interosseous membrane (IOM). In Group 2 (n = 10), the sequence was: ATFL, PITFL, 10 and then 50 mm of the distal IOM, SDL, DDL, and 100 mm of the distal IOM. Diastasis of 4 mm in the coronal or sagittal plane and external rotation of the ankle greater than 20° were considered indicative of instability.

RESULTS

Both coronal and sagittal diastasis exceeded 4 mm with injury patterns characterized by IOM lesions extending beyond 5 cm. External rotation of the ankle exceeded 20° with injury patterns characterized by a DDL lesion.

CONCLUSION

Coronal and sagittal plane diastases of the tibio-fibular syndesmosis are particularly affected by sequential lesions involving the IOM, whereas increased external rotation of the ankle most depends on DDL. The identification of the specific syndesmotic and deltoid ligament injuries is crucial to understanding which lesions need operative management. The knowledge of which pattern of tibio-fibular syndesmotic ligament injury influences the ankle joint stability is crucial in defining which lesions need for surgical management.

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.

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.

Chronic Syndesmotic Injuries: Arthrodesis versus Reconstruction

"Chronic syndesmotic injury covers a broad range of symptoms and pathologies. Anterolateral ankle impingement without instability is treated by arthroscopic debridement. Subacute, unstable, syndesmotic injuries are treated by arthroscopic or open debridement followed by secondary stabilization using suture button device or permanent screw placement. Chronic syndesmotic instability is treated by a near-anatomic ligamentoplasty supplemented by screw fixation. In case of poor bone stock, failed ligament reconstruction, or comorbidities, tibiofibular fusion with bone grafting is preferred. Malleolar malunions and particularly anterior or posterior syndesmotic avulsions must be corrected in order to achieve a stable and congruent ankle mortise."

Clinical outcome of distal tibiofibular arthrodesis with plate fixation for the treatment of chronic frank syndesmosis instability

BACKGROUND

Numerous treatment strategies have been reported for the treatment of chronic frank distal tibiofibular syndesmosis instability, including several small case series treated by syndesmosis arthrodesis. The aim of this study is to report the treatment of this condition using a specially contoured plate and the associated clinical outcomes.

METHODS

Over a period of 8 years, patients presented in our institution with chronic frank distal tibiofibular syndesmosis instability were eligible to participate. All patients were managed with plating and screw fixation. The average follow-up period was 58 months (range, 12-99). Clinical outcome was evaluated using the American Orthopaedic Foot & Ankle Society ankle-hindfoot score.

RESULTS

In total, 8 patients met the inclusion criteria and formed the basis of this study. All patients could tolerate full weightbearing 3 months after surgery. The mean Visual Analog Scale pain score and the American Orthopaedic Foot & Ankle Society ankle-hindfoot score were significantly improved at the last follow-up (P<0.05). All patients were satisfied with the result and 7 patients returned to sports. 4 patients had mild limitation of ankle range of motion compared with the unaffected side.

CONCLUSION

Syndesmosis arthrodesis was a feasible method for the treatment of chronic frank syndesmosis instability according to our findings. Syndesmosis arthrodesis with plate and screw stabilization is another viable option to be considered into the surgeon's armamentarium. Larger scale studies are desirable to provide further evidence of this method of treatment.

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.

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.

Anatomic Ligament Repairs of Syndesmotic Injuries

Poor clinical results are seen with syndesmotic injuries in the setting of ankle sprains and ankle fractures. The goal of syndesmosis repair is to restore the normal anatomic relationship of the distal tibiofibular joint and prevent ankle arthritis. Indications for surgical intervention for isolated syndesmotic injuries include frank syndesmosis diastasis, medial clear space widening on plain radiographs, significant radiographic syndesmosis diastasis during stress examination, or subtle syndesmotic diastasis detected by arthroscopic evaluation. Complications after syndesmosis repair include symptomatic hardware, malreduction, and arthritis. Anatomic reduction of the syndesmosis leads to better outcomes following surgery.

