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.

Characteristics and classification of medial malleolar fractures.

AIMS: The morphology of medial malleolar fracture is highly variable and difficult to characterize without 3D reconstruction. There is also no universally accepeted classification system. Thus, we aimed to characterize fracture patterns of the medial malleolus and propose a classification scheme based on 3D CT reconstruction. METHODS: We retrospectively reviewed 537 consecutive cases of ankle fractures involving the medial malleolus treated in our institution. 3D fracture maps were produced by superimposing all the fracture lines onto a standard template. We sliced fracture fragments and the standard template based on selected sagittal and coronal planes to create 2D fracture maps, where angles α and ß were measured. Angles α and ß were defined as the acute angles formed by the fracture line and the horizontal line on the selected planes. RESULTS: A total of 121 ankle fractures were included. We revealed several important fracture features, such as a high correlation between posterior collicular fractures and posteromedial fragments. Moreover, we generalized the fracture geometry into three recurrent patterns on the coronal view of 3D maps (transverse, vertical, and irregular) and five recurrent patterns on the lateral view (transverse, oblique, vertical, Y-shaped, and irregular). According to the fracture geometry on the coronal and lateral view of 3D maps, we subsequently categorized medial malleolar fractures into six types based on the recurrent patterns: anterior collicular fracture (27 type I, 22.3%), posterior collicular fracture (12 type II, 9.9%), concurrent fracture of anterior and posterior colliculus (16 type III, 13.2%), and supra-intercollicular groove fracture (66 type IV, 54.5%). Therewere three variants of type IV fractures: transverse (type IVa), vertical (type IVb), and comminuted fracture (type IVc). The angles α and ß varied accordingly. CONCLUSION: Our findings yield insight into the characteristics and recurrent patterns of medial malleolar fractures. The proposed classification system is helpful in understanding injury mechanisms and guiding diagnosis, as well as surgical strategies. Cite this article: Bone Joint J 2021;103-B(5):931-938.

Evaluation of the Reproducibility of Lauge-Hansen, Danis-Weber, and AO Classifications for Ankle Fractures / Avaliação da reprodutibilidade das classificações Lauge-Hansen, Danis-Weber e AO para fraturas do tornozelo

Abstract Objective The present study aims to analyze the intra- and interobserver reproducibility of the Lauge-Hansen, Danis-Weber, and Arbeitsgemeinschaft für Osteosynthesefragen (AO) classifications for ankle fractures, and the influence of evaluators training stage in these assessments. Methods Anteroposterior (AP), lateral and true AP radiographs from 30 patients with ankle fractures were selected. All images were evaluated by 11 evaluators at different stages of professional training (5 residents and 6 orthopedic surgeons), at 2 different times. Intra- and interobserver agreement was analyzed using the weighted Kappa coefficient. Student t-tests for paired samples were applied to detect significant differences in the degree of interobserver agreement between instruments. Results Intraobserver analysis alone had a significant agreement in all classifications. Moderate to excellent interobserver agreement was highly significant (p ≤ 0.0001) for the Danis-Weber classification. The Danis-Weber classification showed, on average, a significantly higher degree of agreement than the remaining classification systems (p ≤ 0.0001). Conclusion The Danis-Weber classification presented the highest reproducibility among instruments and the evaluator's little experience had no negative influence on the reproducibility of ankle fracture classifications. Level of Evidence II, Diagnostic Studies - Investigating a Diagnostic Test.

Resumo Objetivo Avaliar a reprodutibilidade intra- e interobservador das classificações de Lauge-Hansen, Danis-Weber e Arbeitsgemeinschaft für Osteosynthesefragen (AO) para as fraturas de tornozelo, e a influência do estágio de formação dos participantes na avaliação. Métodos Foram selecionadas radiografias de 30 pacientes com fratura de tornozelo nas incidências anteroposterior (AP), perfil e AP verdadeiro. Todas as imagens foram avaliadas por 11 participantes em diferentes estágios de formação profissional (cinco residentes e seis cirurgiões ortopédicos), em dois momentos distintos. Analisou-se a concordância inter- e intraobservador por meio do coeficiente Kappa ponderado. O teste t de Student para amostras pareadas foi aplicado para verificar se havia diferença significativa no grau de concordância interobservador entre os instrumentos. Resultado Observou-se que existe concordância significativa em todas as classificações quando da análise intraobservador isolada. Existe concordância interobservador altamente significativa de grau moderado a ótimo na classificação de Danis-Weber (p ≤ 0,0001). A classificação de Danis-Weber apresentou, em média, grau de concordância significativamente maior que as outras classificações (p ≤ 0,0001). Conclusão A classificação de Danis-Weber se mostrou a mais reprodutiva entre os instrumentos avaliados, e a pouca experiência do avaliador não influencia negativamente a reprodutibilidade das classificações das fraturas do tornozelo. Nível de Evidência II, Estudos Diagnósticos - Investigação de um Exame para Diagnóstico.

