Morphology of Fibular Incisura is a Deciding Factor Between Posterior Malleolus Avulsion Fracture or Syndesmotic Ligament Injury in Ankle Fractures.

The bone anatomy of tibiofibular syndesmosis has been a topic of interest. Fibular incisura morphology has been analyzed on cadaver specimens, plain radiographs, or CT images. The aim of this study is to examine the effects of fibula incisura features and fibula morphology in ankle injuries, especially involving posterior malleolus and posteroinferior tibiofibular ligament injuries. From 2017 through 2022, A total of 59 patients with isolated lateral malleolar fracture, Mason-Malloy type 1 posterior malleolar fracture, syndesmosis injury in those without posterior malleolar fracture, supination external rotation type 3 injuries according to Lauge-Hansen classification, and preoperative bilateral ankle computed tomography images were included in the study. Fibula morphologies and syndesmosis measurements were made from preoperative computed tomography images using axial CT images from 1 cm proximal to the tibial plafond. The diagnosis of posterior malleolar fractures was made using the CT classification system of Mason and Malloy, and the diagnosis of syndesmosis injury was made with a cotton test during surgery. Age, gender, fractured side, incisura type, incisor depth, width, anterior and posterior facet lengths, incisor version (antevert-retrovert), the angle between the anterior and posterior facets, and fibula type were recorded. There was a statistically significant difference between the groups in posterior facet length and incisura width. Morphological features of fibular incisura may be the determinant of PITFL injury or PMA injury in fibular fractures caused by an external rotation mechanism.

[Conservative treatment of supination and external rotation for type â ¢ and â £ankle fracture by bone setting].

OBJECTIVE: To explore curative effect of conservative treatment of supination-lateral rotation (SER) with type Ⅲ and Ⅳ ankle fracture by bone setting technique. METHODS: From January 2017 to December 2019, 64 patients diagnosed with SER with type Ⅲ and Ⅳ ankle fracture were treated with manipulative reduction and conservative treatment (manipulation group) and surgical treatment with open reduction and internal fixation (operation group), 32 patients in each group. In manipulation group, there were 17 males and 15 females, aged from 15 to 79 years old with an average of (51.42±13.68) years old;according to Lauge-Hansen classification, there were 8 patients with supination external rotation type Ⅲ and 24 patients with type Ⅳ. In operation group, there were 13 males and 19 females, aged from 18 to 76 years old with an average of (47.36±15.02) years old;7 patients with type Ⅲ and 25 patients with type Ⅳ. Displacement of ankle fracture was measured by Digimizer software, and compared before treatment, 3 and 12 months after treatment between two groups. Lateral medial malleolus displacement, lateral medial malleolus displacement, lateral malleolus displacement, lateral malleolus displacement, lateral malleolus contraction displacement and posterior malleolus displacement were measured and compared between two groups. Mazur score was used to evaluate ankle joint function. RESULTS: All patients were followed up from 12 to 36 months with an average of (17.16±9.36) months. There were statistical differences in lateral medial malleolus displacement, lateral medial malleolus displacement, lateral malleolus displacement, lateral malleolus displacement, lateral malleolus contraction displacement and posterior malleolus displacement in manipulation group before and after reduction(P<0.05). Compared with operation group, there were no statistically significant differences in lateral malleolus shift, lateral malleolus shift, lateral malleolus contraction shift(P>0.05), while there were statistically significant differences in lateral malleolus shift, posterior malleolus shift up and down (P<0.05). Mazur scores of ankle joint at 3 months after treatment in manipulation group and operation group were 68.84±13.08 and 82.53±7.31, respectively, and had statistical differences(P<0.05), while there was no difference in evaluation of clnical effect(P>0.05). There were no differences in Mazur score and evaluation of clnical effect between two groups at 12 months after treatment (P>0.05). CONCLUSION: Bone setting technique could effectively correct lateral displacement of medial malleolus, lateral displacement of medial malleolus, lateral displacement of lateral malleolus and lateral contraction displacement of lateral malleolus in supination lateral rotation type Ⅲ and Ⅳ ankle fracture, and has good long-term clinical effect, which could avoid operation for some patients and restore ankle function after fracture.

