Anatomy of the distal tibiofibular syndesmosis in adults: a pictorial essay with a multimodality approach

Epidemiology of Foot and Ankle Injuries in National Collegiate Athletic Association Men's and Women's Ice Hockey

Background:

Ice hockey is a high-speed contact sport in which athletes are prone to many different injuries. While past studies have examined overall injury rates in ice hockey, foot and ankle injuries among collegiate ice hockey players have yet to be analyzed.

Purpose/Hypothesis:

The purpose of this study was to elucidate the epidemiology of foot and ankle injuries among collegiate ice hockey players utilizing data from the National Collegiate Athletic Association (NCAA) Injury Surveillance Program. We hypothesized that male ice hockey players would sustain more injuries compared with female ice hockey players and that the injuries sustained would be more severe.

Study Design:

Descriptive epidemiology study.

Methods:

Data on all foot and ankle injuries sustained during the academic years 2004 through 2014 were obtained from the NCAA Injury Surveillance Program. Injury rates, rate ratios (RRs), and injury proportion ratios were reported with 95% CIs.

Results:

Over the study period, the overall rate of foot and ankle injuries for men was higher than that for women (413 vs 103 injuries, respectively; RR, 4.01 [95% CI, 3.23-4.97]). Injury rates were highest during the regular season for both men (358 injuries; RR, 64.78 [95% CI, 58.07-71.49]) and women (89 injuries; RR, 38.37 [95% CI, 30.40-46.35]) compared with the preseason or postseason. The most common injury in men was a foot and/or toe contusion (22.5%), while women most commonly sustained a low ankle sprain (31.1%). For men, foot and/or toe contusions accounted for the most non–time loss (≤24 hours ) and moderate time-loss (2-13 days) injuries, while high ankle sprains accounted for the most severe time-loss (≥14 days) injuries. For women, foot and/or toe contusions accounted for the most non–time loss injuries, low ankle sprains accounted for the most moderate time-loss injuries, and high ankle sprains accounted for the most severe time-loss injuries.

Conclusion:

Foot and ankle injuries were frequent among collegiate ice hockey players during the period studied. For men, contusions were the most commonly diagnosed injury, although high ankle sprains resulted in the most significant time lost. For women, low ankle sprains were the most common and resulted in the most moderate time lost. These findings may direct future injury prevention and guide improvements in ice skate design.

Titanium cable isotonic annular fixation system for the treatment of distal tibiofibular syndesmosis injury

Distal tibiofibular syndesmosis injury (DTS) occurs frequently with ankle sprains. Current treatments pose several limitations including causing soft tissue irritation, bringing damage to fixation secondary to weight-bearing, and requiring follow-up surgeries. Here, we investigated the clinical effects of a new technique, titanium cable isotonic annular fixation, for the treatment of DTS injury. From January 2015 to June 2017, 36 patients with ankle fractures and DTS injuries had their fractures repaired with the titanium cable isotonic annular fixation system. Recovery was scored by the AOFAS ankle function score system. We also assessed the differences in ankle motion between healthy and operative joints, and recorded the complications. All patients recovered from surgery without any serious complications. We followed all the cases for 18-25 months with an average follow-up of 21.26±3.23 months. 12 months after the operation, X-ray images showed that the titanium cables were fixed in the correct position without any fracture or loosening. Additionally, no degeneration or traumatic arthritis was observed in the ankle joint. There were no incision or bone mineral density changes between the titanium fix and tibiofibular bones. Nearly all patients recovered well except for three who developed inflammation and infection. However, these three patients recovered following 1 week of intravenous antibiotics and local radiofrequency physiotherapy. According to the AOFAS scoring system, all patients achieved satisfactory recovery 12 months post operation. Our titanium cable isotonic annular fixation system has both the advantages of elastic and rigid fixations. It can restore isotonic strength of the distal tibiofibular joint, and its biomechanical performance approaches normal physiological function. After the operation, patients tolerated weight-bearing exercise and recovered joint mobility. Finally, there is no need to remove the distal tibiofibular implant after 12 weeks. Overall, it is a highly effective surgical method to treat DTS injury.

The effects of weight bearing on the distal tibiofibular syndesmosis: A study comparing weight bearing-CT with conventional CT

BACKGROUND

Syndesmotic injures are common and weight bearing imaging studies are often advocated to assess disruption. Although studies have examined the anatomical relationship between the fibula and incisura, the effect of weight-bearing on the syndesmosis has not been well reported. We characterise the changes which occur at the syndesmosis during weight-bearing.

METHODS

In this retrospective review we analysed the position of the fibula at the syndesmosis in a cohort of patients who underwent both non-weight-bearing and weight-bearing CT scans. The relative position of the fibula to the incisura was analysed to determine translation and rotation in the axial plane.

RESULTS

26 patients were included. Comparison of measurements revealed statistically significant differences between groups which indicated that on weight-bearing the fibula translated laterally and posteriorly, and rotated externally with respect to the incisura.

CONCLUSIONS

This is the first study to measure the differences in position of the syndesmosis during weight-bearing in a population of patients that have undergone both weight bearing and non weight bearing CT. Our study confirms that weight-bearing results in lateral and posterior translation, and external rotation of the fibula in relation to the incisura and our findings should help in future studies looking at the effect of weight bearing on syndesmotic pathology.

[Injuries of ligaments and tendons of foot and ankle : What every radiologist should know]

Injuries of the ligaments and tendons of the ankle and foot are among the most common musculoskeletal injuries. A correct and precise description of the pathology and possible accompanying injuries is essential for treatment planning by trauma and orthopedic surgeons. While X‑ray is used to exclude fractures, ultrasound is a very useful tool to assess the ligaments and tendons. For the radiologist, magnetic resonance imaging (MRI) is invaluable regarding the correct assessment of (partial) ruptures, as well as for evaluating accompanying injuries. The aim of the present overview is to provide the most relevant facts for radiologists regarding injuries of ligaments and tendons of the ankle and foot. A description of expected MRI findings and possible pitfalls are presented. For each ligament complex or tendon, we review the anatomy, followed by relevant facts on biomechanics and typical findings in case of injury. The lateral and medial ligament complex, syndesmosis, spring ligament complex, and the Lisfranc ligament are shown in detail. The Achilles tendon and the peroneal tendons are also discussed.

Morphological features of the inferior fascicle of the anterior inferior tibiofibular ligament

In this study, the inferior fascicle of the anterior inferior tibiofibular ligament (AITFL) was classified to provide basic information to help elucidate the mechanism of ankle joint anterolateral impingement, and the morphological features of each type were compared for the purpose of clarification. This investigation examined 100 feet from 52 cadavers. The AITFL was classified into four types according to the presence or absence of the inferior fascicle and the positional relationship between the AITFL and the inferior fascicle of the AITFL. The morphological features of the AITFL that were measured included the fibre bundle length, fibre bundle width, fibre bundle angle, and the distance between the joint levels. A distinct, independent inferior fascicle of the AITFL was identified in 15 feet (15%). There were no significant differences in the morphological features based on differences in the AITFL classification. Therefore, these findings suggest that the presence or absence of the inferior fascicle and the difference in the positional relationship between the AITFL and the inferior fascicle of the AITFL are less likely to be involved in impingement during ankle dorsiflexion.