Ankle fracture classification using deep learning: automating detailed AO Foundation/Orthopedic Trauma Association (AO/OTA) 2018 malleolar fracture identification reaches a high degree of correct classification.

Background and purpose - Classification of ankle fractures is crucial for guiding treatment but advanced classifications such as the AO Foundation/Orthopedic Trauma Association (AO/OTA) are often too complex for human observers to learn and use. We have therefore investigated whether an automated algorithm that uses deep learning can learn to classify radiographs according to the new AO/OTA 2018 standards.Method - We trained a neural network based on the ResNet architecture on 4,941 radiographic ankle examinations. All images were classified according to the AO/OTA 2018 classification. A senior orthopedic surgeon (MG) then re-evaluated all images with fractures. We evaluated the network against a test set of 400 patients reviewed by 2 expert observers (MG, AS) independently.Results - In the training dataset, about half of the examinations contained fractures. The majority of the fractures were malleolar, of which the type B injuries represented almost 60% of the cases. Average area under the area under the receiver operating characteristic curve (AUC) was 0.90 (95% CI 0.82-0.94) for correctly classifying AO/OTA class where the most common major fractures, the malleolar type B fractures, reached an AUC of 0.93 (CI 0.90-0.95). The poorest performing type was malleolar A fractures, which included avulsions of the fibular tip.Interpretation - We found that a neural network could attain the required performance to aid with a detailed ankle fracture classification. This approach could be scaled up to other body parts. As the type of fracture is an important part of orthopedic decision-making, this is an important step toward computer-assisted decision-making.

Injury mechanism affects the stability of suture-button syndesmosis fixation.

BACKGROUND: Ankle syndesmosis injury is a common condition, and the injury mechanism can be sorted into pure syndesmosis injury, Weber-B, and Weber-C type fractures. This study aims to evaluate the treatment outcomes and stability of suture-button fixation for syndesmosis injury with different injury mechanisms. We hypothesized that injury mechanisms would alter the stability of suture-button fixation. METHODS: We retrospectively reviewed 63 patients with ankle syndesmosis injury who underwent surgery with TightRope (Arthrex, Naples, FL, USA) from April 2014 to February 2019. The stability of suture-button fixation with TightRope was evaluated by comparing the preoperative, postoperative, and final follow-up measurements of tibiofibular clear space (TFCS), tibiofibular overlap (TFO), and medial clear space (MCS). A subgroup analysis for each demographic group and injury type including pure syndesmosis injury, Weber-B, and Weber-C type fractures were performed. RESULTS: Syndesmosis was effectively reduced using TightRope. After the index surgery, the tibiofibular clear space was reduced from 7.73 to 4.04 mm, the tibiofibular overlap was increased from 3.05 to 6.44 mm, and the medial clear space was reduced from 8.12 to 3.54 mm. However, syndesmosis widening was noted at the final follow-up, especially in Weber-C type fractures (TFCS 3.82 to 4.45 mm, p < 0.01 and TFO 6.86 to 6.29 mm, p = 0.04). Though widened, the final follow-up values of tibiofibular clear space and tibiofibular overlap were in the acceptable range. Postoperatively and at the final follow-up, medial clear space was found to be significantly larger in the Weber-C group than in the pure syndesmosis and Weber-B groups (p < 0.05). CONCLUSIONS: Suture-button fixation can offer anatomic reduction and dynamic fixation in syndesmosis injuries. However, when using this modality for Weber-C type fractures, more attention should be focused on the accuracy of reduction, especially of medial clear space, and rediastasis should be carefully monitored. TRIAL REGISTRATION: This trial was retrospectively approved by TMU-JIRB. Registration number N202004122, and the date of approval was May 06, 2020. LEVEL OF EVIDENCE: III.

Comparison of radiographs and CT features between posterior Pilon fracture and posterior malleolus fracture: a retrospective cohort study.