High-Speed Video Analysis of Syndesmosis Injuries in Soccer—Can It Predict Injury Mechanism and Return to Play? A Pilot Study

Background:

Ankle syndesmosis injuries in professional soccer may lead to an unpredictable and prolonged recovery. This injury has been investigated in anatomical and radiologic studies but the precise mechanism leading to syndesmosis injury is not well understood and remains debated. The 2 goals of this study were to (1) evaluate the relationship between the mechanism of syndesmosis injury as determined by high-speed video analysis and the injured structures identified by clinical and radiologic examination and to (2) investigate the relationship between mechanism of injury and time of return to play.

Methods:

This pilot study prospectively reviewed high-speed video analysis of 12 professional soccer players who sustained syndesmosis injuries. The mechanism of injury was compared with the clinical and MRI evaluation and the time taken to return to play.

Results:

Higher-grade syndesmosis injuries occurred during ankle external rotation with dorsiflexion. Supination-inversion injuries with a standard lateral ankle sprain (rupture of the anterior talofibular ligament) may extend proximally, causing a lower-grade syndesmosis injury. These may present with signs of a high ankle sprain but have a quicker return to sport than those following a dorsiflexion-external rotation injury (mean 26 days vs 91 days).

Conclusions:

Video analysis confirmed that at least 2 mechanisms may result in injury to the ankle syndesmosis. Those “simple” ankle sprains with signs of syndesmosis injury had a quicker return to play. This new finding may be used by club medical teams during their initial assessment and help predict the expected time away from soccer in players with suspected high ankle sprains.

Level of Evidence:

Level IV, retrospective cohort study.

Arthroscopic Treatment of Ankle Arthritis

Ankle arthritis can be broadly classified as primary arthritis (nontraumatic degeneration) or secondary arthritis (post-traumatic degeneration). A good understanding of the anatomic features and presentations associated with each will assist the surgeon in determining the best course of action for each patient. Many variations of both primary and secondary arthritis can be treated conservatively; however, there are many times when conservative therapy is not adequate. In these cases, ankle arthroscopy may be considered before a joint fusion or replacement. Here, the authors discuss the common types of ankle arthritis, their presentations, and treatment success with ankle arthroscopy.

Medial Clamp Tine Positioning Affects Ankle Syndesmosis Malreduction

OBJECTIVES

To determine whether the position of the medial clamp tine during syndesmotic reduction affected reduction accuracy.

DESIGN

Prospective cohort.

SETTING

Urban Level 1 trauma center.

PATIENTS

Seventy-two patients with operatively treated syndesmotic injuries.

INTERVENTION

Patients underwent operative fixation of their ankle syndesmotic injuries using reduction forceps. The position of the medial clamp tine was then recorded with intraoperative fluoroscopy. Malreduction rates were then assessed with bilateral ankle computerized tomography.

MAIN OUTCOME MEASUREMENT

Fibular position within the incisura was measured with respect to the uninjured side to determine whether a malreduction had occurred. Malreductions were then analyzed for associations with injury pattern, patient demographics, and the location of the medial clamp tine.

RESULTS

A statistically significant association was found between medial clamp position and sagittal plane syndesmosis malreduction. In reference to anterior fibular translation, there was a 0% malreduction rate in the 18 patients where the clamp tine was placed in the anterior third, a 19.4% malreduction rate in the middle third, and 60% malreduction rate in the posterior third (P = 0.006). In reference to posterior fibular translation, there was a 11.1% malreduction when clamp placement was in the anterior third, a 16.1% malreduction rate in the middle third, and 60% malreduction rate in the posterior third (P = 0.062). There were no significant associations between medial clamp position and coronal plane malreductions (overcompression or undercompression) (P = 1).

CONCLUSIONS

When using reduction forceps for syndesmotic reduction, the position of the medial clamp tine can be highly variable. The angle created with off-axis syndesmotic clamping is likely a major culprit in iatrogenic malreduction. Sagittal plane malreduction appears to be highly sensitive to clamp obliquity, which is directly related to the medial clamp tine placement. Based on these data, we recommend placing the medial clamp tine in the anterior third of the tibial line on the lateral view to minimize malreduction risk.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Maisonneuve Equivalent Injury With Proximal Tibiofibular Joint Dislocation: Case Report and Literature Review

We report the case of a 31-year-old male who presented with traumatic dislocation of both proximal and distal tibiofibular joints without fibular fracture. The patient underwent closed reduction of the proximal tibiofibular joint and surgical stabilization of the distal tibiofibular joint. An 18-month postoperative evaluation confirmed a very good clinical outcome after anatomic reduction. This type of trauma is very rare and, to our knowledge, has only been described 3 times previously. Furthermore, our surgical management was different from that used for the previous cases and proved to be satisfactory.