In Vivo CT Analysis of Physiological Fibular Motion at the Level of the Ankle Syndesmosis During Plantigrade Weightbearing

Background. It is clear that motion at the syndesmosis occurs due to ranging of the ankle joint, but the influence of weightbearing with the foot in the plantigrade position is unclear. In vivo computed tomographic (CT) evaluation of the syndesmosis has not been previously described. The purpose of this study is to quantify physiological fibular motion at the level of the ankle syndesmosis in both weightbearing and nonweightbearing conditions with the foot in the plantigrade position. Methods. CT images were obtained from 9 normal healthy subjects using a weightbearing CT imaging system. The subjects were positioned in a nonweightbearing and weightbearing state with their foot in the plantigrade position. Fibular translation and rotation were measured from the axial CT images using previously validated techniques. Results. Both the average lateral and anteroposterior translation of the fibula between weightbearing and nonweightbearing states was minimal (0.3 mm and 0.2 mm, respectively). The largest difference in translation observed in either direction was 0.9 mm. An average of 0.5° was found for rotational differences of the fibula between weightbearing and nonweightbearing. Neither of the translational and rotational parameters reached statistical significance. Conclusion. In vivo CT analysis of the distal tibiofibular joint with an intact syndesmosis did not reveal statistically significant physiological motion between weightbearing and nonweightbearing conditions with the foot in plantigrade position. Our findings suggest that weightbearing accounts for little motion at the syndesmosis and supports further investigation into the role of early protected weightbearing after syndesmosis fixation. Levels of Evidence: Level III: Case-control study.

Influence of ankle joint position on angles and distances of the ankle mortise using intraoperative cone beam CT: A cadaveric study

BACKGROUND

The precise anatomical reduction of the ankle mortise is crucial for the clinical outcome in unstable syndesmotic injuries. Intraoperative cone beam computed tomography (CT), in addition to two-dimensional fluoroscopy, provides detailed information about the reduction and implant placement. The aim of this study was to analyze the influence of the joint position on the fibula position in the incisural notch and to determine the inter- and intraindividual anatomical differences in the intact ankle joints.

METHODS

A total of 20 fresh-frozen lower legs disarticulated in the knee joint of 10 individuals were included. The measurements were performed using a cone beam CT. The distances and angles were measured in the standard imaging planes. The mean values of distances and angles were compared during the different joint positions: 10° dorsiflexion, 0° neutral position and 20° plantar flexion.

RESULTS

The influence of the joint position was on average as follows: The anterior tibiofibular distance was 3.68 mm in 10° dorsiflexion, 3.66 mm (0° neutral position) and 3.59 mm (20° plantar flexion). The posterior tibiofibular distance measured 7.82mm, 7.76mm and 7.82mm. The rotation of the fibula measured ten millimeters proximal the joint line was 1.2°, 1.3° and 1.05°. The fibular rotation determined 4mm was 9.3°, 9.4° and 9.4°. On average, the following intraindividual variations were observed: superior tibiotalar clear space of 0.27mm and 0.15mm medial; and anterior tibiofibular distance of 0.42mm, 0.38mm posterior and 0.24mm in the incisural notch. The proximal angle of the fibular rotation was 0.2° and distal 0.4°. The interindividual variations of the angles and distances exceeded the intraindividual values partly by 3 to 4 fold.

CONCLUSIONS

Within the scope of this study neither the tibiofibular distance, nor the tibiofibular angle changed significantly through the different joint positions. The intraindividual differences were little while the interindividual variations of the parameters were distinctive.

Tibiofibular syndesmosis in asymptomatic ankles: initial kinematic analysis using four-dimensional CT

AIM

To evaluate the reliability of ankle syndesmotic measurements and their changes during active motion using four-dimensional computed tomography (4DCT) examination in asymptomatic ankles.

MATERIALS AND METHODS

4DCT was performed on both ankles of patients with signs and symptoms of unilateral ankle instability. Ankles from the asymptomatic side of 10 consecutive patients were included in this analysis. Five ankle syndesmotic measurements were adopted from the available literature and performed by two fellowship-trained foot and ankle surgeons: (1) syndesmotic anterior distance (SAD); (2) syndesmotic posterior distance (SPD); (3) syndesmotic translation (ST); (4) syndesmotic tibiofibular angle (STFA); and (5) ankle tibiofibular angle (ATFA). A Monte Carlo simulation was also performed to obtain exact p-values with 99% confidence intervals.

RESULTS

Excellent interobserver reliability was observed among the two readers for four out of five measurements (intra-class correlation coefficients [ICC]: 0.767-0.995, p<0.001-0.020). The ICC values for SAD were not statistically significant (ICC=0.548 and 0.569 for dorsi and plantarflexion respectively, p=0.1). Among the five measurements, only ST measurements had significant changes during active motion (median [interquartile range] for change: -0.70 mm [-1.6-0.10]; p=0.012). Of the above measurements, only the ST measurements demonstrated a negative linear association with the tibiocalcaneal angle during active motion (beta=-2.5, p=0.04).

CONCLUSIONS

Reliable quantitative kinematic assessment of ankle syndesmosis can be performed using 4DCT examination. Syndesmotic measurements remain unchanged during ankle motion except for the syndesmotic translation, which tends to decrease during plantar flexion.

A standardised computed tomography measurement method for distal fibular rotation

PURPOSE

The aim of the study is to identify an ideal location to measure fibular rotation in the ankle joint using axial computed tomography (CT) scans. Another objective was to detect the average fibular rotation in the uninjured ankle joint in a large cohort.

METHODS

Standardised axial CT with coronal/sagittal reconstructions was performed in healthy ankle joints. Three investigators performed the measurements. In the axial view, each investigator appointed the ideal location to measure the angle of fibular rotation with the use of reference lines either 4, 6, 8 or 10 mm distal from the talar joint line. Inter- and intraobserver reliability, as well as the intraclass correlation coefficient, were determined.

RESULTS

CT scans of one hundred individuals-78 males and 22 females-were analysed. The most common locations for measuring the fibular rotation were in 31% of cases 4 mm and in 51% of cases 6 mm distal the talar joint line. The external rotation of the fibula averaged 8.42° ± 4.86° (range 0°-26°). The intraclass coefficient correlations (ICC) for interrater and intrarater reliability were 0.75.

CONCLUSIONS

The results of the study demonstrate a reproducible location to measure the fibular rotation in the ankle joint. The most convenient location to measure fibular rotation with a high reliability was 6 mm distal to the talar joint line.

Defining reference values for the normal tibiofibular syndesmosis in adults using weight-bearing CT

Aims

Cone beam CT allows cross-sectional imaging of the tibiofibular syndesmosis while the patient bears weight. This may facilitate more accurate and reliable investigation of injuries to, and reconstruction of, the syndesmosis but normal ranges of measurements are required first. The purpose of this study was to establish: 1) the normal reference measurements of the syndesmosis; 2) if side-to-side variations exist in syndesmotic anatomy; 3) if age affects syndesmotic anatomy; and 4) if the syndesmotic anatomy differs between male and female patients in weight-bearing cone beam CT views.

