Delayed operative treatment of syndesmotic instability. Current concepts review

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparative Study for Surgical Treatment of Acute Distal Tibiofibular Syndesmotic Lesions Using the Modified Suture-Button Fixation Versus Static Syndesmotic Screw Fixation

INTRODUCTION

Several techniques to treat acute distal tibiofibular instability are described consisting in static and dynamic fixation procedures. The aim of our work is to compare the outcomes of acute syndesmotic injury fixation between the modified technique of dynamic fixation using the suture-button principle as an efficient and low-cost method and the classic static fixation.

METHODS

It is a prospective study including patients presenting with acute syndesmotic injury. After fracture fixation, residual syndesmotic instability was managed using syndesmotic screw in group A and dynamic fixation with a double Ethibond suture in group B. Functional results were assessed using the American Orthopaedic Foot and Ankle Society score (AOFAS) score. Radiological evaluation was done by a postoperative computed tomography (CT) scan of both ankles and plain X-rays of the ankle after surgery and at 18 months.

RESULTS

Group A included 20 patients meanwhile 35 patients were in group B. The reduction was satisfactory in the 2 groups according to the postoperative CT scan measurements. The mean healing time in group A was 49.65 days and 51.49 days in group B (P = .45). We did not find any significant difference in terms of loss of reduction in the 2 groups. The return to work was faster in group B (P = .04). Patients in group B had better AOFAS score (P = .03) and ankle range of motion than those in group A. The difference was statistically significant (P = .02 for dorsal flexion and P = .001 for plantar flexion). For group A, we did not note any early complications. Meanwhile, 7 patients developed skin complications in group B (P = .03). However, no significant difference was found in terms of late complications.

CONCLUSIONS

The modified dynamic suture-button fixation remains a therapeutic alternative in low-income countries that could achieve better outcomes than static fixation, with easy postoperative follow-up.

LEVELS OF EVIDENCE

Level II.

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.

The use of deep learning enables high diagnostic accuracy in detecting syndesmotic instability on weight-bearing CT scanning

PURPOSE

Delayed diagnosis of syndesmosis instability can lead to significant morbidity and accelerated arthritic change in the ankle joint. Weight-bearing computed tomography (WBCT) has shown promising potential for early and reliable detection of isolated syndesmotic instability using 3D volumetric measurements. While these measurements have been reported to be highly accurate, they are also experience-dependent, time-consuming, and need a particular 3D measurement software tool that leads the clinicians to still show more interest in the conventional diagnostic methods for syndesmotic instability. The purpose of this study was to increase accuracy, accelerate analysis time, and reduce interobserver bias by automating 3D volume assessment of syndesmosis anatomy using WBCT scans.

METHODS

A retrospective study was conducted using previously collected WBCT scans of patients with unilateral syndesmotic instability. One-hundred and forty-four bilateral ankle WBCT scans were evaluated (48 unstable, 96 control). We developed three deep learning models for analyzing WBCT scans to recognize syndesmosis instability. These three models included two state-of-the-art models (Model 1-3D Convolutional Neural Network [CNN], and Model 2-CNN with long short-term memory [LSTM]), and a new model (Model 3-differential CNN LSTM) that we introduced in this study.

RESULTS

Model 1 failed to analyze the WBCT scans (F1 score = 0). Model 2 only misclassified two cases (F1 score = 0.80). Model 3 outperformed Model 2 and achieved a nearly perfect performance, misclassifying only one case (F1 score = 0.91) in the control group as unstable while being faster than Model 2.

CONCLUSIONS

In this study, a deep learning model for 3D WBCT syndesmosis assessment was developed that achieved very high accuracy and accelerated analytics. This deep learning model shows promise for use by clinicians to improve diagnostic accuracy, reduce measurement bias, and save both time and expenditure for the healthcare system.

LEVEL OF EVIDENCE

II.

Bilateral ankle syndesmosis injury: a rare case report

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

The Syndesmosis, Part I: Anatomy, Injury Mechanism, Classification, and Diagnosis

Ankle fractures are common injuries to the lower extremity with approximately 20% sustaining a concomitant injury to the syndesmosis. Although the deltoid ligament is not formally included in the syndesmotic complex, it plays an important role in the mortise stability. Therefore, its integrity should be always evaluated when syndesmotic injury is suspected. Given the anatomic variability of the syndesmosis between individuals, bilateral ankle imaging is recommended, especially in cases of subtle instability. Diagnostic tests that allow dynamic assessment of the distal tibiofibular joint in the 3 planes are the most reliable in determining the presence of syndesmotic injury.