A new assessment for syndesmosis injury - The 'Chertsey test'

INTRODUCTION

If a syndesmosis injury is not detected, or not treated appropriately, it can lead to pain and arthritis. Various techniques have been described to look for the presence of a syndemosis injury. If concern is raised regarding malreduction, the most recognised way of checking accuracy of the reduction (of the fibula into the incisura) is bilateral postoperative ankle CT scans. This not only exposes the patient to further radiation, but can normally only be done once the surgery is completed and so if adjustment is needed, this requires a further operation, encompassing further surgical risks. We developed a simple assessment, which both gives accurate intra-operative demonstration of an injury to the syndesmosis and also can check how well the fibula has been reduced (if required), without the need for further radiological investigation or surgical intervention. The objectives were to test how easy it was to perform the test and apply it to a number of different ankle fractures.

METHODS

Peri-operatively, 2-4ml of contrast medium was injected into the ankle joint in cases where there was concern about injury to the syndesmosis. If there was a 'positive' test, and a 'blush' of dye leaked into the surrounding soft tissues, then fixation of the syndesmosis was performed (as per the surgeon's preferred technique). After fixation was completed, a further injection of contrast medium was injected to see if the fibular had been anatomically reduced into its incisura. The test was performed on 15 ankles.

RESULTS

There were no difficulties in performing the test and no complications reported. The test clearly demonstrated where there had been an injury to the syndesmosis and also confirmed the accurate reduction of the fibula when there had been stabilisation of the syndesmosis.

CONCLUSIONS

It has proved to be an easy and reliable adjunct to ankle fixation surgery and may have further indications.

Isolated syndesmotic injuries in acute ankle sprains: diagnostic significance of clinical examination and MRI

PURPOSE

Acute ankle sprains are frequently accompanied by syndesmotic injuries. These injuries are often overlooked in clinical examinations. The aim of this study was (1) to evaluate the incidence of syndesmotic injuries in acute ankle sprains using MRI, (2) to determine the accuracy of common clinical diagnostic tests, (3) to analyse their inter-rater reliability, and (4) to evaluate the role of clinical symptoms in the diagnosis of syndesmotic injuries.

METHODS

A total of 100 patients with acute ankle sprain injury without associated fractures in plane radiographs were enrolled. The clinical assessment was performed by two independent examiners. Local findings, ankle ligament palpation, squeeze test, external rotation test, Drawer test, Cotton test, and the crossed-leg test (two examiners) were compared with MRI results (read by two blinded radiologists) as a reference standard.

RESULTS

Ninety-six participants (57% male) met the inclusion criteria. MRI detected a ruptured anterior inferior tibiofibular ligament (AITFL) in 14 patients (15%); 9 partial tears and 5 complete tears were evident. Evidence of pain at rest was found to predict syndesmotic injuries most accurately (p = 0.039). The palpation test over the proximal fibula produced the highest inter-rater correlation (κ = 0.65), but the lowest sensitivity for syndesmotic injuries of 8%. All other clinical tests demonstrated moderate to fair inter-rater reliabilities (κ = 0.37-0.52). Low sensitivity values were found with all clinical tests (13.9-55.6%).

CONCLUSION

In this study, clinical examination was insufficient to detect syndesmotic injuries in acute ankle sprains. MRI scanning revealed a syndesmotic lesion in 15% of patients. MRI scanning should be recommended in patients with ongoing pain at rest following ankle sprains.

LEVEL OF EVIDENCE

I.

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.

Conservative and surgical management of acute isolated syndesmotic injuries: ESSKA-AFAS consensus and guidelines

PURPOSE

Correct management of syndesmotic injuries is mandatory to avoid scar tissue impingement, chronic instability, heterotopic ossification, or deformity of the ankle. The aim of the present study was to perform a systematic review of the current treatments of these injuries to identify the best non-surgical and surgical management for patients with acute isolated syndesmotic injuries.