Lack of Displacement of the Fibula Is Not a Confirmation of Ankle Stability in Supination External Pattern Ankle Fractures.

OBJECTIVES: To evaluate and compare radiographic findings in supination external (SE)2 injuries versus stress (+) SE4 injuries. DESIGN: Retrospective. SETTING: Academic Level 1 trauma center. PATIENTS: The study included 350 skeletally mature patients at a single Level 1 trauma center who presented with an isolated, Lauge-Hansen type supination-external rotation pattern, Weber B lateral malleolar fracture, OTA/AO 44-B. RESULTS: We reviewed 350 patients (185 men and 165 women), 18-95 years of age (avg 45), with isolated SE pattern lateral malleolar fractures. One hundred nine had SE4 injuries [medial clear space (MCS) = 8.3 mm]. Two hundred forty-one ankles were stressed; 164 were unstable and 77 were stable (SE2). Avg MCS at presentation and on stress radiographs was 3.59 mm for the SE2 (no widening) and 3.86 mm and 5.94 mm for the stress (+) SE4 group, respectively. The fibular displacement for the SE2, stress (+) SE4, and SE4 groups was 1.5 (0-4.5), 3.5 (0-6.6), and 4.1 (0-30.5), respectively. Sixteen of the 77 (20%) SE2 and 24 of the 164 (15%) stress (+) SE4 fractures had no displacement of the fibula on the lateral view. Similarly, 53 of the 77 (68%) SE2 and 91 of the 164 (55%) stress (+) SE4 had ≤2 mm of fibular displacement Fibular displacement of ≤2 mm on the lateral radiograph corresponded with 0.69 sensitivity and only 0.37 positive predictive value for stable ankle mortise on stress examination. CONCLUSIONS: Previous work indicated that patients with an isolated SE pattern fibula fracture, a normal MCS, and ≤2 mm of fibular displacement on the lateral radiograph have a high rate of ankle stability, with a positive predictive value of approximately 97%. We were unable to confirm this finding because 15% of unstable ankles had 0 mm and 55% had ≤2 mm of fibular displacement. We conclude that stability may not be inferred from a lack of fibular displacement on the lateral view in this population of patients. If stability is to be determined, it must be tested irrespective of fibular displacement on the lateral radiograph. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Nailing the fibula: alternative or standard treatment for lateral malleolar fracture fixation? A broken paradigm.

PURPOSE: Despite the fact that open reduction and internal fixation with a plate, either non-locked or locked, is the standard of care for managing lateral malleolus fractures, intramedullary (IM) fixation of the fibula has been recently introduced as an alternative, mainly for some potential complicated situations. We hypothesized that almost all patterns of distal fibula fracture can be safely fixed with an IM device, with the potential benefit of providing biomechanical efficiency, but using a soft-tissue friendly implant. Here, we present a multicenter case series based on a proposed algorithm. PATIENTS AND METHODS: Sixty-nine consecutive patients were managed with fibular IM fixation for closed malleolar fractures. Twenty patients were managed by IM screw fixation and 49 by fibular nailing. Outcome was measured both according to the American Orthopaedic Foot and Ankle Society (AOFAS) score for ankle and hindfoot, and the time to bone union. RESULTS: The mean AOFAS for Group I was 99.35 ± 1.95 points and that for Group II was 89.30 ± 16.98 points. There were no significant differences between the fracture pattern, according to the Lauge-Hansen classification, and post-operative levels of pain and functional activity among patients in both groups (p > 0.05). All fractures healed uneventfully in both groups. The mean time to union for Group I was 8.15 weeks and for Group II was 8.25 weeks (p > 0.05). CONCLUSION: In this multicenter case series, intramedullary fixation for the lateral malleolus fracture presented itself as a viable and safe option for the treatment of almost all patterns of fibula fracture in adults. Overall, we were able to demonstrate the potential indications of the proposed algorithm for the choice of IM implant for the lateral malleolus fracture in terms of the Lauge-Hansen staged classification.