Chronic Syndesmotic Injury: Revision and Fixation With a Suture Button and a Quadricortical Screw

Background. Chronic syndesmotic injury may cause long-term pain and reduced ankle function. Today, there is no consensus about the best surgical treatment of these injuries. We present the technique and results of revision and fixation with a suture button and a quadricortical screw. Methods. Eleven patients treated for chronic syndesmotic injury were included. The patients completed questionnaires regarding ankle function, and computed tomography scans were obtained to evaluate tibiofibular distance and osteoarthritis. Complications were registered. Results. At mean 45 months follow-up, the mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score was 87 points. There were 5 complications, including 3 hardware-related pain. The tibiofibular distance was significantly reduced with surgery. Seven patients had progression of osteoarthritis. Conclusions. Even though the majority of the patients had progression of radiological signs of osteoarthritis, the functional outcome after revision and fixation with a suture button and a quadricortical screw in chronic syndesmotic ruptures is good and comparable to the results presented in other studies.Levels of Evidence: Level IV: Case series without control, technical note.

Arthroscopic characterization of syndesmotic instability in the coronal plane: Exactly what measurement matters?

BACKGROUND

Although ankle arthroscopy is increasingly used to diagnose syndesmotic instability, precisely where in the incisura one should measure potential changes in tibiofibular space or how much tibiofibular space is indicative of instability, however, remains unclear. The purpose of this study was to determine where within the incisura one should assess coronal plane syndesmotic instability and what degree of tibiofibular space correlates with instability in purely ligamentous syndesmotic injuries under condition of lateral hook stress test (LHT) assessment.

METHODS

Ankle arthroscopy was performed on 22 cadaveric specimens, first with intact ankle ligaments and then after sequential sectioning of the syndesmotic and deltoid ligaments. At each step, a 100N lateral hook test was applied through a lateral incision 5 cm proximal to the ankle joint and the coronal plane tibiofibular space in the stressed and unstressed states were measured at both anterior and posterior third of the distal tibiofibular joint, using calibrated probes ranging from 0.1 to 6.0 mm, in 0.1 mm of increments. The anterior and posterior points of measurements were defined as the junction between the anterior and middle third, and junction between posterior and middle third of the incisura, respectively.

RESULTS

Anterior third tibiofibular space measurements did not correlate significantly with the degree of syndesmotic instability after transection of the ligaments, neither before nor after applying LHT at all the three groups of different sequences of ligament transection (P range 0.085-0.237). In contrast, posterior third tibiofibular space measurements correlated significantly with the degree of syndesmotic instability after transection of the ligaments, both with and without applying stress in all the groups of different ligament transection (P range <0.001-0.015). Stressed tibiofibular space measurements of the posterior third showed higher sensitivity and specificity when compared to the stressed anterior third measurements. Using 2.7 mm as a cut off for posterior third stressed measurements has both sensitivity and specificity about 70 %.

CONCLUSION

Syndesmotic ligament injury results in coronal plane instability of the distal tibiofibular articulation that is readily identified arthroscopically with LHT when measured in the posterior third of the incisura.

CLINICAL RELEVANCE

When applying LHT, tibiofibular space measurement for coronal plane instability along the anterior third of the incisura is less sensitive for identifying syndesmotic instability and may miss this diagnosis especially when subtle.

Functional outcome of fusion versus ligament reconstruction in patients with a syndesmosis injury: A narrative review

Injury to distal tibiofibular syndesmosis is commonly associated with ankle fractures. The surgical treatment especially in isolated chronic syndesmosis instability is still debated. This article has reviewed literature identified from PubMed, EMBASE and Cochrane from year 2000 onwards and compared the functional outcomes between syndesmosis fusion and ligament reconstruction based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eighteen studies were included. All the included papers described a good-to-excellent post-operative functional outcome without major complications. No significant difference between the two surgical interventions could be concluded. Further studies of better quality shall be conducted in the future.

Syndesmotic Ligament Allograft Reconstruction for Treatment of Chronic Diastasis

Chronic diastasis after a syndesmotic injury can lead to ankle joint instability and loss of joint congruence. Failure to restore the fibula into the proper anatomic position within the incisura increases the focal stress on the talus and can accelerate degenerative joint destruction. In the case of failed syndesmotic repair, fixation options are limited. If promptly diagnosed, the syndesmosis may be amenable to open debridement and subsequent fixation with 2 interosseous screws. If latent diastasis is found, however, syndesmotic fusion by bone block arthrodesis is recommended. We present a syndesmotic allograft repair technique for surgical reconstruction of chronic unstable syndesmotic ruptures.

Comparison of Ligament-Repair Techniques for the Syndesmosis: A Simulated Cadaveric Weight-Bearing Computed Tomography Analysis

Although the literature describes a variety of reconstructive techniques for the syndesmosis, only few studies offer comparative data. Therefore, the authors compared 2 different ligament repair techniques for the syndesmosis. Sixteen paired fresh-frozen human cadaveric lower limbs were embedded in polymethyl methacrylate mid-calf and placed in a custom-made weightbearing simulation frame. Computed tomography scans of each limb were obtained in a simulated foot-flat loading (75N) and single-leg stance (700N) in 5 different foot positions (previously reported data). One of each pair was then reconstructed via 1 of 2 methods: a free medial Achilles tendon autograft or a long peroneal tendon ligament repair. The specimens were rescanned, compared with their respective intact states and directly with each other. Measurements of fibular diastasis, rotation, anteroposterior translation, mediolateral translation, and fibular shortening were performed on the axial cuts of the computed tomography scans, 1 cm proximal to the roof of the plafond. There was no significant difference in fibular positioning with direct comparison of the reconstructions. Comparisons with their respective intact states, however, showed differences in their abilities to control reduction, most notably in the externally rotated and dorsiflexed positions of the foot. Neither reconstruction was clearly superior in restoring physiologic conditions. Only with a comparison of each technique to its respective intact state were differences between the techniques revealed, a benefit of this particular testing method.