Patients and Methods

A retrospective analysis was undertaken of 50 male and 50 female patients (200 feet) aged 18 years or more, who underwent bilateral, simultaneous imaging of their lower legs while standing in an upright, weight-bearing position in a pedCAT machine between June 2013 and July 2017. At the time of imaging, the mean age of male patients was 47.1 years (18 to 72) and the mean age of female patients was 57.8 years (18 to 83). We employed a previously described technique to obtain six lengths and one angle, as well as calculating three further measurements, to provide information on the relationship between the fibula and tibia with respect to translation and rotation.

Results

The upper limit of lateral translation in un-injured patients was 5.27 mm, so values higher than this may be indicative of syndesmotic injury. Anteroposterior translation lay within the ranges 0.31 mm to 2.59 mm, and -1.48 mm to 3.44 mm, respectively. There was no difference between right and left legs. Increasing age was associated with a reduction in lateral translation. The fibulae of men were significantly more laterally translated but data were inconsistent for rotation and anteroposterior translation.

Conclusion

We have established normal ranges for measurements in cross-sectional syndesmotic anatomy during weight-bearing and also established that no differences exist between right and left legs in patients without syndesmotic injury. Age and gender do, however, affect the anatomy of the syndesmosis, which should be taken into account at time of assessment. Cite this article: Bone Joint J 2019;101-B:348–352.

Arthroscopic Grading of Injuries of the Inferior Tibiofibular Syndesmosis

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

Anatomy of the tibial incisura as a risk factor for syndesmotic injury

BACKGROUND

The study aims at comparing the bony anatomy of the syndesmosis in patients who sustained a high fibular fracture with syndesmosis disruption and that of the non-injured population. We hypothesised that there are certain anatomical features making the syndesmosis susceptible to injury.

METHODS

The CT examinations of 75 patients who sustained a high fibular fracture with syndesmosis disruption and control group of 75 patients with unrelated foot problems were compared. The depth, fibular engagement and rotational orientation of the tibial incisura were analyzed.

RESULTS

With the median values of the control group as cutoff there were 71% shallow, 71% disengaged and 77% retroverted syndesmoses in the injury group. The differences between the groups were statistically significant for every measure (P<.002 to P>.0001).

CONCLUSIONS

Patients with a shallow, disengaged and retroverted bony configuration of the syndesmosis are overrepresented among patients with syndesmosis disruption.

Templating of Syndesmotic Ankle Lesions by Use of 3D Analysis in Weightbearing and Nonweightbearing CT

BACKGROUND:

Diagnosis and operative treatment of syndesmotic ankle injuries remain challenging due to the limitations of 2-dimensional imaging. The aim of this study was therefore to develop a reproducible method to quantify the displacement of a syndesmotic lesion based on 3-dimensional computed imaging techniques.

METHODS:

Eighteen patients with a unilateral syndesmotic lesion were included. Bilateral imaging was performed with weightbearing cone-beam computed tomography (CT) in case of a high ankle sprain (n = 12) and by nonweightbearing CT in case of a fracture-associated syndesmotic lesion (n = 6). The healthy ankle was used as a template after being mirrored and superimposed on the contralateral ankle. The following anatomical landmarks of the distal fibula were computed: the most lateral aspect of the lateral malleolus and the anterior and posterior tubercle. The change in position of these landmarks relative to the stationary, healthy fibula was used to quantify the syndesmotic lesion. A control group of 7 studies was used.

RESULTS:

The main clinical relevant findings demonstrated a statistically significant difference between the mean mediolateral diastasis of both the sprained (mean [SD], 1.6 [1.0] mm) and the fracture group (mean [SD], 1.7 [0.6] mm) compared to the control group ( P < .001). The mean external rotation was statistically different when comparing the sprained (mean [SD], 4.7 [2.7] degrees) and the fracture group (mean [SD], 7.0 [7.1] degrees) to the control group ( P < .05).

CONCLUSION:

This study evaluated an effective method for quantifying a unilateral syndesmotic lesion of the ankle. Applications in clinical practice could improve diagnostic accuracy and potentially aid in preoperative planning by determining which correction needs to be achieved to have the fibula correctly reduced in the syndesmosis.

LEVEL OF EVIDENCE:

Level III, retrospective comparative study.

Posterolateral Spiral-Shaped One Third Tubular Plate Stabilization for a Long Spiral Fracture of the Lateral Malleolus

We present surgical stabilization of a long spiral fibular fracture using a contoured plate, which allows for better fixation of the fracture compared with standard plating. We believe this technique modification provides satisfactory compression and better anatomic orientation to the fibula to facilitate closed fixation.

Variations in the Anatomic Morphology of the Lateral Distal Tibia: Surgical Implications for Distal Tibial Allograft Glenoid Reconstruction

BACKGROUND

Distal tibial allograft glenoid augmentation has been introduced as a viable treatment approach for glenoid bone loss in conjunction with shoulder instability. No previous study, however, has assessed the morphologic variation of the distal tibia at the incisura as it relates to graft dimensions for glenoid augmentation. Increased concavity at the lateral distal tibia necessitates removal of the lateral cortex to obtain a flat surface, which may have implications for the strength of surgical fixation.

PURPOSE

To assess the morphologic variation of the distal tibia at the incisura as it relates to graft dimensions for glenoid augmentation.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Magnetic resonance images of the ankle were reviewed for morphology assessment of the appearance and depth of the distal tibia. A classification system was created reflecting the suitability for glenoid augmentation. Type A tibias contained a flat contour of the lateral tibia at the articular surface, indicative of an ideal graft. Type B tibias had slight concavity with a central depth <5 mm and were deemed acceptable grafts. Type C tibias had deep concavity with a central depth >5 mm and were deemed unacceptable. Statistical analysis was performed via univariate analyses to compare patient demographics against acceptable morphology for glenoid augmentation.

RESULTS

Eighty-five study patients met inclusion criteria (53 male, 32 female; mean age ± SD, 35.1 ± 10.3 years). Overall, 12 patients (14.1%) demonstrated type A morphology, with 61 patients (71.8%) having type B morphology for a total of 85.9% of acceptable grafts for glenoid augmentation. The interrater reliability was moderate to strong between observers (kappa value = 0.841). On univariate analysis, sex was the only variable significantly associated with an acceptable graft, with 100% of female patients having acceptable morphology, as compared with 77% of male patients ( P = .004).

CONCLUSION

Variable morphology of the distal tibia at the incisura was found: 14.1% of patients demonstrated an ideal morphology for glenoid augmentation; an additional 71.8% were deemed suitable for graft usage; and 14.1% of tibias had unacceptable morphology. Sex was a significant factor for predicting acceptable grafts.

CLINICAL RELEVANCE

This information will assist surgeons in accepting or rejecting grafts based on the epidemiology of the distal tibial morphology as it relates to glenoid augmentation.

In Vivo Three-Dimensional Analysis of Malunited Forearm Diaphyseal Fractures with Forearm Rotational Restriction

BACKGROUND

The aim of this study was to clarify the mechanisms of rotational restriction in malunited forearm diaphyseal fractures.

METHODS

We retrospectively analyzed the cases of 18 patients with malunited forearm diaphyseal fractures and rotational restriction. All patients underwent bilateral computed tomography (CT) of the forearm in maximum supination, pronation, and neutral positions. From these images, we created 3-dimensional (3-D) bone surface models. We quantified the 3-D deformities, identified instances of osseous impingement between the radius and the ulna during forearm rotation, calculated the path length of the central band (CB) of the interosseous membrane, and measured forearm range of motion.