Core curriculum illustration: supination-external rotation trimalleolar fracture.

This is the 37th installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and on the use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at http://www.erad.org/page/CCIP_TOC .

Anatomic Feasibility of Distal Fibula Bicortical Screw Fixation With Lateral Neutralization Plating for Rotational Ankle Fractures.

A common technique for fixation of rotational fibular fractures is to use an interfragmentary compression screw with a laterally positioned neutralization plate. The objective of the present investigation was to examine the anatomic feasibility of distal fibula bicortical fixation within this plating technique. A specific screw insertion technique was performed through a laterally positioned one-third tubular plate on a consecutive series of 81 intact cadaveric ankle mortises. The most distal plate hole was drilled, aimed 10° posterior to the midline of the fibula. The second-most distal plate hole was drilled, aimed 25° superiorly. The specimens were then dissected, and the screw termini were physically examined for whether they had penetrated the articular cartilage of the ankle mortise. The length of the most distal bicortical screw measured a mean ± standard deviation of 20.44 ± 2.49 (range 14 to 26) mm, with an extra-articular terminus in 95.06% of specimens. The length of the second-most distal bicortical screw measured a mean ± standard deviation of 19.68 ± 3.02 (range 12 to 28) mm, with an extra-articular terminus in 100% of the specimens. The results of the present study provide evidence that bicortical distal fibular fixation in accordance with basic fixation principles is anatomically possible and feasible with a one-third tubular plate. This could potentially obviate the need for more expensive fixation options (i.e., locked plates or anatomically contoured plates) and fixation options that are biomechanically stable but potentially anatomically impeding (i.e., posterior antiglide plating).

Evaluation and Significance of Mortise Instability in Supination External Rotation Fibula Fractures: A Review Article.

Evaluation and management of ankle fractures has progressed in parallel to an evolving understanding of ankle stability. While stability of the mortise had historically been attributed to the lateral malleolus, Lauge-Hansen's contributions followed by multiple other investigations increased the emphasis on the significance of medial-sided injury in destabilizing the mortise. As the importance of the deltoid ligament has been elucidated, the means of assessing ligamentous incompetence and the prognostic significance of an unstable mortise continue to be defined. LEVEL OF EVIDENCE: Level V, expert opinion.

[Anterior dislocation of the fibula resulting from surgical malreduction: a case report].

Ankle joint fracture is one of the most common types of fracture. There are many researches on the injury mechanism, treatment principles and surgical techniques. A type of injury which combines posterior dislocation of fibula, known as the Bosworth injury, is relatively rare. In 1947, Bosworth first described this type of injury as an unusual ankle fracture dislocation with fixed posterior fracture dislocation of the distal part of the fibula. In this type of fracture, the proximal fibular shaft fragment locks behind the tibialis posterior tubercle. This rare ankle fracture variant is often not recognized in initial radiographs and requires a computed tomographic (CT) scan for verification. But there are already many reports, discussing the injury mechanism, treatment principles and surgical techniques. However, there are few reports of anterior dislocation of the fibula, caused by either injury or surgery. The mechanism of the injury is still not clear. This article reports a case of anterior dislocation of the fibula. We report a patient with left ankle open fracture (Lauge-Hansen pronation-external rotation stage III, Gustilo IIIA). Open reduction and internal fixation was done in the initial surgery, but ended up with poor reduction, resulting in fibula anterior dislocation, anterior dislocation of talus and tibia fibular dislocation. The fibula was dislocated anteriorly of the tibia, which rarely happened. The patient suffered severe ankle joint dysfunction. The second operation took out the original internal fixation, reduced the fracture, and reset the internal fixation. The function of ankle joint was improved obviously after operation. But because of the initial injury and the two operations, the soft tissue around the fracture was greatly damaged. 6 months after the second operation, and the fracture still not healed, so the bone graft was carried out in the third surgery. Two months after the third surgery, the function of the ankle was significantly better than before, but the fracture healing was poor, which needed further review. Through this case, we understand the rare type of ankle fracture with anterior dislocation of the fibula, and recognize that the timing and quality of initial surgery has a great impact on the patient's prognosis and rehabilitation period.