Maisonneuve injury with no fibula fracture: A case report

BACKGROUND

Ankle syndesmosis injury is difficult to diagnose accurately at the initial visit. Missed diagnosis or improper treatment can lead to chronic complications. Complete syndesmosis injury with a concomitant rupture of the interosseous membrane (IOM) is more unstable and severe. The relationship between this type of injury and Maisonneuve injury, in which the syndesmosis is also injured, has not been discussed in the literature previously.

CASE SUMMARY

A 16-year-old patient sustained left medial malleolar fracture, and the associated inferior tibiofibular syndesmotic instability was overlooked. After open reduction and internal fixation of the medial malleolar fracture, inferior tibiofibular syndesmosis diastasis with IOM rupture was detected by auxiliary imaging. Secondary surgical intervention was performed to reduce anatomically and fix with two trans-syndesmosis screws. Twelve weeks later, the screws were removed. At the 6-mo follow-up, the patient gained full range of motion of the ankle.

CONCLUSION

Complete syndesmosis injury with IOM rupture should be considered Maisonneuve-type injury. Open reduction and internal fixation could obtain good outcomes.

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.

Hybrid Fixation for Danis-Weber Type C Fractures With Syndesmosis Injury

BACKGROUND

This study aimed to assess the clinical and radiological outcomes of hybrid fixation for Danis-Weber type C ankle fractures with a syndesmotic injury.

METHODS

From January 2016 to April 2018, we retrospectively reviewed consecutive patients who underwent hybrid fixation for Danis-Weber type C ankle fractures with syndesmotic injury with a minimum follow-up of 12 months. We excluded patients who achieved syndesmosis stability after fracture fixation. In all patients, we allowed partial weightbearing at 4 weeks postoperatively. We evaluated the visual analog scale for ankle pain, the Olerud-Molander ankle score, and the American Orthopaedic Foot & Ankle Society score. Malreduction of the syndesmosis was defined based on 2 previously reported methods. Fourteen patients (11 men and 3 women) were included in this study. There were 11 patients with pronation external rotation-type fractures and 3 patients with Maisonneuve fractures. The average age at operation was 37.2 years (range, 18-70 years).

RESULTS

Clinical scores were significantly improved at the last follow-up. Postoperative malreduction was observed only in 1 patient (7.1%).

CONCLUSION

Hybrid fixation using a suture-button device combined with a syndesmotic screw in Danis-Weber type C fractures with syndesmosis injury showed a high accuracy of reduction, a low rate of diastasis, and favorable clinical outcomes. This combined method could be a good alternative treatment option for Danis-Weber type C ankle fractures with a syndesmosis injury.

LEVEL OF EVIDENCE

Level IV, case series.

Traumatic injuries of the distal tibiofibular syndesmosis

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

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."

Reconstruction of tibiofibular syndesmosis using autologous semitendinosus graft and lengthening derotational osteotomy of the distal fibula

Distal tibiofibular syndesmosis is a complex anatomical structure that is essential for the stability and function of the ankle. Ankle fractures are a common source of chronic syndesmosis instability with associated functional impairments and early development of osteoarthritis. Case presentation: we described a case of a 28-year-old patient who presented with symptomatic ankle subluxation and chronic syndesmosis instability. Eight months earlier, the patient sustained a minimally displaced ankle fracture that had been treated conservatively elsewhere. The surgical approach included the anatomical realignment of the distal fibula with a lengthening derotational osteotomy and tibiofibular syndesmosis reconstruction using an autologous semitendinosus tendon graft. One year after surgery, the ankle function was restored, and the patient was asymptomatic. Conclusion: The instability of ankle fractures should be carefully evaluated during the treatment decision-making. Surgical treatment of syndesmosis instability should be performed even in chronic cases to restore function. The reconstruction of syndesmosis with semitendinous tendon graft associated with fibular length and realignment improves the ankle stability and function.

Acute and Chronic Syndesmotic Instability: Role of Surgical Stabilization

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

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.

Surgical outcome in chronic syndesmotic injury: A systematic literature review

BACKGROUND

Chronic injuries of the distal tibio-fibular syndesmosis often present with non-specific clinical and radiographic findings. If chronic instability to the distal tibio-fibular syndesmosis is verified, various reconstruction options are available. The purpose of this article is to give a systematic review of current surgical treatment options in patients with chronic syndesmotic injury.