OBJECTIVES: This study explored the morphological differences between posterior Pilon fracture and posterior malleolus fracture from radiographs and CT to provide detail for diagnosis and treatment of them. METHODS: Radiographs and CT imaging data of 174 patients with distal posterior tibial fractures who were treated from January 2013 to January 2019 were retrospectively analyzed. Based on the operation and imaging examination, the fractures were classified into posterior Pilon fractures and posterior malleolus fractures. Radiographic parameters including the width, height, depth, α angle, ß angle, γ angle, fragment area ratio 1 (FAR1), δ angle and fragment area ratio 2 (FAR2) of ankle mortise were measured. RESULTS: There were 96 posterior Pilon fractures (Type I: 30, Type II: 22 and Type III: 44) and 78 posterior malleolus fractures (Type I: 40 and Type II: 38). The ankle depth, α angle, γ angle, FAR1 and FAR2 of posterior Pilon fractures were larger than these of posterior malleolus fractures (p < 0.05). In addition, FAR1 and FAR2 of Type II and Type III posterior Pilon fractures were significantly larger than these of Type I (p < 0.05). FAR1 and FAR2 of Type I posterior malleolus fractures were significantly smaller than these of Type II (p < 0.05). CONCLUSION: Radiographs combined with CT analysis is an effective method to accurately distinguish morphological features between posterior Pilon fracture and posterior malleolus fracture. ADVANCES IN KNOWLEDGE: Radiographs combined with CT distinguished the fracture of posterior malleolus and posterior Pilon rapidly and accurately, instead of operation.

Orthopedic treatment and early weight-bearing for bimalleolar ankle fractures in elderly patients: Quality of life and complications.

INTRODUCTION: Non-operative treatment of Weber's type B ankle fractures is essential in elderly patients. However, there is controversy in the post-reduction management of the fracture between the use of early weight-bearing or traditional treatment and non-weight-bearing for 6-8 weeks. There is limited evidence available regarding which rehabilitation regimen should be included. This study aimed to compare the quality of life and the number of complications between the two types of intervention (weight-bearing and non-weight-bearing). METHODS: Prospective cohort study. The quality of life was analyzed through the SF-12 and the Barthel Index at 6 weeks, one year and two years. The mean age was 83 ± 3 years in the weight-bearing group and 82 ± 3 in the non-weight-bearing group. In addition, the associated complications and costs were analyzed. RESULTS: A total of 70 patients were assigned in two groups: a control group of 37 patients (nonweight-bearing) and an experimental group of 33 patients (weight-bearing). A significant difference was observed in favor of early weight-bearing in SF-12 both, in the short and long terms (52.9 ± 5.3 vs 64.9 ± 4.6; p < 0.001 and 69.8 ± 4.1 vs 81.0 ± 3.6; p < 0.001). Significant differences were also observed in favor of early loading with respect to the Barthel Index (54.3 ± 4.9 vs 64.2 ± 3.9; p < 0.001 and 70.6 ± 4.2 vs 80.4 ± 3.0; p < 0.001). There were no significant differences in the complication rate between the two groups. CONCLUSION: Early weight-bearing improves the quality of life and functionality in elderly patients with Weber type B fracture without increasing complications.

The effect of computerised tomography on operative planning in posterior malleolus ankle fractures.

BACKGROUND: The aim of this project was to analyse whether a CT influences surgical planning in ankle fracture involving the posterior malleolus. METHODS: Twenty consecutive patients with fractures involving the posterior malleolus were retrospectively selected and had their plain radiographs and CT scan anonymised. Initially, radiographs alone were presented to nine trauma surgeons to formulate a surgical plan individually. After a minimum of 6 weeks, the same process was repeated with CT scans available. RESULTS: The surgical approach for ankle fracture fixation changed in 32.7% of cases following CT scan review. A CT scan altered the decision to stabilise the posterior malleolus in 25.6% and the decision of whether to stabilise the syndesmosis in 16.6% of cases. CONCLUSIONS: This study demonstrates that a pre-operative CT scan changes the surgical approach in 32.7% of cases and therefore we recommend use of CT scanning in this subset of ankle injuries.

A New Classification System for Pilon Fractures Based on CT Scan: An Independent Interobserver and Intraobserver Agreement Evaluation.