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.

Osteological, biomolecular and geochemical examination of an early anglo-saxon case of lepromatous leprosy.

We have examined a 5th to 6th century inhumation from Great Chesterford, Essex, UK. The incomplete remains are those of a young male, aged around 21-35 years at death. The remains show osteological evidence of lepromatous leprosy (LL) and this was confirmed by lipid biomarker analysis and ancient DNA (aDNA) analysis, which provided evidence for both multi-copy and single copy loci from the Mycobacterium leprae genome. Genotyping showed the strain belonged to the 3I lineage, but the Great Chesterford isolate appeared to be ancestral to 3I strains found in later medieval cases in southern Britain and also continental Europe. While a number of contemporaneous cases exist, at present, this case of leprosy is the earliest radiocarbon dated case in Britain confirmed by both aDNA and lipid biomarkers. Importantly, Strontium and Oxygen isotope analysis suggest that the individual is likely to have originated from outside Britain. This potentially sheds light on the origins of the strain in Britain and its subsequent spread to other parts of the world, including the Americas where the 3I lineage of M. leprae is still found in some southern states of America.

A prospective randomised study comparing TightRope and syndesmotic screw fixation for accuracy and maintenance of syndesmotic reduction assessed with bilateral computed tomography.

BACKGROUND: The accuracy and maintenance of syndesmosis reduction are essential when treating ankle fractures with accompanying syndesmosis injuries. The primary aim of this study was to compare syndesmosis screw and TightRope fixation in terms of accuracy and maintenance of syndesmosis reduction using bilateral computed tomography (CT). STUDY DESIGN: Single centre, prospective randomised controlled clinical trial; Level of evidence 1. METHODS: This study (ClinicalTrials.gov, NCT01742650) compared fixation with TightRope(®) (Arthrex, Naples, FL, USA) or with one 3.5-mm tricortical trans-syndesmotic screw in terms of accuracy and maintenance of syndesmosis reduction in Lauge-Hansen pronation external rotation, Weber C-type ankle fractures with associated syndesmosis injury. Twenty-one patients were randomised to TightRope fixation and 22 to syndesmotic screw fixation. Syndesmosis reduction was assessed using bilateral CT intraoperatively or postoperatively, and also at least 2 years after surgery. Functional outcomes and quality of life were assessed using the Olerud-Molander score, a 100-mm Visual Analogue Scale, the Foot and Ankle Outcome Score, and the RAND 36-Item Health Survey. Grade of osteoarthritis was qualified with follow-up cone-beam CT. RESULTS: According to surgeons' assessment from intraoperative CT, screw fixation resulted in syndesmosis malreduction in one case whereas seven syndesmosis were considered malreduced when TightRope was used. However, open exploration and postoperative CT of these seven cases revealed that syndesmosis was well reduced if the ankle was supported at 90˚. Retrospective analysis of the intra- and post-operative CT by a radiologist showed that one patient in each group had incongruent syndesmosis. Follow-up CT identified three patients with malreduced syndesmosis in the syndesmotic screw fixation group, whereas malreduction was seen in one patient in the TightRope group (P = 0.33). Functional scores and the incidence of osteoarthritis showed no significant difference between groups. CONCLUSION: Syndesmotic screw and TightRope had similar postoperative malreduction rates. However, intraoperative CT scanning of ankles with TightRope fixation was misleading due to dynamic nature of the fixation. After at least 2 years of follow-up, malreduction rates may slightly increase when using trans-syndesmotic screw fixation, but reduction was well maintained when fixed with TightRope. Neither the incidence of ankle joint osteoarthritis nor functional outcome significantly differed between the fixation methods.

Maisonneuve-hyperplantarflexion variant ankle fracture.