METHODS

Three major medical databases were searched from inception through December 12, 2017: PubMed, ScienceDirect, and SpringerLink. Studies were included if they were original research studies which assessed the outcome of patients treated surgically for chronic syndesmotic instability. Only studies written in English were considered. The following data were extracted from each study: number of patients and ankles included, average patients' age, gender, study design, preoperative examination, time between the initial injury and the operation, postoperative follow-up time, operative technique, complication rates, and clinical outcome. The modified Coleman Score was used to assess the methodologic quality of the included studies.

RESULTS

Seventeen (17) studies were included. All studies were retrospective or prospective case series. Each study was performed at a single center. In general, good functional outcomes and low complication rates were reported. The American Orthopaedic Foot and Ankle (AOFAS) score was most frequently used outcome tool to measure postoperative outcomes. The quality of the included studies was overall satisfactory.

CONCLUSIONS

A few studies have reported on the operative outcomes after treating chronic syndesmotic instability. Several different techniques were used to treat this problem. The quality of current studies is overall satisfactory but could be improved with larger patient numbers and prospective analysis. Recognition of this clinical entity as an identifiable and treatable cause of ankle pain requires vigilant clinical investigation.

LEVEL OF EVIDENCE

Level IV; Systematic Review of Level IV Studies.

Arthroscopic Reduction and Minimally Invasive Surgery in Supination-External Rotation Ankle Fractures: A Comparative Study With Open Reduction

PURPOSE

To describe an algorithm for arthroscopic reduction and minimally invasive surgery (ARMIS) and compare the surgical outcomes with standard open reduction-internal fixation (ORIF) for the treatment of supination-external rotation (SER) ankle fractures.

METHODS

The inclusion criteria for this study were patients aged 16 years or older, the presence of a unilateral SER fracture, and injuries less than 2 weeks old. We retrospectively identified patients with SER fractures who underwent ORIF from January 2008 to December 2011 or ARMIS from January 2012 to December 2015. Data collected in December 2013 for the ORIF group and in December 2017 for the ARMIS group were compared. The algorithm for ARMIS was minimally invasive plating for lateral malleolar fractures first, followed by ankle arthroscopy for detection of syndesmotic injuries and then arthroscopic reduction of medial malleolar fractures or mini-open repair of the deltoid ligament. The talocrural angle, fibular length, tibiomedial malleolar angle, medial clear space, and tibiofibular clear space were measured radiographically. Functional evaluations included the visual analog scale pain score, American Orthopaedic Foot & Ankle Society ankle-hindfoot scales, and range of motion of bilateral ankles. Complications and reoperations were recorded for comparison.

RESULTS

A total of 105 patients with SER fractures, 65 in the ARMIS group and 40 in the ORIF group, were included. Significantly lower incidences of complications (7.7% vs 27.5%, P = .006) and reoperations (1.5% vs 12.5%, P = .029) were found in the ARMIS group than in the ORIF group. More syndesmotic injuries were detected in the ARMIS group than in the ORIS group (80% vs 57.5%, P = .021). The visual analog scale pain score was significantly lower on day 3 postoperatively in the ARMIS group than in the ORIS group (1.96 ± 1.18 vs 2.83 ± 1.07, P = .027). The postoperative stay was shorter in the ARMIS group than in the ORIF group (3.66 ± 1.39 days vs 4.46 ± 2.23 days, P = .024). The operative time was longer in the ARMIS group than in the ORIS group (105.22 ± 27.13 minutes vs 93.59 ± 22.79 minutes, P = .038). A longer fluoroscopic time (0.43 ± 0.25 minutes vs 0.17 ± 0.07 minutes, P < .001) and a higher dose of irradiation (1,216.46 ± 603.99 μGy vs 389.38 ± 217.89 μGy, P < .001) were observed in the ARMIS group. No significant differences in radiographic measurements were found between the operative and nonoperative ankles in both groups.

CONCLUSIONS

Our algorithm and the ARMIS techniques may be a safe, reliable, and effective option in the treatment of SER fractures. ARMIS achieves promising surgical outcomes with less early postoperative pain, a shorter postoperative stay, and lower incidences of complications and reoperations compared with ORIF. However, the operative time is longer and the irradiation dose is higher with the ARMIS techniques.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Syndesmosis Fixation in Unstable Ankle Fractures Using a Partially Threaded 5.0-mm Cannulated Screw

The present study evaluated the radiographic outcomes of syndesmosis injuries treated with a partially threaded 5.0-mm cannulated screw. The present study included 58 consecutive patients with syndesmosis injuries concurrent with ankle fractures who had undergone operative fixation with a partially threaded 5.0-mm cannulated screw to repair the syndesmosis injury. Radiographic indexes, including the medial clear space, tibiofibular overlap, tibiofibular clear space, and fibular position on the lateral radiograph, were measured on the preoperative, immediate postoperative, and final follow-up radiographs. The measurements were compared between the injured and intact ankles. All preoperative radiographic indexes, including the medial clear space (p < .001), tibiofibular overlap (p < .001), tibiofibular clear space (p < .001), and fibular position on the lateral radiograph (p = .026), were significantly different between the injured and intact ankles. The medial clear space of the injured ankle was significantly wider than that of the intact ankle preoperatively (p < .001) and had become significantly narrower immediately postoperatively (p < .001). Finally, the medial clear space was not significantly different between the injured and intact ankles at the final follow-up examination (p = .522). No screw breakage or repeat fractures were observed. A 5.0-mm partially threaded cannulated screw effectively restored and maintained the normal relationship between the tibia and fibula within the ankle mortise with a low risk of complications. This appears to be an effective alternative technique to treat syndesmosis injuries concurrent with ankle fractures.

