Syndesmotic Ligament Injury Research Articles

Computed Tomographic Validation of the Center-Center Radiographic Technique for Syndesmosis Fixation Axis Alignment in Normal Ankles.

Ankle syndesmotic ligament injury is an important factor affecting clinical outcome after lower extremity injury with as little as 2 mm of syndesmotic displacement leading to worse clinical outcome. One important factor is the appropriate placement of clamps and fixation across the syndesmosis. When not ideally aligned, these can result in malalignment of the fibula in the incisura. This study sought to provide computer validation of using the center-center technique to identify an ideal centroid axis for placement of syndesmotic implants. Thirty computed tomography (CT) scans of patients from July 1, 2016, to June 30, 2018, with normal syndesmoses were evaluated. Center-center and centroid measurements were drawn and compared on the axial CT images at 10, 20, and 30 mm superior to the tibial plafond. Three observers recorded measurements for the same 50 patients in order to compare interobserver reliability. The difference between the centroid and center-center axis at each height level was a mean 0.4 degrees (range, 0.3-0.5 degrees). The center-center and centroid axis change by externally rotating as the height increases away from the tibial plafond with mean, 3 degrees (range, 0-6.1 degrees). Intraclass correlation coefficients (ICCs) were measured at 0.98, thus demonstrating excellent intraobserver and interobserver reliability on these measurements. The center-center technique can be used to identify the centroid axis within an acceptable degree of rotation at heights above the tibial plafond that are relevant to an operating surgeon placing syndesmotic fixation. Theoretically, this aligns the centroids of the fibula and tibia, which achieves the same ideal patient-specific alignment and raises the question as to the extent to which the centroid and center-center axes correlate in the general population. If present, a strong correlation has potentially high clinical importance when planning syndesmotic fixation.

Treatment of Acute Ankle Syndesmotic Injury by Syndesmotics Screw Fixation

Background: The distal tibiofibular syndesmosis is a connection between tibia and fibula that consists of the anterior tibiofibular ligament, the posterior tibiofibular ligament, the transverse ligament and the interosseous ligament. Syndesmotic ligament injuries are most often seen in combination with ankle fractures, but can occur in isolation as well. The term ‘isolated syndesmotic injury’ is used for the syndesmotic rupture without ankle fracture, although concomitant other injuries may be present. These isolated injuries, which are often accompanied by deltoid ligament injuries. Objective: To evaluate the efficiency of use of syndesmotic screw fixation in treatment of acute ankle syndesmotic injury. Patients and Methods: This Prospective study included twenty adult patients with recent ankle syndesmotic injury who were treated by syndesmotic screw at Al-Azhar university hospital and mansheyat El-bakry hospital, Cairo, Egypt. Those twenty patients prospectively followed up for 12 months with average of 9 months. The clinical outcomes were calculated according AOFAS score. Results: Those 20 patients prospectively followed up for an average of 9 months. Preoperative mean value for medial clear space (MCS) was 11.8±3.9 mm, tibiofibular clear space (TFCS) was 9.2±1.6 mm and tibiofibular overlap (TFO) was 2.2±4.7 mm. while the follow up mean MCS was 3.3±0.4 mm, TFCS was 3.2±0.4 mm and TFO was measured as 11.9±1.2 mm The mean AOFAS score was 97.0±3.8 (range 90–100). Conclusion: Reduction of the syndesmosis is essential for improving functional outcomes and avoiding posttraumatic osteoarthritis. It is important to intraoperatively stress all surgically treated ankle fractures to evaluate latent syndesmotic injury.

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

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

Does fracture obliquity in Weber B fibula fractures correlate with mortise instability?