Maisonneuve fractures are rare ankle injuries, accounting for up to 7% of all ankle fractures. They consist of a proximal third fibula fracture, syndesmotic disruption, and medial ankle injury (either a deltoid ligament disruption or a medial malleolus fracture), and are often successfully managed with nonoperative treatment of the proximal fibula fracture and open reduction and internal fixation (ORIF) of the medial ankle injury and syndesmotic disruption. The hyperplantarflexion variant ankle fracture comprises approximately 7% of all ankle fractures and features dual posterior tibial lip fractures featuring a posterolateral fragment and a posteromedial fragment. Good functional results have been reported in the literature after ORIF of both the posterolateral and posteromedial fragments of this variant fracture that is not described by the Lauge-Hansen classification. In this report, the authors present the unique case of an isolated ankle fracture demonstrating characteristics of both a Maisonneuve fracture and a hyperplantarflexion variant ankle fracture. They also highlight the diagnostic imaging characteristics, including magnetic resonance imaging (MRI) and preoperative radiograph findings, surgical treatment, and postoperative clinical outcome for this patient with a Maisonneuve-hyperplantarflexion variant ankle fracture. To the authors' knowledge, this unique fracture pattern has not been reported previously in the literature. The authors conclude that although good results were seen postoperatively in this case, the importance of ORIF of both the posteromedial and posterolateral fragments of variant fractures cannot be overstated. They also found MRI to be a particularly helpful adjunct in formulating the correct diagnosis and treatment plan.

Evaluation of Lauge-Hansen designation of Weber C fractures.

Associations between Weber C ankle fractures and pronation external rotation (PER) injuries of the Lauge-Hansen classification have often been incorrectly correlated. The purpose of the present study was to evaluate the Lauge-Hansen designation of Weber C fractures by establishing the proportion of Weber C fractures that are supination external rotation (SER), supination adduction (SA), pronation abduction (PA), PER, and hyperplantarflexion variant fractures. A clinical database of operative ankle fractures treated by the senior author (D.G.L.) was reviewed. The inclusion criteria were patient age older than 16 years, preoperative ankle radiographs, and Weber C fracture designation. A total of 132 patients met the inclusion criteria, and the proportion of PA, PER, SER, SA, and variant fractures among the Weber C fractures was analyzed. PA fractures accounted for 0.8% (n = 1), PER fractures 56.8% (n = 75), SER fractures 35.6% (n = 47), and hyperplantarflexion variant fractures 6.8% (n = 9) of the 132 Weber C fractures. Patients with Weber C-PER fractures were more commonly male (p = .005) and younger (p = .003) and demonstrated a greater fibular fracture height (p < .001) than those with Weber C-SER and Weber C-variant fractures. Our study quantitatively demonstrated that not all Weber C fractures occur secondary to pronation injuries. This distinction is important, because all pronation injuries will demonstrate medial ankle injury, but SER and variant fractures might not. We therefore recommend careful evaluation of the fibular fracture characteristics, including the direction of fracture propagation and the distance from the tibial plafond, when classifying Weber C fractures using the Lauge-Hansen system, because correct classification is vital in preparation for appropriate operative treatment.

Comparison of radiographic stress tests for syndesmotic instability of supination-external rotation ankle fractures: a cadaveric study.

OBJECTIVE: According to the classification of Lauge-Hansen, supination-external rotation IV (OTA 44-B) injuries should not have syndesmotic instability; yet, several studies have suggested disruption is present in up to 40% of these injuries based on stress tests. In this study, we examine various stress radiographic parameters in a cadaver model of supination-external rotation IV equivalent injury. We hypothesize that external rotation stress testing and widening of the medial clear space do not always represent syndesmotic instability. Rather, the better predictor of syndesmotic instability will be an increased tibia-fibula clear space with the lateral stress test. METHODS: Eleven fresh frozen human lower limbs were each secured into a custom frame. External rotation stress test was performed by applying an external moment of 7.5 Nm, and lateral stress test was performed by applying 100 N lateral pull at the distal fibula. True mortise radiographs were taken of intact ankles and while performing external rotation and lateral stress tests at each stage of sequentially sectioning the ankle ligaments. The deltoid ligament was sectioned first, then anterior-inferior tibiofibular ligament, posterior-inferior tibiofibular ligament, and interosseous membrane. Tibiofibular clear space and medial clear space were measured on each radiograph. RESULTS: External rotation stress test produced significant medial clear space widening when the deltoid ligaments were sectioned (P < 0.05). Lateral stress test produced no significant widening of the tibiofibular clear space until interosseous membranes were sectioned (P < 0.05). CONCLUSIONS: Lateral stress test with widening of the tibiofibular clear space is the preferred indicator of syndesmotic instability. The external rotation stress is a poor indicator of syndesmotic injury in the setting of deltoid ligament injury.