Correlation factors for distal syndesmosis ossification following internal fixation of ankle fracture

This clinical retrospective study explored factors associated with distal tibiofibular syndesmosis ossification (TFSO) after ankle fracture fixation. Between August 2012 and January 2015, 172 patients with ankle fractures (121 men) with an average age of 46.6 years (range, 22–71 years) were treated surgically with an average follow-up period of 26 months (range, 16–34 months). According to the Danis-Weber AO classification rubric, 54 fractures were type A, 78 were type B, and 40 were type C. According to the Lauge-Hansen classification, there were 17 supination-adduction (SA) fractures, 98 supination-external rotation (SE) fractures, 31 pronation-external rotation (PE) fractures, and 26 pronation-abduction (PA) fractures. The average injury to operation interval was 4.3 days (6 hours-7 days). Multiple factor analysis was conducted to examine risk factors for TFSO. It was observed in 36 (20.9%) cases (11 complete ossification cases; 25 partial ossification cases). Multivariate logistic regression revealed the following independent risk factors for TFSO were: AO classification, distal tibiofibular syndesmosis separation, and fibular fracture morphology. In conclusion, AO type C fracture, syndesmosis separation, and high fibular fracture were associated with distal TFSO following ankle fracture fixation.

Morphology of the Incisura Fibularis at the Distal Tibiofibular Syndesmosis in the Japanese Population

The morphology of the distal tibiofibular syndesmosis can determine the pathology and mechanism of syndesmotic injury. The present study assessed measurements obtained from computed tomography (CT) images of the normal distal tibiofibular syndesmosis in Japanese subjects. CT scans of 120 right feet with a normal distal tibiofibular syndesmosis obtained from January 2009 to December 2016 were retrospectively assessed at the level 10 mm proximal to the tibial plafond. The incisura fibularis was considered concave when its depth was ≥4 mm and shallow when its depth was <4 mm. The depth of the incisura fibularis, anterior tibiofibular distance (TFD), posterior TFD, and longitudinal/transverse length of the distal fibula were measured. The incisura fibularis was concave in 64.2% of the feet and shallow in 35.8%. The mean anterior TFD was 2.2 ± 0.8 mm (2.4 ± 0.8 mm in males; 2.1 ± 0.8 mm in females; 2.1 ± 0.8 mm for concave; 2.2 ± 0.9 mm for shallow). The mean posterior TFD was 5.9 ± 1.6 mm (6.7 ± 2.1 in males; 5.7 ± 1.3 mm in females; 5.5 ± 1.3 mm for concave; 6.5 ± 1.9 mm for shallow). The mean longitudinal/transverse length of the distal fibula at the level of the syndesmosis was 1.2 mm (1.3 mm in males; 1.2 mm in females; 1.1 mm for concave; 1.3 mm for shallow). The mean posterior TFD was significantly greater than the mean anterior TFD and was also significantly greater in males than in females. Significant differences were found in the body mass index, posterior TFD, and longitudinal/transverse length of the distal fibula according to whether the incisura fibularis was concave or shallow. The present study has provided measurements of the normal tibiofibular syndesmosis in the Japanese population. These data suggest that the morphology of the syndesmosis varies, especially with respect to whether the incisura fibularis is concave or shallow.

A Radiographic Dye Method for Intraoperative Evaluation of Syndesmotic Injuries

BACKGROUND

The Chertsey test has been recently defined as an intraoperative test for the detection of the syndesmotic injuries by the application of intra-articular contrast. However, no study has investigated the reliability and comparative analysis of the Chertsey test. The purpose of this study was to explore the diagnostic accuracy of the Chertsey test in predicting syndesmosis instability of the injured ankle, with correlation to preoperative computed tomography (CT) findings.

METHODS

A total of 39 patients who were operated on due to the unilateral ankle fracture and had no complaint on the contralateral ankle joint were included in the study. An intraoperative Chertsey test was performed on all ankle fractures and bilateral ankle CT was obtained preoperatively. Ankles were classified as Chertsey +, Chertsey -, and contralateral control group. The morphology categorization, width, and volume of the syndesmotic region were measured on axial images of the CT. Mann-Whitney U test was used to compare the data. Intraobserver and interobserver agreements were accessed by calculating the intraclass correlation coefficient (ICC) for radiologic parameters and the Chertsey test.