BackgroundThe diagnosis of instability in the apparent, isolated distal fibula fracture can be challenging and often necessitates stress radiography. Danis & Weber classified lateral malleolar fractures based on the level of the fracture in relation to the syndesmosis. While Weber B fractures occur at the level of the syndesmosis, some such injuries present with a long, oblique pattern extending well above the syndesmosis. Given the well-established literature demonstrating that fractures above the syndesmosis correlate with a higher level of concomitant syndesmotic and deltoid ligament injury, we hypothesize that increased fracture obliquity, length and height of Weber B fibula fractures similarly correlates with increased mortise instability. MethodsAll patients with isolated Weber B fibula fractures who underwent gravity stress radiography met inclusion criteria. Fracture height was measured on mortise radiographs as: (1) the distance from the distal tip of the fibula to fracture apex, (2) the distance to the fracture apex as measured on a line drawn perpendicular to a line parallel to the plafond, (3) an angle subtended by a line drawn parallel to the plafond and a line drawn to the fracture apex and (4) a ratio of the absolute length as compared to fibular width. Results51 patients were included in the study. The group of 39 patients with stable ankles had a mean medial clear space of 3.12 ± 0.65 mm (range, 1.5 mm to 4.0 mm). The group of 12 patients with unstable ankles had a mean medial clear space of 6.29 ± 3.11 mm (range, 4.1 mm to 14.0 mm). These groups showed no significant difference in fracture angle (p = 0.93), fracture height from plafond (p = 0.49), fracture height from tip of fibula (p = 0.42), and as a ratio of absolute length to fibular width (p = 0.85). ConclusionIncreased fracture obliquity, length and height of Weber B fibula fractures did not correlate with a higher incidence of mortise instability. Despite the lack of positive correlation, future studies should continue to investigate and identify radiographic parameters of distal fibula fractures that are most predictive of instability.

Effect of CAM boot immobilization on weightbearing stability in syndesmotic injuries

Category: Trauma Introduction/Purpose: Ankle injuries are one of the most frequent traumas of the lower limb. They typically involve the lower lateral ligaments of the ankle, but the syndesmosis is also affected in up to 18% of cases. The degree of instability of syndesmotic joint depends on which ligaments are affected. Adequate management of syndesmotic injuries is crucial to avoid long term complications. The primary goal of our study was to evaluate the effect of simulated weightbearing on syndesmotic instability resulting from isolated AiTFL injury and from combined AiTFL/IOL injuries. The secondary goal was to evaluate the effect of a controlled ankle motion walking boot on syndesmosis stability following injury. We hypothesized that the CAM boot would prevent significant instability even in two ligaments injuries. Methods: Ten cadaveric specimens were dissected to expose the syndesmosis to create progressive iatrogenic syndesmosis ruptures. Uninjured syndesmoses were compared to isolated AiTFL and combined AiTFL/IOL ruptures. The specimens were fitted in a custom-made device to allow stabilization of the leg and apply a reproducible axial load (AL) of 750 N, equivalent to the weight of a 168-pound person. For each specimen and injury pattern, CT-scan images were obtained with and without AL, and with a CAM boot under AL. Distal tibio-fibular relationship was evaluated in three planes using a previously validated measurement system developed on CT. Wilcoxon tests for paired samples and non-parametric data were done to compare the different conditions. Results: For our first objective, when comparing ankles with isolated AiTFL to combined AiTFL/IOL rupture with and without AL, the only significant difference was an increase in internal rotation between the incisura and a line drawn in the axis of the fibula. Even with minimal statistical differences, it appears that axial loading does not impact syndesmotic stability apart from a slight increase in internal rotation with a single or two-ligament injury. As for our second end point, with the CAM orthopedic boot, no significant widening of the syndesmosis happened when either one or both ligaments were sectioned, in an axial loading state. We therefore confirmed our hypothesis that even with two syndesmotic ligament injuries, axial loading in a CAM boot does not affect distal tibio-fibular anatomy. Conclusion: This study reveals that weight bearing without rotational force does not affect the stability of the syndesmosis. Incomplete syndesmotic injuries can likely be treated with nonoperative treatment in a CAM boot and weight bearing as tolerated. Further clinical studies are needed to confirm these findings.