RESULTS

Sixteen patients had extension deformity of the radius (the RE group) and 2 had flexion deformity (the RF group). In the RE group, extension deformity of the radius and valgus deformity of the ulna had significant negative correlation with pronation range of motion (R = -0.50, p = 0.046) and supination range of motion (R = -0.63, p = 0.027), respectively. Osseous impingement was mainly observed during pronation (15 of 16 patients). The CB path with the largest changes in length originated from the distal CB attachment area of the radius and ran toward the proximal area of the ulna (the transverse CB). The transverse CB significantly increased in length in supination compared with that in pronation (p < 0.001). Therefore, tightness of the transverse CB appeared to cause supination restriction in the RE group. In the RF group, osseous impingement caused supination restriction. The greatest increases in the transverse CB length were observed in pronation in the RF group, which appeared to cause pronation restriction.

CONCLUSIONS

In the RE group, pronation restriction was associated with osseous impingement that was due to extension deformity of the radius, and supination restriction was associated with CB tightness that was due to valgus deformity of the ulna. In the RF group, our results suggested that pronation restriction was caused by CB tightness and that supination restriction was caused by osseous impingement.

CLINICAL RELEVANCE

Three-dimensional corrective osteotomy for extension deformity of the radius in malunited forearm diaphyseal fractures would improve rotational restriction by relieving osseous impingement during pronation and CB tightness during supination.

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.

Ankle and midfoot ligaments: Ultrasound with anatomical correlation: A review

We present a detailed overview of anatomical and US features of ankle and midfoot ligaments based on our own dissections and cadaver studies as well as US imaging in cadavers and volunteers. The ligament anatomy about the ankle and midfoot is complex. Most ligaments are superficial and hence very well accessible for US. US technique to obtain optimal visualization however is difficult and requires a learning curve. We discuss US technique in detail for each individual ligament. We divided the ligaments in different groups: tibiofibular ligaments, Bassett's ligament, lateral collateral ligament complex (anterior talofibular ligament, calcaneofibular ligament, lateral talocalcaneal ligament, posterior talofibular ligament), medial collateral ligament complex, spring ligament, Chopart joint ligaments (bifurcate ligament, dorsal talonavicular ligament, lateral calcaneocuboid ligament, long and short plantar ligaments), Lisfranc ligaments, sinus tarsi ligaments.

Classification system of the tibiofibular syndesmosis blood supply and its clinical relevance

Due to the lack of anatomical studies concerning complexity of the tibiofibular syndesmosis blood supply, density of blood vessels with further organization of syndesmotic vascular variations is presented in clinically relevant classification system. The material for the study was obtained from cadaveric dissections. We dissected 50 human ankles observing different types of arterial blood supply. Our classification system is based on the vascular variations of the anterior aspect of tibiofibular syndesmosis and corresponds with vascular density. According to our study the mean vascular density of tibiofibular syndesmosis is relatively low (4.4%) and depends on the type of blood supply. The highest density was observed among ankles with complete vasculature and the lowest when lateral anterior malleolar artery was absent (5.8% vs. 3.5%, respectively). Awareness of various types of tibiofibular syndesmosis arterial blood supply is essential for orthopedic surgeons who operate in the ankle region and radiologists for the anatomic evaluation of this area. Knowledge about possible variations along with relatively low density of vessels may contribute to modification of treatment approach by the increase of the recommended time of syndesmotic screw stabilization in order to prevent healing complications.

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.

Imaging in syndesmotic injury: a systematic literature review

OBJECTIVES

To give a systematic overview of current diagnostic imaging options for assessment of the distal tibio-fibular syndesmosis.

MATERIALS AND METHODS

A systematic literature search across the following sources was performed: PubMed, ScienceDirect, Google Scholar, and SpringerLink. Forty-two articles were included and subdivided into three groups: group one consists of studies using conventional radiographs (22 articles), group two includes studies using computed tomography (CT) scans (15 articles), and group three comprises studies using magnet resonance imaging (MRI, 9 articles).The following data were extracted: imaging modality, measurement method, number of participants and ankles included, average age of participants, sensitivity, specificity, and accuracy of the measurement technique. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool was used to assess the methodological quality.

RESULTS

The three most common techniques used for assessment of the syndesmosis in conventional radiographs are the tibio-fibular clear space (TFCS), the tibio-fibular overlap (TFO), and the medial clear space (MCS). Regarding CT scans, the tibio-fibular width (axial images) was most commonly used. Most of the MRI studies used direct assessment of syndesmotic integrity. Overall, the included studies show low probability of bias and are applicable in daily practice.

CONCLUSIONS

Conventional radiographs cannot predict syndesmotic injuries reliably. CT scans outperform plain radiographs in detecting syndesmotic mal-reduction. Additionally, the syndesmotic interval can be assessed in greater detail by CT. MRI measurements achieve a sensitivity and specificity of nearly 100%; however, correlating MRI findings with patients' complaints is difficult, and utility with subtle syndesmotic instability needs further investigation. Overall, the methodological quality of these studies was satisfactory.

Comparing Different Surgical Techniques for Addressing the Posterior Malleolus in Supination External Rotation Ankle Fractures and the Need for Syndesmotic Screw Fixation

Trimalleolar ankle fractures are unstable injuries with possible syndesmotic disruption. Recent data have described inherent morbidity associated with screw fixation of the syndesmosis, including the potential for malreduction, hardware irritation, and post-traumatic arthritis. The posterior malleolus is an important soft tissue attachment for the posterior inferior syndesmosis ligament. We hypothesized that fixation of a sizable posterior malleolar (PM) fracture in supination external rotation type IV (SER IV) ankle fractures would act to stabilize the syndesmosis and minimize or eliminate the need for trans-syndesmotic fixation. A retrospective review of trimalleolar ankle fractures surgically treated from October 2006 to April of 2011 was performed. A total of 143 trimalleolar ankle fractures were identified, and 97 were classified as SER IV. Of the 97 patients, 74 (76.3%) had a sizable PM fragment. Syndesmotic fixation was required in 7 of 34 (20%) and 27 of 40 (68%), respectively, when the PM was fixed versus not fixed (p = .0002). When the PM was indirectly reduced using an anterior to posterior screw, 7 of 15 patients (46.7%) required syndesmotic fixation compared with none of 19 patients when the PM fragment was fixated with direct posterior lateral plate fixation (p = .0012). Fixation of the PM fracture in SER IV ankle fractures can restore syndesmotic stability and, thus, lower the rate of syndesmotic fixation. We found that fixation of a sizable PM fragment in SER IV or equivalent injuries through posterolateral plating can eliminate the need for syndesmotic screw fixation.

High incidence of screw penetration in the proximal and distal tibiofibular joints after intramedullary nailing of tibial fractures-A prospective cohort and mapping study

BACKGROUND

Intramedullary-nails (IMN) are the treatment of choice for most tibial shaft fractures due to their minimally-invasive nature and non-demanding surgical technique. However, a potential iatrogenic pitfall is intra-articular interlocking screw positioning within the proximal (PTFJ) and distal (DTFJ) tibiofibular joints that may go unrecognized.