RESULTS

The Chertsey test was positive in 13 (33.3%) of 39 ankle fractures. Patients with a positive Chertsey test showed a significant increase in syndesmotic width and volume compared with Chertsey - and control group. However, there was no significant difference between Chertsey - and the control group. All the ICC values were excellent for both radiologic measurements and test.

CONCLUSION

The Chertsey test is a reliable and useful test that can be used intraoperatively in the diagnosis of syndesmotic injuries.

LEVEL OF EVIDENCE

III, comparative series.

Management of syndesmotic injuries of the ankle

Injuries to the tibioperoneal syndesmosis are more frequent than previously thought and their treatment is essential for the stability of the ankle mortise.

Recognition of these lesions is essential to avoid long-term morbidity.

Diagnosis often requires complete history, physical examination, weight-bearing radiographs and MRI.

Treatment-oriented classification is mandatory.

It is recommended that acute stable injuries are treated conservatively and unstable injuries surgically by syndesmotic screw fixation, suture-button dynamic fixation or direct repair of the anterior inferior tibiofibular ligament.

Subacute injuries may require ligamentoplasty and chronic lesions are best treated by syndesmotic fusion.

However, knowledge about syndesmotic injuries is still limited as recommendations for surgical treatment are only based on level IV and V evidence.

Cite this article: EFORT Open Rev 2017;2:403–409. DOI: 10.1302/2058-5241.2.160084

Current trends in the diagnosis and management of syndesmotic injury

Ideal management of the various presentations of syndesmotic injury remains controversial to this day. High quality evidentiary science on this topic is rare, and numerous existing studies continue to contradict one another. The primary reasons for these discrepancies are that previous studies have failed to (1) properly distinguish between isolated (non-fractured) and non-isolated injuries, (2) accurately define stable from unstable injuries, and (3) sufficiently differentiate between acute and chronic injuries. The purpose of this review is to summarize today's body of literature regarding diagnosis and management of syndesmotic injury and discuss current trends and important future directions to optimize care of this very heterogeneous population.

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.

Management of sports injuries of the foot and ankle

Sporting injuries around the ankle vary from simple sprains that will resolve spontaneously within a few days to severe injuries which may never fully recover and may threaten the career of a professional athlete. Some of these injuries can be easily overlooked altogether or misdiagnosed with potentially devastating effects on future performance. In this review article, we cover some of the common and important sporting injuries involving the ankle including updates on their management and outcomes.

Cite this article: Bone Joint J 2016;98-B:874–83.

Treatment of a Neglected Syndesmotic Injury Using a Unique Method of Reduction

Syndesmotic injuries are challenging in diagnosis and management as delays in treating the injury lead to poorer functional outcomes. In this case report, we discuss management of an untreated Maisonneuve fracture. To our knowledge, our technique of using a composite braided suture with internal buttons fixed from the talus to the medial malleolus to supplement our syndesmotic repair has not previously been described.

Biomechanical comparison of bionic, screw and Endobutton fixation in the treatment of tibiofibular syndesmosis injuries

BACKGROUND

The two prevalent fixation methods in the treatment of syndesmosis injuries, the rigid screw fixation and flexible Endobutton fixation, are not without issues; thus, we have designed a novel bionic fixation method which combines the features of both rigid and flexible fixations. The aim of this study was to compare the biomechanical properties of the bionic fixation to the screw and Endobutton fixations.

METHODS

Six normal fresh-frozen legs from amputation surgery were used. After initial tests of intact syndesmosis, screw, bionic and Endobutton fixations were performed sequentially for each specimen. Axial loading as well as rotation torque were applied, in five different ankle positions: neutral position, dorsiflexion, plantar flexion, varus, and valgus. The displacement of the syndesmosis and the tibial strain were analysed using a biomechanical testing system.

RESULTS

Whether receiving axial loading or rotation torque, in most situations (neutral position, dorsiflexion, varus, plantar flexion with low loading, valgus with high loading, internal and external rotation), the bionic group and Endobutton group had comparable displacements, and there was no significant difference among the intact, bionic, and Endobutton groups; whereas the displacements of the screw group were smaller than any of the other three groups. Results of the tibial strain were similar with that of the displacement.

CONCLUSIONS

The bionic fixation at least equals the performance of Endobutton fixation; it also allows more physiologic movement of the syndesmosis when compared to the screw fixation and may serve as a viable option for the fixation of the tibiofibular syndesmosis.

Concomitant Syndesmotic Instability and Medial Ankle Instability Are Risk Factors for Unsatisfactory Outcomes in Patients With Chronic Ankle Instability

PURPOSE

To determine whether concomitant chronic syndesmotic injury or chronic medial ankle instability is associated with unsatisfactory outcomes in patients with chronic lateral ankle instability (CAI).

METHODS

We conducted a retrospective review of prospectively collected data from 276 male military patients with CAI who had undergone a modified Broström procedure between May 2007 and March 2010 and had been followed up for a mean of 26.7 months (range, 22 to 41 months). We evaluated clinical outcomes using American Orthopaedic Foot & Ankle Society ankle-hindfoot, visual analog scale, and ankle functional satisfactory scale scores. Possible associations with concomitant instability were reconstructed and investigated using the Pearson correlation coefficient and multivariate logistic regression analysis.