Arthroscopic Characterization of Syndesmotic Instability

Category: Arthroscopy, Sports, Trauma, Other, Syndesmosis Introduction/Purpose: Ankle arthroscopy is increasingly used to diagnose syndesmostic instability by visualizing the distal tibiofibular articulation and applying a lateral fibular stress. Precisely where in the incisura one should measure potential diastasis, however, remains unclear. The purpose of this study was to determine where within the incisura one should assess coronal plane instability in purely ligamentous syndesmotic injuries when performing a lateral hook stress test (LHT). Methods: Twenty-two above-knee cadaveric specimens underwent ankle arthroscopy, first with intact ligaments and thereafter after each sequential step of syndesmotic and deltoid ligament transection. At each step, a standard 100 N hook test was applied through a lateral incision 5 cm proximal to the ankle joint and the coronal plane diastasis in the stressed and unstressed states were measured at both anterior and posterior third of the distal tibiofibular joint using calibrated probes ranged from 0.1 to 6.0 mm, with 0.1 mm of increments. Results: Anterior third diastasis did not change significantly when applying a LHT, neither in the intact state nor after any stage of ligament transection (P values ranging from p=0.61 to p=0.94). In contrast, posterior third diastasis increased significantly by applying stress at the intact state at the following stages of transection: posterior-inferior tibiofibular ligament (PITFL), PITFL plus interosseous ligament, all syndesmosis ligaments, and all syndesmosis ligaments plus superficial and deep deltoid ligament (P values ranging p=0.001 to p=0.031). Interobserver agreement was substantial (ICC = 0.81; 95% confidence interval, 0.44-0.92), and moderate (ICC = 0.73; 95% confidence interval, 0.36-0.87) for anterior and posterior third diastasis measurements, respectively. Conclusion: Syndesmotic ligament injury results in coronal plane instability of the distal tibiofibular articulation that is readily identified arthroscopically with a LHT and when measured in the posterior third of the incisura. Measurement at the anterior third of the incisura may miss such injuries.

Invisible Injuries in Ankle Fractures

Category: Ankle, Trauma, Biomechanical Introduction/Purpose: Ankle fractures are often associated with ligamentous injuries of the distal tibiofibular syndesmosis, the deltoid ligament and are predictive of ankle instability, early joint degeneration and long-term ankle dysfunction. Detection of ligamentous injuries and the need for treatment remain subject of ongoing debate. In the classic article of Boden it was made clear that injuries of the syndesmotic ligaments were of no importance in the absence of a deltoid ligament rupture. Even in the presence of a deltoid ligament rupture, the interosseous membrane withstood lateralization of the fibula in fractures up to 4.5 mm above the ankle joint. Generally, syndesmotic ligamentous injuries are treated operatively by temporary fixation performed with positioning screws. But do syndesmotic injuries need to be treated operatively at all? Methods: The purpose of this biomechanical cadaveric study was to investigate the relative movements of the tibia and fibula, under normal physiological conditions and after sequential sectioning of the syndesmotic ligaments. Ten fresh-frozen below-knee human cadaveric specimens were tested under normal physiological loading conditions. Axial loads of 50 Newton (N) and 700 N were provided in an intact state and after sequential sectioning of the following ligaments: anterior-inferior tibiofibular (AITFL), posterior-inferior tibiofibular (PITFL), interosseous (IOL), and whole deltoid (DL). In each condition the specimens were tested in neutral position, 10 degrees of dorsiflexion, 30 degrees of plantar flexion, 10 degrees of inversion, 5 degrees of eversion, and externally rotated up to 10 Nm torque. Finally, after sectioning of the deltoid ligament, we triangulated Boden’s classic findings with modern instruments. We hypothesized that only after sectioning of the deltoid ligament; the lateralization of the talus will push the fibula away from the tibia. Results: During dorsiflexion and external rotation the ankle syndesmosis widened, and the fibula externally rotated after sequential sectioning of the syndesmotic ligaments. After the AITFL was sectioned the fibula starts rotating externally. However, the external rotation of the fibula significantly reduced when the external rotation torque was combined with axial loading up to 700 N as compared to the external rotation torque alone. The most relative moments between the tibia and fibula were observed after the deltoid ligament was sectioned. Conclusion: Significant increases in movements of the fibula relative to the tibia occur when an external rotation torque is provided. However, axial pressure seemed to limit external rotation because of the bony congruence of the tibiotalar surface. The AITFL is necessary to prevent the fibula to rotate externally when the foot is rotating externally. The deltoid ligament is the main stabilizer of the ankle mortise.