METHODS

A review of the literature was performed according to the PRISMA guidelines. A comprehensive search of PubMed, Medline, CINAHL, Cochrane, Embase, and Google Scholar databases was performed using the following keywords: "ankle injury", "syndesmotic injury", "chronic", "acute", "treatment", "conservative", "non-operative" "operative", "fixation", "osteosynthesis", "screw", "synostosis", "ligamentoplasties" over the years 1962-2015.

RESULTS

The literature search and cross-referencing resulted in a total of 345 references, of which 283 were rejected due to off-topic abstract and/or failure to fulfil the inclusion criteria. After reading the remaining full-text articles, we included four studies, describing non-surgical management, and only two studies investigating surgical management of acute isolated injuries.

CONCLUSIONS

The ESSKA-AFAS consensus panel provided recommendations to improve the management of patients with isolated acute syndesmotic injury in clinical practice. Non-surgical management is recommended for stable ankle lesions and includes: 3-week non-weight bearing, a below-the-knee cast, rest and ice, followed by proprioceptive exercises. Surgery is recommended for unstable lesions. Syndesmotic screw is recommended to achieve a temporary fixation of the mortise. Suture-button device can be considered a viable alternative to a positioning screw. Partial weight bearing is allowed 6 weeks after surgery.

LEVEL OF EVIDENCE

IV.

Outcomes and Return to Activity After Operative Repair of Chronic Latent Syndesmotic Instability

BACKGROUND

This study is a retrospective review of prospectively gathered data determining the postoperative outcomes of patients who underwent operative treatment to address chronic syndesmotic instability.

METHODS

The cohort is composed of 19 individuals who elected to undergo operative treatment of chronic syndesmotic instability. The operative repair consisted of arthroscopic debridement in all cases with reduction and suture button fixation of those patients who had greater than 4 mm of syndesmotic diastasis on arthroscopic evaluation. All patients had a minimum of 24 months follow-up. This study retrospectively examined the prospectively gathered preoperative and postoperative outcome scores to include a Visual Analog Scale (VAS) pain score and an American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score. In addition, patients were questioned on their ability to return to their preinjury level of activity and their ability to continue running sports. Fourteen patients returned their postoperative surveys.

RESULTS

Mean AOFAS scores improved significantly from 48 to 82.7 (P = .014). Mean VAS scores improved from 6.1 to 1.0 (P = .002). Overall, 86% (12/14) of patients were able to return to running and 79% (11/14) of patients were able to return to their preinjury level of sport. Preoperative and postoperative weight-bearing ankle radiographs were reviewed to evaluate the tibiofibular clear space and overlap. The clear space measured on anteroposterior (AP) radiographs decreased from 5.4 mm to 4.6 mm (P = .005), the clear space evaluated on the mortise radiograph decreased from 4.5 mm to 3.6 mm (P = .006), and the overlap measured on the AP radiograph increased from 5.7 mm to 6.9 mm (P = .019). All radiographs were measured by a board-certified musculoskeletal radiologist.

CONCLUSION

This study presents a treatment method that can be instituted at the time of diagnosis for syndesmotic injuries with greater than 4 mm of diastasis that were treated with debridement and stabilization. The results of this treatment technique are promising, with significant improvements in subjective outcome scores and a high rate of return to running sports.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Plasma rich in growth factors (PRGF) as a treatment for high ankle sprain in elite athletes: a randomized control trial

PURPOSE

Syndesmotic sprains are uncommon injuries that require prolonged recovery. The influence of ultrasound-guided injections of platelet-rich plasma (PRP) into the injured antero-inferior tibio-fibular ligaments (AITFL) in athletes on return to play (RTP) and dynamic stability was studied.

METHODS

Sixteen elite athletes with AITFL tears were randomized to a treatment group receiving injections of PRP or to a control group. All patients followed an identical rehabilitation protocol and RTP criteria. Patients were prospectively evaluated for clinical ability to return to full activity and residual pain. Dynamic ultrasound examinations were performed at initial examination and at 6 weeks post-injury to demonstrate re-stabilization of the syndesmosis joint and correlation with subjective outcome.

RESULTS

All patients presented with a tear to the AITFL with dynamic syndesmosis instability in dorsiflexion-external rotation, and larger neutral tibia-fibula distance on ultrasound. Early diagnosis and treatment lead to shorter RTP, with 40.8 (±8.9) and 59.6 (±12.0) days for the PRP and control groups, respectively (p = 0.006). Significantly less residual pain upon return to activity was found in the PRP group; five patients (62.5 %) in the control group returned to play with minor discomfort versus one patient in the treatment group (12.5 %). One patient in the control group had continuous pain and disability and subsequently underwent syndesmosis reconstruction.