OBJECTIVE

To evaluate the incidence of intra-articular screw penetration of the PTFJ and DTFJs after interlocking of IMN for tibial fractures.

INTERVENTION

Reamed IMN using modern techniques, including proximal interlocking via standard aiming jig and distal interlocking either freehand or using SureShot^®.

METHODS

Prospective series of 165 consecutive patients with a tibial shaft fracture managed with an IMN. Diagnosis and incidence of penetration of the PTFJ and DTFJ was assessed on protocolled low-dose postoperative CT-scans (standardized clinical practice for assessing rotational alignment). The degree of penetration of the TFJ's was graded as: Grade 1-slight breach of the tibial cortex; Grade 2-clear penetration of the tibial cortex with intra-articular screw tip; and Grade 3-penetration of both tibial- and fibular cortices with screw tip in fibula.

RESULTS

Of the 165 tibial shaft fractures, using the AO/OTA classification, 69% were simple, 16% wedge and 15% complex fractures. Following IMN 42% of patients had intra-articular screw penetration of their PTFJ whilst 39% had penetration of their DTFJ. 66% of patients had penetration of either one- or both of their TFJs. The grading of PTFJ violation was distributed as follows: Grade 1 in 24 patients; Grade 2 in 26 patients and Grade 3 in 19 patients. DTFJ violation was graded as: Grade 1 in 21 patients; 40 patients had Grade 2 violation; and four patients had a Grade 3 penetration.

CONCLUSIONS

This diagnostic imaging study reports a high rate of intra-articular screw penetration of the PTFJ and DTFJ after interlocking of IMN for tibia shaft fractures. A prospective cohort study is underway to evaluate its clinical significance. Changes to enable alteration in forced angle of interlocking screw trajectory and avoidance of the anteromedial to posterolateral locking screw may reduce the incidence of TJF violation.

LEVEL OF EVIDENCE

Level II - Diagnostic Imaging Study.

Stability of the Syndesmosis After Posterior Malleolar Fracture Fixation

BACKGROUND

We sought to define the rate of syndesmotic instability after anatomic reduction of the posterior malleolus when posterior stabilization of a trimalleolar or trimalleolar equivalent ankle fracture was chosen vs when a supine position and initially conservative management of the posterior elements was chosen.

METHODS

The types of syndesmotic and posterior malleolar fixation used to treat adult patients with ankle fractures involving the posterior malleolus at our level I trauma center were retrospectively assessed (N = 198). Specifically, both bimalleolar and trimalleolar fractures were included. Exclusion criteria included pilon fractures, trimalleolar fractures with Chaput fragments, and neurologic injury. Demographics, fracture classification, initial operative position, medial clear space, and posterior malleolar fragment size were recorded for each fracture.

RESULTS

In total, 151 patients (76.3%) were initially positioned supine, 27.2% of whom had syndesmotic instability requiring operative stabilization. Almost 25% of supine patients also underwent posterior malleolar stabilization for posterior instability. Overall, 73 (48.3%) patients who were initially treated in the supine position needed some form of additional stabilization. Forty-seven patients (23.7%) were initially positioned prone. Syndesmotic stability was restored in 97.9% of these patients. This 2.1% rate of instability vastly differs from the 13-fold higher syndesmotic instability rate observed in the supine group ( P < .001).

CONCLUSION

Our data demonstrate that the rate of syndesmotic instability was reduced in trimalleolar and trimalleolar equivalent fractures when prone positioning and direct fixation of the posterior malleolus were first performed. Using traditional preoperative estimates of posterior stability to determine the need for posterior malleolar fixation may be inadequate since almost a quarter of patients treated supine received posterior stabilization.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

Epidemiology and return to play following isolated syndesmotic injuries of the ankle: a prospective cohort study of 3677 male professional footballers in the UEFA Elite Club Injury Study

Aim

To determine the epidemiology of isolated syndesmotic injuries in professional football players.

Methods

Data from 15 consecutive seasons of European professional football between 2001 and 2016 contributed to the dataset of this study. Match play and training data from a total of 3677 players from 61 teams across 17 countries have been included. Team medical staff recorded player exposure and time loss injuries. Injury incidence was defined as the number of injuries per 1000 player-hours. Injury burden was defined as number of days absence per 1000 player-hours. Seasonal trends for isolated syndesmotic injury incidence, isolated syndesmotic injury proportion of ankle ligament injuries and isolated syndesmotic injury burden were analysed via linear regression.

Results

The isolated syndesmotic injury incidence was 0.05 injuries per 1000 hours of exposure (95% CI 0.04 to 0.06) or one injury per team every three seasons. The injury incidence during match play was 13 times higher compared with during training, 0.21 (95% CI 0.16 to 0.26) and 0.02 (95% CI 0.01 to 0.02), respectively. Out of the 1320 ankle ligament injuries registered during the 15 seasons, 94 (7%) were diagnosed as isolated syndesmotic injuries. An annual increase in injury incidence was observed (R2=0.495, b=0.003, 95% CI 0.001 to 0.004, P=0.003). However, no significant annual change of injury burden was observed (R2=0.033, b=0.032, 95% CI −0.073 to 0.138, P=0.520). Seventy-four per cent of the injuries were contact related, and the mean (±SD) absence following an isolated syndesmotic injury was 39 (±28) days.

Conclusions

The incidence of isolated syndesmotic injuries in elite professional European football annually increased between 2001 and 2016.

A New Intraoperative Syndesmosis Instability Classification System: Utility and Medium-term Results in Closed Displaced Ankle Fractures

OBJECTIVE

To investigate the utility and medium-term results of a new intra-operative classification system for distal tibiofibular syndesmosis injury in ankle fractures.

METHODS

Between January 2010 and January 2015, 116 patients diagnosed with displaced closed Weber B and C ankle fractures were treated in our department. The etiology of injury was 56 cases of fall-sprain, 36 of traffic injury, 14 of fall from a height, and 10 of multiple injuries. After fixation of the fibular fracture, we classify syndesmosis stability as either normal or one of three grades of instability using the fibular hook traction test. This determined further fixation selection and final syndesmosis treatment.

RESULTS

Of 116 cases, 82 (71%) demonstrated a tibiofibular syndesmosis injury and 52 (45%) were unstable. Twenty-six cases were type I injuries (<4 mm displacement), 41% cases were type II injuries (4-7 mm displacement), and 3% of cases were type III injuries (>7 mm displacement). Types II and III are defined as unstable and require stabilization. Type III injuries have multiplanar instability and require two screws at the syndesmosis. Weber C fractures demonstrate significantly greater degrees of instability than Weber B fractures (χ² = 15.50, P = 0.0014). All patients were followed up for 12-24 months, with no cases of non-union or broken screws. Good and excellent results were achieved in 93% of cases (according to the American Orthopaedic Foot and Ankle Society scoring system).

CONCLUSION

The syndesmosis instability classification system provides a rational and efficient basis for managing syndesmosis instability. Our results from application of the algorithm justify its further evaluation in the treatment of patients with closed displaced Weber B and C ankle fractures.