Determination of The Most Appropriate Surgical Treatment in Syn-desmotic Injury of Ankle Joint: Application of Taguchi Method

Background:Ankle injuries are more frequently observed in youth and athletes, and may lead to permanent disabilities if not treated properly. Approximately 10% of ankle injuries are associated with syndesmotic ligament injuries and fixation with screw is frequently applied as surgical treatment. The present study we aimed to determine the most proper model and model parameters by evaluating the minimum equivalent von Mises stress value developed in syndesmotic fixation of the ankle. Methods: By modeling the normal lower extremity in a healthy subject via the finite element analysis (FEA) method, we compared stress developed in a normal standing position in the models of syndesmotic injuries approached by frequently used cortical screws of various lengths and diameters, and by considering the number of screws and localization of fixation. Tibia, fibula, talus, and calcaneus were modeled as a three dimensional (3D) solid model via images of computerized tomography (CT), using the MIMICS program (version 10.01). The obtained 3D model was saved in the MIMICS program in STL (steriolithography) format, and transferred to the Geomagic Studio (version 10) program. Essential corrections were applied to the bones with the aid of the Geomagic program. The model of lower extremity designed was transferred to the Solidworks (version 2014) program in IGES (Initial Graphics Exchange Specification) format, and thus the meniscus and cartilage were modeled. Tensions that developed in the ankle were calculated after forming a mesh pattern via the ANSYS Workbench (version 15.0) software. Results: Sixteen different models obtained were analyzed by the Taguchi method, and the most appropriate models and model parameters were indicated by determining the minimum equivalent von Mises stress value. Conclusion: Screw diameter was determined to be the most important parameter. When 16 different models were considered, a screw diameter of 4.5 mm and three-cortex fixation with two screws parallel to the tibial joint surface were found to produce the most convenient model.DOI: http://dx.doi.org/10.5755/j01.mech.23.1.14024

Arthroscopically Assisted Open Reduction–Internal Fixation of Ankle Fractures: Significance of the Arthroscopic Ankle Drive-through Sign

Standalone open reduction–internal fixation (ORIF) of unstable ankle fractures is the current standard of care. Intraoperative stress radiographs are useful for assessing the extent of ligamentous disruption, but arthroscopic visualization has been shown to be more accurate. Concomitant arthroscopy at the time of ankle fracture ORIF is useful for accurately diagnosing and managing syndesmotic and deltoid ligament injuries. The arthroscopic ankle drive-through sign is characterized by the ability to pass a 2.9-mm shaver (Smith & Nephew, Andover, MA) easily through the medial ankle gutter during arthroscopy, which is not usually possible with both an intact deltoid ligament and syndesmosis. This arthroscopic maneuver indicates instability after ankle reduction and fixation and is predictive of the need for further stabilization. Furthermore, when this sign remains positive after fracture fixation, it may guide the surgeon to further evaluate the adequacy of fixation for the possible need for further fixation of the syndesmosis or deltoid. We present the case of an ankle fracture managed with arthroscopy-assisted ORIF and describe the clinical utility of the arthroscopic ankle drive-through sign.

Plantar talar head contusions and osteochondral fractures: associated findings on ankle MRI and proposed mechanism of injury

To evaluate the significance of plantar talar head injury (PTHI) in predicting osseous and soft tissue injuries on ankle MRI. The IRB approved this HIPAA-compliant retrospective study. The study group consisted of 41 ankle MRIs with PTHI that occurred at our institution over a 5 ½ year period. Eighty MRIs with bone injuries in other locations matched for age, time interval since injury, and gender formed a control group. Injuries to the following structures were recorded: medial malleolus, lateral malleolus/distal fibula, posterior malleolus, talus, calcaneus, navicular, cuboid, lateral, medial and syndesmotic ligaments, spring ligament complex, and extensor digitorum brevis (EDB) muscle. Twenty separate logistic regressions determined which injuries PTHI predicted, using the Holm procedure to control for family-wise alpha at 0.05. PTHI strongly predicted the occurrence of injuries involving the anterior process of the calcaneus [24% of cases, odds ratio (OR) 12.66], plantar components of the spring ligament (27%, OR 9.43), calcaneal origin of the EDB and attachment of the dorsolateral calcaneocuboid ligament (22%, OR 7.22), cuboid (51%, OR 6.58), EDB (27%, OR 5.49), anteromedial talus (66%, OR 4.78), and posteromedial talus (49%, OR 4.48). PTHI strongly predicted lack of occurrence of syndesmotic ligament injury (OR 19.6). The PTHI group had a high incidence of lateral ligamentous injury (78%), but not significantly different from the control group (53%). PTHI is strongly associated with injury involving the transverse tarsal joint complex. We hypothesize it results from talo-cuboid and/or talo-calcaneal impaction from a supination injury of the foot and ankle.