CONCLUSIONS

Athletes suffering from high ankle sprains benefit from ultrasound-guided PRP injections with a shorter RTP, re-stabilization of the syndesmosis joint and less long-term residual pain.

LEVEL OF EVIDENCE

II.

Stress shielding in the bony chain of leg in presence of varus or valgus knee

AIMS

The aim was to assess how the stress shielding can influence the integrity and resistance of bones in presence of a misalignment.

METHODS

Three finite elements models have been developed: a normal one, and two varus and valgus knee ones.

RESULTS

The obtained results reveal interesting consequences deriving by a wrong disposition of parts which compose the skeletal chain of the leg.

CONCLUSION

The most dangerous conditions occur in the contact interface between pelvis and hip of the femur, for the valgus knee configuration, and for the varus one, at the contact interface around the knee zone.

Deltoid ligament repair versus syndesmotic fixation in bimalleolar equivalent ankle fractures

OBJECTIVES

To compare the outcomes of bimalleolar equivalent ankle fractures treated with lateral malleolus open reduction and internal fixation (ORIF) with transsyndesmotic fixation versus lateral malleolus ORIF with deltoid ligament repair.

DESIGN

Retrospective design.

SETTING

Single level I trauma center.

PATIENTS/PARTICIPANTS

Subjects with bimalleolar equivalent ankle fractures were eligible for enrollment. Patients with posterior or medial malleolar fractures and age <16 years were excluded. Twenty-seven total subjects met inclusion criteria. Fifteen patients were treated with lateral malleolus ORIF with transsyndesmotic fixation, whereas 12 were treated with lateral malleolus ORIF with deltoid ligament repair.

INTERVENTION

Lateral malleolus ORIF with transsyndesmotic fixation versus lateral malleolus ORIF with deltoid ligament repair.

MAIN OUTCOME MEASUREMENTS

Lower Extremity Function Scale, Foot and Ankle Disability Index, Short Musculoskeletal Function Assessment, Foot and Ankle Outcome Score, American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale, Visual Analog Pain Scale, and overall function of lower extremity.

RESULTS

Univariate analysis of the outcome questionnaire variables demonstrated no statistically significant differences between the 2 groups. All patients in the syndesmotic fixation group underwent a subsequent procedure for removal of the syndesmotic implant. Additionally, there were 2 complications in the syndesmotic group that required repeat operative intervention.

CONCLUSIONS

Repairing the deltoid ligament at the time of lateral malleolus fixation demonstrates subjective, functional, and radiologic outcomes that are comparable with lateral malleolus fixation with syndesmotic fixation for bimalleolar equivalent ankle fractures. The former avoids the costs and inherits surgical risks that occur during a subsequent operation for removal of the syndesmotic implant.

LEVEL OF EVIDENCE

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

Ankle syndesmosis: a qualitative and quantitative anatomic analysis

BACKGROUND

Syndesmosis sprains can contribute to chronic pain and instability, which are often indications for surgical intervention. The literature lacks sufficient objective data detailing the complex anatomy and localized osseous landmarks essential for current surgical techniques.

PURPOSE

To qualitatively and quantitatively analyze the anatomy of the 3 syndesmotic ligaments with respect to surgically identifiable bony landmarks.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Sixteen ankle specimens were dissected to identify the anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), interosseous tibiofibular ligament (ITFL), and bony anatomy. Ligament lengths, footprints, and orientations were measured in reference to bony landmarks by use of an anatomically based coordinate system and a 3-dimensional coordinate measuring device.