Distal Tibiofibular Syndesmosis: Anatomy, Biomechanics, Injury and Management

A stable and precise articulation of the distal tibiofibular syndesmosis is essential for normal motion of the ankle joint. Injury to the syndesmosis occurs through rupture or bony avulsion of the syndesmotic ligament complex. External rotation of the talus has been identified as the major mechanism of syndesmotic injury. None of the syndesmotic stress tests was sensitive or specific; therefore the diagnosis of syndesmotic injury should not be made based on the medical history and physical examination alone. With the improvement in ankle arthroscopic technique, it can be used as a diagnostic and therapeutic tool in the management of distal tibiofibular syndesmosis injury.

The Epidemiology of High Ankle Sprains in National Collegiate Athletic Association Sports

BACKGROUND

Ankle sprains are among the most common injuries experienced by collegiate athletes. The type of ankle sprain is rarely differentiated in epidemiological studies. This differentiation is necessary, as each ankle sprain type has a unique injury mechanism and recovery period. High ankle sprains commonly result in long recovery periods. Thus, a further examination of the epidemiology of high ankle sprains is warranted.

PURPOSE

To describe the epidemiology of high ankle sprains in National Collegiate Athletic Association (NCAA) sports during the 2009/2010-2014/2015 academic years.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

NCAA Injury Surveillance Program high ankle sprain data and athlete-exposures (AEs) from 25 sports were evaluated. Certified athletic trainers recorded sport-related injury, event, and AE data during team-sanctioned events. High ankle sprain injury rates per 10,000 AEs were calculated. Percentage distributions were calculated for the amount of time lost from sport and percentage of recurrent injuries. Injury rate ratios (RRs) and 95% CIs compared injury rates by event type, participation restriction time, and sex. 95% CIs not containing 1.00 were considered statistically significant.

RESULTS

The overall high ankle sprain injury rate was 1.00 per 10,000 AEs. Overall, 56.7% of high ankle sprain injuries occurred during competitions, and 9.8% of high ankle sprain injuries were recurrent. Men's football (2.42/10,000 AEs), wrestling (2.11/10,000 AEs), and ice hockey (1.19/10,000 AEs) had the highest high ankle sprain injury rates. In sex-comparable sports, men had higher injury rates (RR, 1.77; 95% CI, 1.28-2.44). Player contact was the most common injury mechanism (60.4%), and 69.0% of injuries resulted in ≥1 day of participation restriction, with 47.1% resulting in ≥7 days of participation restriction and 15.8% resulting in >21 days of participation restriction.

CONCLUSION

High ankle sprains resulted in significant participation restriction time from sport participation. The majority of high ankle sprain injuries resulted from player contact and were observed in contact/collision sports. The large proportion of high ankle sprains resulting from player contact, specifically in male contact sports, is worthy of further investigation.

CLINICAL RELEVANCE

The enhanced understanding of the epidemiology of high ankle sprains provided in our study will aid clinicians in developing targeted injury prevention strategies to mitigate the negative consequences of these injuries.

Novel anatomical reconstruction of distal tibiofibular ligaments restores syndesmotic biomechanics

PURPOSE

To date, there is a paucity of literature on syndesmotic reconstruction techniques that restore both anatomic stability and physiologic syndesmotic biomechanics. In this cadaveric study, (1) a novel syndesmotic reconstruction surgical technique using autogenous peroneus brevis tendon was described and (2) the biomechanical properties of the reconstruction was investigated.

METHODS

Ten fresh-frozen lower extremities were used in this study. Reconstruction of the anterior and posterior, as well as the interosseous tibiofibular ligaments was performed with a halved peroneus brevis tendon. Biomechanics were assessed using foot external rotation torque and ankle dorsiflexion axial loading tests, which were performed in (a) intact, (b) cut, (c) anatomically reconstructed syndesmotic ligaments, and (d) 3.5 mm tricortical syndesmotic screw fixation. Medial-lateral and anterior-posterior displacements of the distal fibula were recorded during foot external rotation and fibular axial displacement was recorded during ankle axial loading.

RESULTS

The fibula was displaced posteriorly and proximally with respect to the tibia in all specimens during external rotation and axial loading tests, respectively. Significant differences (p < 0.05) were found in distal fibular displacements between anatomically reconstructed ligaments and screw fixation. Tricortical syndesmotic screw fixation resulted in 59% of posterior fibular displacement when compared to intact ligaments. No significant differences (n.s.) in distal fibular displacement were demonstrated between intact ligaments and anatomically reconstructed ligaments.

CONCLUSION

Anatomical reconstruction of the distal tibiofibular ligaments with the peroneus brevis tendon provides stability and recreates the biomechanical properties of an intact syndesmosis. This new surgical technique may be a viable alternative for the treatment of syndesmotic injuries.

LEVEL OF EVIDENCE

V.

Posterior ankle labral changes at MRI: A preliminary study

INTRODUCTION

The transverse ligament in the ankle joint has been described as a labrum-like structure in a previous cadaveric study. The purpose of this study is to assess the spectrum of abnormal changes related to this structure on imaging/MRI, and correlate these findings with other ankle joint findings and patient symptoms.

METHOD

A retrospective observational review of 172 ankle MRI scans was carried out independently by two fellowship trained musculoskeletal Radiologists. Correlation between abnormal labral changes, other ankle joint findings and patient symptomatology was performed.

RESULTS

Abnormal labral changes were seen in 26% of the MRI scans (n = 44/172) and included signal change, contour abnormality with heterogeneous signal change, linear fluid filled clefts, multidirectional fluid filled clefts, and a macerated labrum. There was a statistically significant association between abnormal labral changes and the presence of Stieda process/os trigonum (P = 0.001), talocrural joint osteoarthritis (P = 0.0003), paralabral cysts (P = 0.0001), imaging features of posterior impingement (P = 0.01), and both medial (P = 0.005) and lateral (P = 0.01) ankle ligament injuries. However, there was no statistically significant association between abnormal labral changes and patient symptoms.

CONCLUSION

The posterior ankle labrum can develop a spectrum of abnormal MRI appearances in patients with other ankle joint abnormalities. Although this study showed no correlation between patients' symptoms and posterior ankle labral changes, larger studies are needed to examine the biomechanical alterations that may arise from these labral changes.

Syndesmotic InternalBraceTM for anatomic distal tibiofibular ligament augmentation