Diaphyseal tibiofibular synostosis in professional athletes: Report of 2 cases

Anterior leg pain is common in professional athletes and tibiofibular synostosis is reported to be a rare cause of anterior compartment pain or ankle pain related to sports activities. The management and appropriate treatment of this condition in professional athletes is controversial and the literature on the topic is sparse. Distal synostosis is usually related to ankle sprain and syndesmotic ligament injury, and proximal synostosis has been linked to leg length discrepancy and exostosis. Mid-shaft synostosis is even less common than proximal and distal forms. We present the treatment of mid-shaft tibiofibular synostosis in 2 cases of professional athletes (soccer and basketball player), along with a review of the literature. When diaphyseal synostosis is diagnosed, first-line conservative treatment, including ultrasound-guided steroid injection is recommended. However, if it does not respond to conservative management, surgical resection may be indicated to relieve symptoms.

Ligamentous Injuries and the Risk of Associated Tissue Damage in Acute Ankle Sprains in Athletes

Background: Ankle joint injuries are extremely common sports injuries, with the anterior talofibular ligament involved in the majority of ankle sprains. There have been only a few large magnetic resonance imaging (MRI) studies on associated structural injuries after ankle sprains. Purpose: To describe the injury pattern in athletes who were referred to MRI for the assessment of an acute ankle sprain and to assess the risk of associated traumatic tissue damage including lateral and syndesmotic ligament involvement. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 261 ankle MRI scans of athletes with acute ankle sprains were evaluated for: lateral and syndesmotic ligament injury; concomitant injuries to the deltoid and spring ligaments and sinus tarsi; peroneal, flexor, and extensor retinacula and tendons; traumatic and nontraumatic osteochondral and osseous changes; and joint effusion. Patients were on average 22.5 years old, and the average time from injury to MRI was 5.7 days. Six exclusive injury patterns were defined based on lateral and syndesmotic ligament involvement. The risk for associated injuries was assessed by logistic regression using ankles with no or only low-grade lateral ligament injuries and no syndesmotic ligament damage as the reference. Results: With regard to the injury pattern, there were 103 ankles (39.5%) with complete anterior talofibular ligament disruption and no syndesmotic injury, and 53 ankles (20.3%) had a syndesmotic injury with or without lateral ligament damage. Acute osteochondral lesions of the lateral talar dome were seen in 20 ankles (7.7%). The percentage of chronic lateral osteochondral lesions was 1.1%. The risk for talar bone contusions increased more than 3-fold for ankles with complete lateral ligament ruptures (adjusted odds ratio [aOR], 3.43; 95% CI, 1.72-6.85) but not for ankles with syndesmotic involvement. The risk for associated deltoid ligament injuries increased for ankles with complete lateral ligament injuries (aOR, 4.04; 95% CI, 1.99-8.22) compared with patients with no or only low-grade lateral ligament injuries. Conclusion: About 20% of athletes referred for MRI after suffering an acute ankle sprain had evidence of a syndesmotic injury regardless of lateral ligament involvement, while more than half had evidence of any lateral ligament injury without syndesmotic involvement. Concomitant talar osseous and deltoid ligament injuries are common.