RESULTS

The syndesmotic ligaments were identified in all specimens. The pyramidal-shaped ITFL was the broadest, originating from the distal interosseous membrane expansion, extending distally, and terminating 9.3 mm (95% CI, 8.3-10.2 mm) proximal to the central plafond. The tibial cartilage extended 3.6 mm (95% CI, 2.8-4.4 mm) above the plafond, a subset of which articulated directly with the fibular cartilage located 5.2 mm (95% CI, 4.6-5.8 mm) posterior to the anterolateral corner of the tibial plafond. The primary AITFL band(s) originated from the tibia 9.3 mm (95% CI, 8.6-10.0 mm) superior and medial to the anterolateral corner of the tibial plafond and inserted on the fibula 30.5 mm (95% CI, 28.5-32.4 mm) proximal and anterior to the inferior tip of the lateral malleolus. Superficial fibers of the PITFL originated along the distolateral border of the posterolateral tubercle of the tibia 8.0 mm (95% CI, 7.5-8.4 mm) proximal and medial to the posterolateral corner of the plafond and inserted along the medial border of the peroneal groove 26.3 mm (95% CI, 24.5-28.1 mm) superior and posterior to the inferior tip of the lateral malleolus.

CONCLUSION

The qualitative and quantitative anatomy of the syndesmotic ligaments was reproducibly described and defined with respect to surgically identifiable bony prominences.

CLINICAL RELEVANCE

Data regarding anatomic attachment sites and distances to bony prominences can optimize current surgical fixation techniques, improve anatomic restoration, and reduce the risk of iatrogenic injury from malreduction or misplaced implants. Quantitative data also provide the consistency required for the development of anatomic reconstructions.

An update on the evaluation and treatment of syndesmotic injuries

INTRODUCTION

Injuries to the distal tibiofibular syndesmosis are frequent and continue to generate controversy.

METHODS

The majority of purely ligamentous injuries ("high ankle sprains") is not sassociated with a latent or frank tibiofibular diastasis and may be treated with an extended protocol of physical therapy. Relevant instability of the syndesmosis with diastasis results from rupture of two or more ligaments that require surgical stabilization. Syndesmosis disruptions are commonly associated with bony avulsions or malleolar fractures. Treatment consists in anatomic reduction of the distal fibula into the corresponding incisura of the distal tibia and stable fixation. Proposed means of fixation are refixation of bony syndesmotic avulsions, one or two tibiofibular screws and suture button. There is no consensus on how long to maintain fixation. Both syndesmotic screws and suture buttons need to be removed if symptomatic.

RESULTS/COMPLICATIONS

The most frequent complication is syndesmotic malreduction and may be minimized with open reduction and intraoperative 3D scanning. Other complications include hardware failure, heterotopic ossification, tibiofibular synostosis, chronic instability and posttraumatic arthritis.

CONCLUSION

The single most important prognostic factor is anatomic reduction of the distal fibula into the tibial incisura.

Evaluation and treatment recommendations for acute injuries to the ankle syndesmosis without associated fracture

Ankle ligamentous injuries are commonly seen in athletes in a variety of sports. Surveys of physicians and trainers of professional sports teams have identified syndesmotic injuries as among the most difficult to treat. In particular, injuries of the ankle syndesmosis have been strongly linked with a prolonged recovery and increased time to return to play. Due to sudden external rotation with the tibiotalar joint in dorsiflexion, these structures are commonly injured in association with fractures of the distal fibula. Surgery is indicated in cases with associated fractures and ligamentous instability, but optimal treatment for syndesmosis injuries without an associated fracture is less clear. A thorough history and physical examination, as well as appropriate imaging, are necessary to effectively diagnose and classify the injury. For stable injuries, short-term immobilization and functional rehabilitation is recommended. Unstable Grade 2 and 3 injuries require surgical fixation. Debate currently exists over rigid screw fixation versus suture button techniques as the ideal fixation method.

Evaluation and management of injuries of the tibiofibular syndesmosis

INTRODUCTION

Injury to the tibiofibular syndesmosis often arises from external rotation force acting on the foot leading to eversion of the talus within the ankle mortise and increased dorsiflexion or plantar flexion. Such injuries can present in the absence of a fracture. Therefore, diagnosis of these injuries can be challenging, and often stress radiographs are helpful. Magnetic resonance imaging scans can be a useful adjunct in doubtful cases. The management of syndesmotic injuries remains controversial, and there is no consensus on how to optimally fix syndesmosis. This article reviews the mechanism of injury, clinical features and investigations performed for syndesmotic injuries and brings the reader up-to-date with the current evidence in terms of the controversies surrounding the management of these injuries.

SOURCES OF DATA

Embase, Pubmed Medline, Cochrane Library, Elsevier and Google Scholar (January 1950-2014).