BACKGROUND DATA: A new pilon fracture classification system based on CT scan data was recently published, showing almost perfect interobserver and intraobserver agreement among the authors who developed it. However, an independent assessment has not been done. OBJECTIVE: To do an independent agreement evaluation of the new pilon fracture classification system with physicians with different levels of expertise in the management of pilon fractures. METHODS: Seventy-one cases of acute pilon fracture were retrospectively collected. Fractures were classified by six evaluators (three foot and ankle surgeons and three orthopaedic surgery residents) using CT scans according to the morphological grading of the new pilon fracture classification system developed by Leonetti et al. Cases were presented to the same evaluators in a random sequence after a 6-week interval to determine intraobserver agreement. The kappa coefficient (κ) was used to determine agreement among evaluators. RESULTS: The interobserver agreement was substantial regarding the main fracture type (I, II, III, or IV), with an overall κ value of 0.69 (0.65 to 0.72). When including the II and III subtypes, the overall agreement was still substantial, with a κ value of 0.61 (95% confidence interval: 0.58 to 0.64). The intraobserver agreement was substantial when considering the main fracture categories (I, II, III, or IV), with a κ value of 0.78 (confidence interval: 0.72 to 0.84), and full agreement at the type level was observed in 76% (324/426) of evaluations. There was no notable difference between the foot and ankle surgeons and orthopaedic surgery residents in the interobserver and intraobserver agreement. CONCLUSION: The new classification system demonstrated substantial interobserver and intraobserver agreement between evaluators with different levels of expertise in the management of pilon fractures. Prospective studies should be done to evaluate its prognostic value and utility in clinical practice.

Impact of two- and three-dimensional computed tomography use on intraobserver and interobserver reliabilities of pilon fracture classification and treatment recommendation.

BACKGROUND: Two-dimensional (2D) and three-dimensional (3D) computed tomography (CT) have been increasingly used in various intra-articular fractures including pilon fracture. However, no study has investigated intraobserver and interobserver reliabilities of pilon fracture classification using 3D CT images. HYPOTHESIS: (1) Intraobserver and interobserver agreements of fracture classifications and treatment recommendations will improve by using 2D CT images compared to using plain radiographs only; (2) agreements will improve by adding 3D CT images compared to adding 2D CT images; and (3) agreements of orthopedic residents rather than specialists will be influenced more by imaging modality. MATERIALS AND METHODS: Ten orthopedic specialists and 10 residents completed a survey to classify the fractures according to the Rüedi-Allgöwer and AO/OTA classifications and to select treatment options using 25 pilon fracture images. The survey was conducted using plain radiographs, with 2D and 3D CT images introduced 3 and 6weeks later, respectively. Kappa coefficients were calculated to determine reliabilities. RESULTS: Intraobserver reliabilities for fracture classifications in specialists significantly improved by using 2D images compared to using plain radiographs only. Addition of 3D CT did not significantly improve intraobserver reliabilities compared to those with 2D CT. Use of 2D CT images significantly improved overall interobserver agreement of both classifications, with the improvement being greater for residents. Use of 3D CT images did not improve the interobserver reliability of both classifications. Overall interobserver reliabilities for treatment recommendations did not significantly differ according to the imaging modality. However, interobserver agreement among residents significantly improved from slight agreement using radiographs only to fair agreement using 2D CT images. DISCUSSION: Intraobserver and interobserver reliabilities of pilon fracture classification and treatment recommendations did not improve between using 3D and 2D CT. Using 2D CT images improved the intraobserver and interobserver reliabilities of the fracture classifications in specialists and the interobserver reliabilities of the fracture classifications and the treatment recommendations in residents. LEVEL OF EVIDENCE: IV, case control study.

Ankle Fracture Stability-Based Classification: A Study of Reproducibility and Clinical Prognostic Ability.

OBJECTIVE: To compare the reproducibility and prognostic capacity of 2 commonly used ankle fracture classifications to the stability-based classification. METHODS: One hundred ninety-three consecutive rotational-type ankle fractures treated during a year at our institution in patients older than 18 years were retrospectively analyzed. Pilon and pathologic fractures were excluded. The fractures were treated by attending physicians who were unaware of the stability-based classification system. Three observers classified injury radiographs using the Lauge-Hansen, Weber/AO, and stability-based classifications systems. Reproducibility (interobserver variation) of each classification system was calculated using kappa statistics. Prognostic values were evaluated by calculating the area under the curve for the receiver-operating characteristic curves (using surgery as the positive outcome). RESULTS: The stability-based and Weber/AO classifications showed better reproducibility [kappa 0.938 (95% confidence interval 0.921-0.952), kappa 0.97 (0.961-0.976)], respectively, than the Lauge-Hansen [kappa 0.74 (0.664-0.795); P < 0.05]. The stability-based classification was more accurate (P < 0.001) in predicting surgical treatment [area under the curve 0.883 (95% confidence interval 0.852-0.914)] compared with the other 2 classifications [0.626 (0.576-0.675) and 0.698 (0.641-0.755)], respectively. CONCLUSIONS: The stability-based classification was both highly reproducible (kappa 0.938) and had superior prognostic capacity to identify patients who needed surgical intervention compared with both the Lauge-Hansen and AO/Weber classification systems. Importantly, there were no patients who were classified as stable who failed nonoperative treatment. This extends earlier studies by directly demonstrating its prognostic advantage to other classification systems.