RESULTS

Of the 236 patients with satisfactory outcomes, 19 (8%) had medial ankle instability and 13 (6%) had syndesmotic instability; in contrast, of the 40 patients with unsatisfactory outcomes, 14 (35%) had medial ankle instability and 12 (30%) had syndesmotic instability. The mean American Orthopaedic Foot & Ankle Society scores for patients with satisfactory and unsatisfactory outcomes increased from 68.1 to 92.8 (P < .001) and from 65.9 to 76.8 (P < .001), respectively. The mean visual analog scale scores for the groups with satisfactory and unsatisfactory outcomes decreased from 5.8 to 2.1 (P < .001) and from 6.2 to 4.8 (P < .001), respectively. The mean ankle satisfaction score was 27.8 for patients with satisfactory outcomes and 18.7 for those with unsatisfactory outcomes (P < .001). Multivariate logistic regression analysis showed a 4-fold higher risk of dissatisfaction (95% confidence interval [CI], 0.81 to 20.07; P = .0880) with CAI and syndesmotic instability, a 3.8-fold higher risk (95% CI, 0.96 to 15.07; P = .0576) with CAI and medial ankle instability, and an 11.7-fold higher risk (95% CI, 2.60 to 52.70; P = .0014) with CAI and both syndesmotic and medial ankle instability.

CONCLUSIONS

Chronic syndesmotic instability and chronic medial ankle instability are significantly associated with unsatisfactory outcomes in patients with CAI.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Can pre-operative axial CT imaging predict syndesmosis instability in patients sustaining ankle fractures? Seven years' experience in a tertiary trauma center

OBJECTIVE

The purpose of this study is to explore the diagnostic accuracy of CT measurements in predicting syndesmosis instability of injured ankle, with correlation to operative findings.

METHODS

From July 2006 to June 2013, 123 patients presented to a single tertiary hospital who received pre-operative CT for ankle fractures were retrospectively reviewed. All patients underwent open reduction and internal fixation for fractures and intra-operative syndesmosis integrity tests. The morphology of incisura fibularis was categorized as deep or shallow. The tibiofibular distance (TFD) between the medial border of the fibula and the nearest point of the lateral border of tibia were measured at anterior (aTFD), middle (mTFD), posterior (pTFD), and maximal (maxTFD) portions across the syndesmosis on axial CT images at 10 mm proximal to the tibial plafond. Statistical analysis was performed with independent samples t test and ROC curve analysis. Intraobserver reproducibility and inter-observers agreement were also evaluated.

RESULTS

Of the 123 patients, 39 (31.7%) were operatively diagnosed with syndesmosis instability. No significant difference of incisura fibularis morphology (deep or shallow) and TFDs was demonstrated respective to genders. The axial CT measurements were significantly higher in ankles diagnosed with syndesmosis instability than the group without (maxTFD means 7.2 ± 2.96 mm vs. 4.6 ± 1.4 mm, aTFD mean 4.9 ± 3.7 mm vs. 1.8 ± 1.4 mm, mTFD mean 5.3 ± 2.4 mm vs. 3.2 ± 1.6 mm, pTFD mean 5.3 ± 1.8 mm vs. 4.1 ± 1.3 mm, p < 0.05). Their respective cutoff values with best sensitivity and specificity were calculated; the aTFD (AUC 0.798) and maxTFD (AUC 0.794) achieved the highest diagnostic accuracy. The optimal cutoff levels were aTFD =  mm (sensitivity, 56.4%; specificity, 91.7%) and maxTFD = 5.65 mm (sensitivity, 74.4%; specificity, 79.8%). The inter-observer agreement was good for all aTFD, mTFD, pTFD, and maxTFD measurements (ICC 0.959, 0.799, 0.783, and 0.865). The ICC for intraobserver agreement was also very good, ranging from 0.826 to 0.923.

CONCLUSIONS

Axial CT measurements of tibiofibular distance were useful predictors for syndesmosis instability in fractured ankles. The aTFD and maxTFD are the most powerful parameters to predict positive operative instability.

Preoperative Radiographic and CT Findings Predicting Syndesmotic Injuries in Supination-External Rotation-Type Ankle Fractures

BACKGROUND

The Lauge-Hansen classification system does not provide sufficient data related to syndesmotic injuries in supination-external rotation (SER)-type ankle fractures. The aim of the present study was to investigate factors helpful for the preoperative detection of syndesmotic injuries in SER-type ankle fractures using radiographs and computed tomography (CT).