AREAS OF CONTROVERSY

The management of syndesmotic injuries remains controversial, and there is no consensus on: (i) which ankle fractures require syndesmotic fixation, (ii) the number or the size and the type of screws that should be used for fixation, (iii) how many cortices to engage for fixation, (iv) the level of screw placement above the ankle plafond, (v) the duration for which the screw needs to remain in situ to allow the tibiofibular syndesmosis to heal and (vi) when should patients weight bear.

AREAS OF AGREEMENT

(i) A high proportion of syndesmotic fixations demonstrates malreduction of the syndesmosis, (ii) no need to remove screws routinely, (iii) two screws appear to better one alone and (iv) if syndesmosis injury is not detected or not treated long term, it leads to pain and arthritis.

GROWING POINTS

(i) How to assess the adequacy of syndesmotic reduction using imaging in the peri-operative period, (ii) the use of bio-absorbable materials and Tightrope and (iii) evidence is emerging not to remove syndesmotic screws unless symptomatic.

AREAS OF TIMELY FOR DEVELOPMENT RESEARCH

(i) A bio-absorbable material that can be used to fix the syndesmosis and allow early weight bearing, and (ii) there is a need for developing a surgical technique for adequately reducing the syndesmosis without the exposure to radiation.

The lambda sign: a new radiographic indicator of latent syndesmosis instability

BACKGROUND

Latent syndesmotic instability is a common cause of chronic ankle pain. The diagnosis is not readily apparent on static imaging as the fibula remains reduced. The hypothesis of this study was that a previously undescribed novel finding on coronal MRI (lambda sign) is an independent indicator of latent syndesmosis instability. We also report on the utility of classic radiographic and physical exam findings.

METHODS

A total of 23 patients with latent syndesmotic instability diagnosed via arthroscopy (group I) were compared to a cohort of 40 patients who were found to have a stable syndesmosis during arthroscopy for unrelated conditions (group II). A retrospective chart review was performed evaluating their clinical history, preoperative physical examination, and radiologic findings. The lambda sign is a high intensity signal seen on coronal MR imaging that resembles the Greek letter lambda.

RESULTS

All of the physical exam findings tested were statistically significant. Pain at the syndesmosis had the highest sensitivity (83%), while pain reproduced with the proximal squeeze test resulted in the highest specificity (89%). The external rotation stress test had the highest positive predictive value (75%). Of the radiographic examinations performed, only the lambda sign was found to have statistical significance with a sensitivity of 75% and a specificity of 63%. The presence of a lambda sign on the MRI of patients with physical exam findings suggestive of syndesmotic pain was highly sensitive (75%) and specific (85%).

CONCLUSION

The lambda sign noted on the coronal MRI was both sensitive and specific for injuries involving greater than 2 mm of diastasis on arthroscopic stress examination of the syndesmosis. While neither the lambda sign nor any other finding on physical or radiographic examination represented an independent predictor of syndesmotic instability, the presence of a lambda sign in concert with positive physical exam findings might help health care providers determine which patients might benefit from operative intervention or referral.

LEVEL OF EVIDENCE

Level III, case control study.

Diagnosing chronic diastasis of the syndesmosis: a novel measurement using computed tomography

BACKGROUND

Chronic diastasis of the syndesmosis has been recognized as a cause of persistent pain and dysfunction after a rotational ankle injury. Recently, there has been an increased effort to define the use of computed tomography (CT) imaging in making this diagnosis; however, no clear consensus has been reached on the best way to assess the anatomical integrity of the syndesmosis. In this retrospective case series, we have evaluated the diagnostic capability of 2 novel CT-based measurements.

METHODS

Fourteen patients with symptomatic syndesmotic instability received a bilateral ankle CT scan. Two measurements were performed. The first measurement was the angle subtended by 2 lines drawn tangent to the anterior and posterior surfaces of the distal tibia and lateral malleolus 1 cm above the talar dome. The second measurement was the area bound by these lines, the lateral tibia and the medial aspect of the lateral malleolus. The injured and contralateral sides were compared using a Wilcoxon rank sum test with a significance set at P ≤ .05.