[Effectiveness of open reduction and internal fixation for Bosworth fracture].

OBJECTIVE: To explore the operative methods and effectiveness of open reduction and internal fixation for Bosworth fracture. METHODS: Between January 2005 and January 2012, 6 patients with Bosworth fractures caused by sprain were treated. There were 4 males and 2 females with an average age of 45.8 years (range, 24-73 years). The time from injury to operation was 1-5 days (mean, 1.8 days). They were all closed fractures. According to Lauge-Hansen classification, 6 cases were classified as supination-external rotation type. The surgical treatments included open reduction and internal fixation by plate and screws. RESULTS: Infection occurred in 1 case and was cured after dressing changing; primary healing of incision was obtained in the other 5 cases. Six patients were followed up 15 months on average (range, 12-24 months). The X-ray films showed fracture healing in all cases, with an average healing time of 9.5 weeks (range, 8-13 weeks). No loosening or breaking of internal fixator was observed during follow-up. The average full load-walking time was 12 weeks (range, 10-17 weeks). According to the ankle and hindfoot scale of American Orthopaedic Foot and Ankle Society (AOFAS), the average score was 89.5 (range, 81-94). CONCLUSION: For Bosworth fractures, good results can be achieved by early diagnosis, open reduction and internal fixation.

Adult-type bimalleolar ankle fracture in children: report of two cases.

UNLABELLED: Ankle fractures patterns in children may vary depending on the maturity of the distal tibial and fibular physis. Bimalleolar ankle fracture is an exceedingly rare fracture pattern in children and has been reported once in the current English literature. Two further adolescents with bimalleolar ankle fracture are reported. Although these fractures are rare, surgeons should be aware of these atypical fracture patterns. Herein, the underlying physiology and the mechanism of injury of ankle fractures in children are discussed. LEVEL OF EVIDENCE: Therapeutic, Level IV, Case study.

Simplified diagnostic algorithm for Lauge-Hansen classification of ankle injuries.

Ankle injuries occur in a predictable sequence, allowing a logical understanding of their classification once the injury mechanism is recognized. The Lauge-Hansen classification system was developed on the basis of the mechanism of trauma and is useful for guiding treatment. Three radiographic views of the ankle (anteroposterior, mortise, and lateral) are necessary to classify an injury with the Lauge-Hansen system. Two additional criteria are also necessary: the position of the foot at the time of injury and the direction of the deforming force. Because understanding the mechanism of trauma is fundamental to classifying the injury, three-dimensional movies were assembled for each classification, showing the sequence of ligament rupture and bone fractures that occurs with each type of traumatic mechanism. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.322115017/-/DC1.

Tibiofibular syndesmosis in acute ankle fractures: additional value of an oblique MR image plane.