Reconstruction of unstable syndesmotic injuries is not trivial, and there is no generally accepted treatment guidelines. Thus, there still remain considerable controversies regarding diagnosis, classification and treatment of syndesmotic injuries. Syndesmotic malreduction is the most common indication for early re-operation after ankle fracture surgery, and widening of the ankle mortise by only 1 mm decreases the contact area of the tibiotalar joint by 42%. Outcome of ankle fractures with syndesmosis injury is worse than without, even after surgical syndesmotic stabilization. This may be due to a high incidence of syndesmotic malreduction revealed by increasing postoperative computed tomography controls. Therefore, even open visualization of the syndesmosis during the reduction maneuver has been recommended. Thus, the most important clinical predictor of outcome is consistently reported as accuracy of anatomic reduction of the injured syndesmosis. In this context the TightRope^® system is reported to have advantages compared to classical syndesmotic screws. However, rotational instability of the distal fibula cannot be safely limited by use of 1 or even 2 TightRopes^®. Therefore, we developed a new syndesmotic InternalBrace^TM technique for improved anatomic distal tibiofibular ligament augmentation to protect healing of the injured native ligaments. The InternalBrace^TM technique was developed by Gordon Mackay from Scotland in 2012 using SwiveLocks^® for knotless aperture fixation of a FiberTape^® at the anatomic footprints of the augmented ligaments, and augmentation of the anterior talofibular ligament, the deltoid ligament, the spring ligament and the medial collateral ligaments of the knee have been published so far. According to the individual injury pattern, patients can either be treated by the new syndesmotic InternalBrace^TM technique alone as a single anterior stabilization, or in combination with one posteriorly directed TightRope^® as a double stabilization, or in combination with one TightRope^® and a posterolateral malleolar screw fixation as a triple stabilization. Moreover, the syndesmotic InternalBrace^TM technique is suitable for anatomic refixation of displaced bony avulsion fragments too small for screw fixation and for indirect reduction of small posterolateral tibial avulsion fragments by anatomic reduction of the anterior syndesmosis with an InternalBrace^TM after osteosynthesis of the distal fibula. In this paper, comprehensively illustrated clinical examples show that anatomic reconstruction with rotational stabilization of the syndesmosis can be realized by use of our new syndesmotic InternalBrace^TM technique. A clinical trial for evaluation of the functional outcomes has been started at our hospital.

Ankle syndesmosis repair and rehabilitation in professional rugby league players: a case series report

Background/aim

The distal tibiofibular joint is described as a syndesmosis. Traditionally, severe syndesmotic injuries with diastasis have been treated surgically with screw fixation. This case series details an ankle syndesmosis tightrope repair and an accelerated rehabilitation protocol that reduces the amount of time to return to professional rugby league in the UK. The aim of this study was to describe players’ journey from injury, through diagnosis to surgery, rehabilitation and return to participation, detailing time scales and methods used at each stage to highlight the change in current practice.

Methods

Players were identified via a single orthopaedic surgeon in the UK who specialises in ankle syndesmosis repair. Between January 2010 and September 2015, adult men playing full-time professional rugby league in the UK Super League with ankle syndesmosis injuries were identified.

Results

Eighteen players from six different clubs were included. The most common mechanism of injury was forced dorsiflexion/eversion. The average return to participation was 64 days (SD 17.2, range 38–108). This compares favourably to reports of between 120 and 180 days following screw fixation.

Conclusion

Ankle syndesmosis tightrope repair and an accelerated rehabilitation protocol is as safe as traditional methods. The accelerated rehabilitation protocol promotes early weight-bearing and has shown to expedite the return to sport for professional Rugby League players. It is possible to return to sport 2 months after a tightrope repair and accelerated rehabilitation, compared with 3–6 months post screw fixation. This is extremely encouraging for the professional sporting population.

An Anatomical Study on the Safe Placement of Orthopedic Hardware for Syndesmosis Fixation

Articular cartilage and bony contact at the distal tibiofibular cartilage contact zone (TFCCZ) is variable. The appropriate placement of syndesmotic hardware would benefit from a more accurate characterization of the proximal extent of the TFCCZ allowing surgeons to place hardware that simultaneously improves biomechanical stability and decreases the risk of iatrogenic cartilage damage. In addition, Ilizarov wire fixation through the distal fibula and tibia can pass through the syndesmosis recess. Anatomically defining the proximal extent of this recess can help decrease the risk of inadvertent capsular penetration. This study anatomically defines the TFCCZ and syndesmosis recess establishing a safe and biomechanically advantageous distance from the plafond for orthopedic fixation. This study measured the height of the TFCCZ and the syndesmotic recess in 3158 anatomical and cadaveric specimens. A TFCCZ was present in 59% of the Robert J. Terry Anatomical Collection specimens. Maximal height of the TFCCZ averaged 5.7±1.7 mm (99% confidence interval [CI], 5.6-5.8 mm) for anatomical specimens and 5.6±1.6 mm (99% CI, 4.6-6.5 mm) for cadaveric dissections. The maximum TFCCZ height was 11.71 mm. Maximal height of the syndesmotic recess averaged 12.8±2.1 mm for anatomical specimens and 13.7±2.7 mm for cadaveric specimens. The "3 cm rule" appears to be appropriate for fine wire fixation accounting for capsular distension that can be associated with injuries but not applicable for syndesmotic fixation. There is a less than 0.1% chance of encountering the TFCCZ cartilage at 10.9 mm above the plafond and a less than 0.01% chance at 12 mm above the plafond. [Orthopedics. 2017; 40(2):e329-e333.].

MRI Quantification of the Impact of Ankle Position on Syndesmosis Anatomy

BACKGROUND

Despite the common occurrence of syndesmotic injuries in ankle trauma, the distal tibiofibular relationship remains poorly understood. The aim of this study was to evaluate the anatomical impact of ankle sagittal positioning on the tibiofibular relationship in intact ankles by using a validated magnetic resonance imaging (MRI)-based measurement system.

METHODS

In this radiologic study, 34 healthy volunteers underwent a series of ankle MRIs with the ankle stabilized in 3 positions: neutral position (NP), dorsiflexion (DF), and plantarflexion (PF). Using a previously validated measurement system, 6 fixed translational measurements and 2 fixed angles were recorded on each MRI and compared using paired t tests.

RESULTS

When comparing PF to DF, the anterior distance between the tibial incisura and the fibula varied from 2.5 mm to 3.9 mm ( P < .001), respectively. The middle distance between the tibial incisura and the fibula varied from 1.5 mm to 2.6 mm ( P < .001). Fibular angle varied from 8.7 degrees to 7.8 degrees of internal rotation ( P = .046), respectively. When comparing NP to DF, only the anterior distance was found to be significantly different, varying 0.4 mm ( P < .002).

CONCLUSIONS

Ankle dorsiflexion leads to an increase in external rotation and lateral translation of the fibula. These changes could be measured on MRI using a validated measurement system. Ankle motion did have an impact on the distal tibiofibular relationship and should be considered in studies pertaining to syndesmosis imaging.

CLINICAL RELEVANCE

This is the first in vivo study demonstrating the impact of sagittal ankle position on the distal tibiofibular relationship in an uninjured ankle. Our findings also support the practice of placing the ankle in dorsiflexion when fixing a disrupted syndesmosis.

LEVEL OF EVIDENCE

Level III, comparative study.

Cadaveric Analysis of the Distal Tibiofibular Syndesmosis

BACKGROUND

Unstable ankle fractures with syndesmotic injuries commonly occur and can result in significant morbidity. Although the need for an anatomic reduction is clear, there is still debate surrounding the optimal operative treatment. Recent literature shows an increasing interest in anatomic ligament repair or reconstruction in the acute and chronic syndesmosis injury. Despite this trend, there is insufficient literature detailing anatomy of the distal tibiofibular syndesmosis. In the literature that does exist, there is controversy regarding the ligamentous anatomy of the syndesmosis. None of the current literature describes an anatomic constant that may be used as an intraoperative reference for anatomic ligament reconstructions.

METHODS

Ten sets of tibia and fibula free of all soft tissue were used to analyze osseous structures. Another 10 nonpaired, fresh-frozen specimens were used to study the distal tibiofibular syndesmosis. These were measured using a 3-dimensional tracking system. Measurement of each ligament width at origin and insertion, length, and distance from the tibial articular cartilage was performed.