RESULTS

When comparing the injured to the contralateral ankle, we found a significant decrease in the angular measurement of the syndesmosis (63.4 ± 6.1 degrees vs 68.4 ± 6.6 degrees; P = .018) and a significant increase in the area measurement (1.71 ± 0.44 cm(2) vs 1.21 ± 0.25 cm(2); P = .00003). Eleven of 14 patients had a smaller angular measurement, and all 14 had a larger area measurement in the injured ankle. All patients were confirmed to have instability via manual testing intraoperatively.

CONCLUSIONS

This study suggests that a comparison of angular and area measurements will help identify a diastasis of the syndesmosis in patients with persistent pain after a rotational ankle fracture. These measurements are straightforward to perform and rely on landmarks that are easy to identify.

LEVEL OF EVIDENCE

Level IV, diagnostic.

Injuries to the ankle syndesmosis

➤ Despite being common, syndesmotic injuries are challenging to diagnose and treat.➤ Anatomic reduction of the ankle syndesmosis is critical for good clinical outcomes.➤ Intraoperative three-dimensional radiography and direct syndesmotic visualization can improve rates of anatomic reduction.➤ The so-called gold-standard syndesmotic screw fixation is being brought increasingly into question as new fixation techniques emerge.➤ Syndesmotic screw removal remains controversial, but may allow spontaneous correction of malreductions.

High-energy transsyndesmotic ankle fracture dislocation--the "Logsplitter" injury

OBJECTIVES

To describe and investigate the injury pattern and outcomes of high-energy transsyndesmotic ankle fracture dislocations, or "Logsplitter" injuries, in which the talus is axially wedged into the tibiofibular joint.

DESIGN

Prospective Cohort Study.

SETTING

Level 1 trauma center.

PATIENTS

Prospective evaluation of 23 high-energy transsyndesmotic ankle fracture dislocations (OTA 44-B).

INTERVENTION

Operative fixation.

MAIN OUTCOME MEASUREMENTS

Radiographs, clinical examination, American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale, Short Musculoskeletal Function Assessment.

RESULTS

Fracture characteristics included 52% open fractures (all medial) and syndesmotic widening of 30.7 ± 11.9 mm. The tibial plafond was involved in 11 (48%) of 23 injuries, with 5 (22%) Chaput, 5 (22%) posterior malleolar fragments, and 6 (26%) with articular impaction. A fibula fracture occurred in all but 1 patient, on average 64.2 ± 40.0 mm above the distal tip. All patients had fixation of their fibular and medial malleolar fractures, 21 of 23 patients had syndesmotic screws, and 8 of 23 had tibial plafond fixation. Anatomic alignment (within <= 2 mm) was obtained in 21 (87%) of 23 injuries. Mean follow-up was 20.6 ± 6.2 months. Sixteen (70%) of 23 patients had radiographic evidence of posttraumatic ankle arthritis. Dorsiflexion and plantarflexion at final follow-up were 6.9 ± 9.6 and 35.6 ± 12.1 degrees, respectively. Complications included a 17% infection and 17% nonunion rate. Average American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale score was 67.0 ± 26.8, whereas Short Musculoskeletal Function Assessment Dysfunction index was 32.9 ± 28.6 and Bother index 34.5 ± 29.5.

CONCLUSIONS

Transsyndesmotic ankle fracture dislocations, or "Logsplitter" injuries, represent an exceptional pattern of high-energy fractures with significant syndesmotic disruption, potential soft tissue compromise, and possible associated plafond injuries. Careful attention to radiographic findings can identify unique fracture characteristics relative to operative decision-making. Outcomes are comparable to those of high-energy pilon fractures, thereby providing the treating surgeon with prognostic information.

Syndesmosis injuries of the ankle

Ankle syndesmosis injuries are relatively frequent in sports, especially skiing, ice hockey, and soccer, accounting for 1 %-18 % of all ankle sprains. The evolution is unpredictable: When missed, repeated episodes of ankle instability may predispose to early degenerative changes, and frank osteoarthritis may ensue. Diagnosis is clinical and radiological, but arthroscopy may provide a definitive response, allowing one to address secondary injuries to bone and cartilage. Obvious diastasis needs to be reduced and fixed operatively, whereas less severe injuries are controversial. Nonoperative treatment may be beneficial, but it entails long rehabilitation. In professional athletes, more aggressive surgical treatment is warranted.