OBJECTIVE: To evaluate the additional value of a 45° oblique MRI scan plane for assessing the anterior and posterior distal tibiofibular syndesmotic ligaments in patients with an acute ankle fracture. MATERIALS AND METHODS: Prospectively, data were collected for 44 consecutive patients with an acute ankle fracture who underwent a radiograph (AP, lateral, and mortise view) as well as an MRI in both the standard three orthogonal planes and in an additional 45° oblique plane. The fractures on the radiographs were classified according to Lauge-Hansen (LH). The anterior (ATIFL) and posterior (PTIFL) distal tibiofibular ligaments, as well as the presence of a bony avulsion in both the axial and oblique planes was evaluated on MRI. MRI findings regarding syndesmotic injury in the axial and oblique planes were compared to syndesmotic injury predicted by LH. Kappa and the agreement score were calculated to determine the interobserver agreement. The Wilcoxon signed rank test and McNemar's test were used to compare the two scan planes. RESULTS: The interobserver agreement (κ) and agreement score [AS (%)] regarding injury of the ATIFL and PTIFL and the presence of a fibular or tibial avulsion fracture were good to excellent in both the axial and oblique image planes (κ 0.61-0.92, AS 84-95%). For both ligaments the oblique image plane indicated significantly less injury than the axial plane (p < 0.001). There was no significant difference in detection of an avulsion fracture in the axial or oblique plane, neither anteriorly (p = 0.50) nor posteriorly (p = 1.00). With syndesmotic injury as predicted by LH as comparison, the specificity in the oblique MR plane increased for both anterior (to 86% from 7%) and posterior (to 86% from 48%) syndesmotic injury when compared to the axial plane. CONCLUSION: Our results show the additional value of an 45° oblique MR image plane for detection of injury of the anterior and posterior distal tibiofibular syndesmoses in acute ankle fractures. Findings of syndesmotic injury in the oblique MRI plane were closer to the diagnosis as assumed by the Lauge-Hansen classification than in the axial plane. With more accurate information, the surgeon can better decide when to stabilize syndesmotic injury in acute ankle fractures.

A contoured locking plate for distal fibular fractures in osteoporotic bone: a biomechanical cadaver study.

OBJECTIVE: Fixation of ankle fractures in elderly patients is associated with reduced stability conditioned by osteoporotic bone. Therefore, fixation with implants providing improved biomechanical features could allow a more functional treatment, diminish implant failure and avoid consequences of immobilisation. MATERIALS AND METHODS: In the actual study, we evaluated a lateral conventional contoured plate with a locking contoured plate stabilising experimentally induced distal fibular fractures in human cadavers from elderly. Ankle fractures were induced by the supination-external rotation mechanism according to Lauge-Hansen. Stage II fractures (AO 44-B1) were fixed with the 2 contoured plates and a torque to failure test was performed. Bone mineral density (BMD) was measured by quantitative computed tomography to correlate the parameters of the biomechanical experiments with bone quality. RESULTS: The locking plate showed a higher torque to failure, angle at failure, and maximal torque compared to the conventional plate. In contrast to the nonlocking system, fixation with the locking plate was independent of BMD. CONCLUSION: Fixation of distal fibular fractures in osteoporotic bone with the contoured locking plate may be advantageous as compared to the nonlocking contoured plate. The locking plate with improved biomechanical attributes may allow a more functional treatment, reduce complications and consequences of immobilisation.

[Supination external rotation lesions of the ankle joint in osteoporotic lower leg specimens. Experimental induction and review of the literature]. / Die Supinations-Eversions-Verletzung des OSG in osteoporotischen Unterschenkelpräparaten. Experimentelle Induktion und Literaturübersicht.

BACKGROUND: Knowledge of the pathomechanism and the detailed extent of ankle joint lesions determines adequate therapy and success of treatment. MATERIAL AND METHODS: Supination external rotation lesions were induced in 29 human cadavera with a testing apparatus; 27 of these specimens were from elderly women. Bone mineral density was measured. The literature review includes experimental studies of this fracture entity. RESULTS: We induced stage II in 42%; applying an additional lateral force on the fibula raised the incidence. The syndesmosis stayed intact in 50% although the fibula fractured at the level of the tibial plafond. Stage IV lesions were registered in 25%. The overall low bone mineral density showed a positive correlation to the angle at which the fibula fracture occurred. CONCLUSIONS: We reproduced supination external rotation lesions according to Lauge-Hansen in osteoporotic ankles. There is a certain discrepancy between the obligatory lesion of the inferior anterior tibiofibular syndesmosis at stage II according to Lauge-Hansen, as we observed an intact syndesmosis in 50% at stage II. Stage IV defining medial malleolar fractures were reproduced after Lauge-Hansen and Michelson et al.