METHODS

A cohort of 191 consecutive patients (104 male and eighty-seven female patients with a mean age [and standard deviation] of 50.7 ± 16.4 years) with SER-type ankle fractures who had undergone operative treatment were included. Preoperative ankle radiographs and CT imaging scans were made for all patients, and clinical data, including age, sex, and mechanism of injury (high or low-energy trauma), were collected. Patients were divided into two groups: the stable syndesmotic group and the unstable syndesmotic group, with a positive intraoperative lateral stress test leading to syndesmotic screw fixation. Fracture height, fracture length, medial joint space, extent of fracture, and bone attenuation were measured on radiographs and CT images and were compared between the groups. Binary logistic regression analysis was performed to identify the factors that significantly contributed to unstable syndesmotic injuries. Receiver operating characteristic curves were calculated, and cutoff values were suggested to predict unstable syndesmotic injuries on preoperative imaging measurements.

RESULTS

Of the 191 patents with a SER-type ankle fracture, thirty-eight (19.9%) had a concurrent unstable syndesmotic injury. Age, sex, mechanism of injury, fracture height, medial joint space, and bone attenuation were significantly different between the two groups. In the binary logistic analysis, fracture height, medial joint space, and bone attenuation were found to be significant factors contributing to unstable syndesmotic injuries. The cutoff values for predicting unstable syndesmotic injuries were a fracture height of >3 mm and a medial joint space of >4.9 mm on CT scans, and a fracture height of >7 mm and medial joint space of >4.5 mm on radiographs.

CONCLUSIONS

Fracture height, medial joint space, and bone attenuation were useful factors for the preoperative detection of unstable syndesmotic injuries in SER-type ankle fractures.

LEVEL OF EVIDENCE

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

A modified technique for fixation of chronic instability of the distal tibiofibular syndesmosis using a wire and button

Distal tibiofibular syndesmosis injury accounts for 1% to 11% of soft tissue injuries of the ankle. Some acute syndesmotic injuries will fail to heal effectively owing to inadequate treatment or misdiagnosis, eventually resulting in chronic instability, which can destroy the stability of the ankle joint. Various surgical techniques have been described for fixation of the syndesmosis. Among the existing methods, the suture button has the advantage of allowing for physiologic micromotion at the syndesmosis by maintaining the reduction and preventing the risk of screw breakage. However, the "relatively" long suture between buttons can gradually relax under continuous loading, resulting in fixation failure, which we have termed electric wire phenomenon. In the present report, we have described a modified technique for flexible fixation using the Endobutton CL ULTRA fixation device by tricortical fixation, instead of quadricortical fixation, to allow for robust and reliable fixation of the distal tibiofibular syndesmosis. The modified technique is devoid of the concern regarding the use of screw fixation and can reduce the risk of displacement or elongation and skin irritation associated with the suture button.

Isolated chronic anteroinferior tibiofibular ligament rupture repair

Chronic anteroinferior tibiofibular ligament tears are rarely an isolated pathology. Only a small amount of published, peer-reviewed literature exists describing the isolated repair of the syndesmotic complex in patients who present with chronic ankle pain. We present a technique to restore the anatomic stability of the ligament and syndesmotic complex. The procedure can be easily performed using allogenic semitendinosus tendon graft and stabilized with transyndesmotic screws. The graft can be secured with biotenodesis screws or anchors of the surgeon's preference. The patient described in this report had a successful outcome with no complications.

Diagnosing syndesmotic instability in ankle fractures

The precise diagnosis of distal tibiofibular syndesmotic ligament injury is challenging and a distinction should be made between syndesmotic ligament disruption and real syndesmotic instability. This article summarizes the available evidence in the light of the author’s opinion. Pre-operative radiographic assessment, standard radiographs, computed tomography scanning and magnetic resonance imaging are of limited value in detecting syndesmotic instability in acute ankle fractures but can be helpful in planning. Intra-operative stress testing, in the sagittal, coronal or exorotation direction, is more reliable in the diagnosis of syndesmotic instability of rotational ankle fractures. The Hook or Cotton test is more reliable than the exorotation stress test. The lateral view is more reliable than the AP mortise view because of the larger displacement in this direction. When the Hook test is used the force should be applied in the sagittal direction. A force of 100 N applied to the fibula seems to be appropriate. In the case of an unstable joint requiring syndesmotic stabilisation, the tibiofibular clear space would exceed 5 mm on the lateral stress test. When the surgeon is able to perform an ankle arthroscopy this technique is useful to detect syndesmotic injury and can guide anatomic reduction of the syndesmosis. Many guidelines formulated in this article are based on biomechanical and cadaveric studies and clinical correlation has to be established.

Management of chronic disruption of the distal tibiofibular syndesmosis

Disruption of the distal tibiofibular syndesmosis is frequently accompanied by rotational ankle fracture such as pronation-external rotation and rarely occurs without ankle fracture. In such injury, not only inadequately treated or misdiagnosed cases, but also correctly diagnosed cases can possibly result in a chronic pattern which is more troublesome to treat than an acute pattern. This paper reviews anatomical and biomechanical characteristics of the distal tibiofibular joint, the mechanism of chronic disruption of the distal tibiofibular syndesmosis, radiological and arthroscopic diagnosis, and surgical treatment.