RESULTS

The superior and inferior insertions of the anterior inferior tibiofibular ligament measured 22.7 mm and 3.4 mm proximal to the distal articular cartilage of the tibia, respectively. The superior insertion of the posterior inferior tibiofibular ligament measured 15.2 mm proximal to the articular cartilage. The superior and inferior insertions of the interosseous ligament measured 31.8 mm and 9.2 mm proximal to the distal articular cartilage, respectively. The inferior transverse ligament was a prominent identifiable structure in 70% of specimens.

CONCLUSIONS

The superior margin of the distal articular cartilage could serve as a consistent anatomic landmark for reconstruction. The inferior transverse ligament is an identifiable structure in 70% of the specimens studied.

CLINICAL RELEVANCE

This article clarifies the anatomy and provides measurements from an anatomic constant that can guide reconstruction and intraoperative evaluation of the syndesmosis.

Correlation and comparison of syndesmosis dimension on CT and MRI

INTRODUCTION

Various methods using CT scan have been described to diagnose distal tibiofibular syndesmotic injuries. However, CT scan does not take into account the amount of cartilage within the distal tibiofibular joint and could therefore lead to false positive results. We present the first study correlating the findings of the distal tibiofibular syndesmosis on CT and MRI scans.

METHODS

CT and MRI scan of consecutive patients over a period of 18 months, and of a time lapsed less than 12 months between the two imaging modalities, were reviewed. Measurements of the distal tibiofibular syndesmosis were taken according to a previously published study at the level of the distal tibial physeal scar.

RESULTS

Twenty-six ankles from 25 patients were included in this study for analysis. Significant difference between CT and MRI assessments in the overall distal tibiofibular dimensions and in the posterior distal tibiofibular distance for those ankles with evidence of osteoarthritis was found. Interclass correlation coefficients suggest that such methodology was reproducible and reliable.

CONCLUSION

When the widening found on a CT scan is minor or the diagnosis is equivocal, a contralateral comparative CT or an ipsilateral MRI scan is recommended to prevent misdiagnosis.

LEVEL OF EVIDENCE

Level IV.

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.

Endoscopic Distal Tibiofibular Syndesmosis Arthrodesis

Chronic distal tibiofibular syndesmosis disruption can be managed by endoscopic arthrodesis of the syndesmosis. This is performed through the proximal anterolateral and posterolateral portals. The scar tissue and bone block are resected to facilitate the subsequent reduction of the syndesmosis. The reduction of the syndesmosis can be guided either arthroscopically or endoscopically. The tibial and fibular surfaces of the tibiofibular overlap can be microfractured to facilitate subsequent fusion.

Targeted computerised tomography scanning of the ankle syndesmosis with low dose radiation exposure

OBJECTIVES

To devise a new protocol for targeted CTscanning of the distal tibiofibular syndesmosis with minimal radiation exposure to patients. We also aimed to correlate the reduction of the syndesmosis as seen on CT scans with the functional outcome of patients.

MATERIALS AND METHODS

Prospective study. Forty adults undergoing surgical stabilisation of an acute distal tibiofibular syndesmosis injury were recruited. A targeted five-cut computerised tomography scan protocol was developed. The radiation exposure to the patient with this protocol was only 0.002 mSv. Scans were performed 12 weeks after surgery. The contralateral ankle of every patient was used as a control to determine the accuracy of the reduction of the syndesmosis for that individual patient. American Orthopaedic Foot and Ankle Society (AOFAS) scores were obtained at a minimum of 1 year after surgery.

RESULTS

After considering the exclusions, 36 patients formed the study group. A wide variation was observed in the anatomy of the normal syndesmosis. If we considered a difference of more than 2 mm between the normal and injured syndesmosis relationship as significant, 15 (41.6 %) of our patients had a significant difference between the injured and normal sides. AOFAS scores were available for 13 of these patients and were good to excellent in 11(84.6 %).

CONCLUSION

Our study describes a reliable new CT scanning technique for the distal tibiofibular syndesmosis using only five cuts and a low-radiation-dose protocol. Clinical correlation of the findings on the scan with functional outcomes suggests that routine post-operative CT of the syndesmosis is probably not justified.

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.

Dynamic high-resolution US of ankle and midfoot ligaments: normal anatomic structure and imaging technique

The ankle is the most frequently injured major joint in the body, and ankle sprains are frequently encountered in individuals playing football, basketball, and other team sports, in addition to occurring in the general population. Imaging plays a crucial role in the evaluation of ankle ligaments. Magnetic resonance imaging has been proven to provide excellent evaluation of ligaments around the ankle, with the ability to show associated intraarticular abnormalities, joint effusion, and bone marrow edema. Ultrasonography (US) performed with high-resolution broadband linear-array probes has become increasingly important in the assessment of ligaments around the ankle because it is low cost, fast, readily available, and free of ionizing radiation. US can provide a detailed depiction of normal anatomic structures and is effective for evaluating ligament integrity. In addition, US allows the performance of dynamic maneuvers, which may contribute to increased visibility of normal ligaments and improved detection of tears. In this article, the authors describe the US techniques for evaluation of the ankle and midfoot ligaments and include a brief review of the literature related to their basic anatomic structures and US of these structures. Short video clips showing dynamic maneuvers and dynamic real-time US of ankle and midfoot structures and their principal pathologic patterns are included as supplemental material. Use of a standardized imaging technique may help reduce the intrinsic operator dependence of US. Online supplemental material is available for this article.

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.

Fate of the syndesmotic screw--Search for a prudent solution

INTRODUCTION

Ankle fractures are common injuries. Since the recognition of the importance of syndesmotic injury in ankle fractures, much of the scientific work has been focused on concomitant syndesmotic injury. Despite the invention of novel devices for restoration and maintenance of the congruent syndesmosis following syndesmotic injury, the metallic syndesmotic screw is still considered to be the "gold standard". The aim of this study was to compare the clinical results in patients who retained the syndesmosis screw with those in whom the screw was removed following open reduction and internal fixation of the malleolar fracture associated with syndesmosis disruption.

MATERIALS AND METHODS

This was a retrospective study of 82 patients. Minimum follow-up was 12 months. Clinical evaluation included American Orthopaedic Foot and Ankle Society (AOFAS) score and Visual Analogue Scale (VAS) for patient general satisfaction. The condition of the screw (removed, intact or broken), presence of radiolucency around the syndesmotic screw and the tibiofibular clear space were recorded using final follow-up radiographs.

RESULTS

Three cortices were engaged in 66 patients (80%) and quadricortical fixation was performed in the remaining 16 patients (20%). The number of engaged cortices did not correlate with the clinical outcome and screw fracture. A single syndesmotic screw was used in 71 patients (86%. The mean AOFAS score in the group with intact screw (I) was 83; the scores in the group with broken screw (B) and removed screw (R) were 92.5 and 85.5, respectively. There was a statistically significant difference between the three groups: this was due to the difference between groups I and B; the difference between groups I and R and groups B and R were not statistically significant. There were no statistically significant differences in VAS results.

CONCLUSION

There were no statistically significant differences in clinical outcome between the group with the screw retained and the group in which the screw was removed; however, the group with broken screws had the best clinical outcome based on AOFAS score. Widening of the syndesmosis after screw removal was not evident. We do not recommend routine syndesmosis screw removal.