Magnetic Resonance Imaging as a Predictor of Return to Play Following Syndesmosis (High) Ankle Sprains in Professional Football Players

Background:Syndesmosis ankle sprains cause greater disability and longer duration of recovery than lateral ankle sprains.Objective:To describe the severity of syndesmosis sprains using several accepted magnetic resonance imaging (MRI) criteria and to assess the interrater reliability of diagnosing syndesmosis injury using these same criteria in professional American football players.Hypothesis:There is a high degree of interrater reliability of MRI findings in American football players with syndesmosis ankle sprains. These radiographic findings will correlate with time lost to injury, indicating severity of the sprain.Study Design:Uncontrolled retrospective review.Methods:Player demographics and time lost to play were recorded among professional football players who had sustained a syndesmosis ankle sprain and underwent standardized ankle MRI. Each image was independently read by 3 blinded musculoskeletal radiologists.Results:Seventeen players met study criteria. There was almost perfect agreement among the radiologists for diagnosing injury to the syndesmotic membrane; substantial agreement for diagnosing injury to the posterior inferior tibiofibular ligament (PITFL) and in determining the proximal extent of syndesmotic edema/injury; but only fair agreement for diagnosing injury to the anterior inferior tibiofibular ligament and in determining the width of syndesmotic separation. There was a significant correlation between the width of syndesmotic separation and time lost, but no significant correlation between individual syndesmotic ligament injury or proximal extent of syndesmotic edema/injury and time lost.Conclusion:While ankle MRI can identify syndesmotic disruption with a high degree of interobserver agreement, no association was demonstrated between the extent of injury on MRI and the time to return to play following a high ankle sprain.Clinical Relevance:In athletes with suspected high ankle sprains, MRI may help confirm diagnosis or suggest alternative diagnoses when the syndesmotic supporting structures are intact. However, the severity of ligamentous and syndesmotic disruption on MRI cannot help predict recovery times.

Syndesmosis and deltoid ligament injuries in the athlete

Injury to the syndesmosis and deltoid ligament is less common than lateral ligament trauma but can lead to significant time away from sport and prolonged rehabilitation. This literature review will discuss both syndesmotic and deltoid ligament injuries without fracture in the professional athlete. A narrative review was performed using PUBMED, OVID, MEDLINE and EMBASE using the key words syndesmosis, injury, deltoid, ankle ligaments, and athlete. Articles related to the topic were included and reviewed. The incidence of syndesmotic injury ranges from 1 to 18 % of ankle sprains. This may be underreported and is an often missed injury as clinical examination is generally not specific. Both MRI and ultrasonography have high sensitivities and specificities in diagnosing injury. Arthroscopy may confirm the diagnosis, and associated intra-articular pathology can be treated at the same time as surgical stabilization. Significant deltoid ligament injury in isolation is rare, there is usually associated trauma. Major disruption of both deep and superficial parts can lead to ankle dysfunction. Repair of the ligament following ankle fracture is not necessary, but there is little literature to guide the management of deltoid ruptures in isolation or in association with syndesmotic and lateral ligament injuries in the professional athlete. Management of syndesmotic injury is determined by the grade and associated injury around the ankle. Grade I injuries are treated non-surgically in a boot with a period of non-weight bearing. Treatment of Grade II and III injuries is controversial with little literature to guide management. Athletes may return to training and play sooner if the syndesmosis is surgically stabilized. For deltoid ligament injury, grade I and II sprains should be treated non-operatively. Unstable grade III injuries with associated injury to the lateral ligaments or the syndesmosis may benefit from operative repair.

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.

Arthroscopic findings in Maisonneuve fractures

BackgroundA Maisonneuve fracture consists of a proximal fibular fracture with associated syndesmotic ligament disruption and injury to the medial ankle structures. The treatment outcome is good in most cases, although poor results have also been reported. The purpose of this study was to investigate intra-articular lesions in Maisonneuve fractures. MethodsThe subjects consisted of four patients (four ankle joints) who had suffered a Maisonneuve fracture and had undergone surgical treatment between June 2005 and November 2005. The mean age was 24.2 years. At the time of surgery, we performed ankle arthroscopy and determined the presence of tibiofibular syndesmosis disruption, cartilaginous damage, and ligament damage. Lesions of the articular cartilage were graded by depth as determined by inspection and probing. ResultsAll four of the cases had cartilaginous damage to the medial section of the talar dome. Lateral lesions were not observed. Chondral debris and hemarthrosis were noted in virtually all cases, and each ankle had a tear on the anterior inferior tibiofibular ligament and interosseous tibiofibular ligament. No patients had a tear of the posterior inferior tibiofibular ligament. ConclusionsArthroscopy was useful in identifying associated intra-articular lesions in Maisonneuve fractures.