Clinical Outcomes of Hyperplantarflexion Variant Compared With Supination External Rotation Ankle Fractures: A Matched-Cohort Analysis.

Recent literature has reported an uncategorized hyperplantarflexion variant ankle fracture characterized by a posteromedial fragment separate from the posterior or medial malleolar fragments. The current study sought to determine whether the outcomes for surgically treated hyperplantarflexion variant fractures are similar to the more common supination external rotation (SER) IV fractures. A prospective registry of operatively treated ankle fractures was queried to create 2 age- and gender-matched cohorts: hyperplantarflexion variant and SER IV fractures. Each cohort had 23 patients (18 females), and matched pairs were within 2 years of age at the date of surgery. Patient demographics, comorbidities, and Foot and Ankle Outcomes Scores at minimum 12 months after the index surgery were compared. The cohorts were similar with respect to body mass index, the length of the clinical follow-up, medical comorbidities, dislocation rate, and postoperative articular incongruity (p > .05). Patient-reported outcomes demonstrated no statistically or clinically significant differences within any domain and were as follows: symptoms (70.8 versus 77.8, p = .11), pain (80.7 versus 85.0, p = .33), activities of daily living (83.7 versus 89.2, p = .23), sports (67.4 versus 73.4, p = .33), and quality of life (57.3 versus 63.9, p = .24) for the hyperplantarflexion and SER IV groups, respectively. No significant differences were found in the rang`e of motion for dorsiflexion (17.7° versus 18.1°, p = .52) or for plantarflexion (48.6° versus 47.1°, p = .71). Patients treated surgically for hyperplantarflexion variant ankle fractures have similar 1-year clinical outcomes when compared with the more common SER IV fracture patterns, provided that the injury is correctly identified preoperatively and treated appropriately.

Ankle Fracture Classification: An Innovative System for Describing Ankle Fractures.

A good classification system is important for clinical handoffs, research, and clinical treatment guidelines. A reliable classification system shows good interobserver and intraobserver agreement. This study analyzed the interobserver and intraobserver agreement of a descriptive system for ankle fractures and the Lauge-Hansen classification. Three groups of observers (experts, semiexperts, and novices) scored a total of 20 ankle radiographs. All ankle radiographs were classified according to the Lauge-Hansen and Danis-Weber classifications. The ankle fractures were subsequently reviewed in a descriptive manner for the following features: number of affected malleoli, type of fracture of the lateral and medial malleolus, and congruence of the ankle joint. After 2 weeks, the same set of radiographs were reviewed. For interobserver and intraobserver variability, the separate groups were used for analysis, and the Fleiss (multirater) κ values were calculated. The interobserver agreement for the Lauge-Hansen classification was moderate for the experts, fair for semiexperts, and slight for novices (κ = 0.45, κ = 0.37, and κ = 0.16). All factors of the descriptive system had better interobserver agreement than the Lauge-Hansen classification, except for the agreement on the type of fracture of the lateral malleolus. The intraobserver agreement of the Lauge-Hansen classification was substantial for the experts, moderate for the semiexperts, and fair for the novice observers (κ = 0.70, κ = 0.49, and κ = 0.26). The intraobserver agreement was better for all factors of the descriptive system compared with the Lauge-Hansen classification. The descriptive system presented in this study shows less variability between observers than the Lauge-Hansen classification. This system has clinical implications and is easy to use for clinicians with mixed levels of experience. It has the potential to improve clinical and research handoffs and overcome the limitations of current classification systems.

Reproducibility of the stability-based classification for ankle fractures.

BACKGROUND: Classification of ankle fracture is important when deciding for operative or conservative treatment. This study rates the reproducibility of ankle stability assessment and compares it with the classification by Lauge-Hansen and Arbeitsgemeinschaft für Osteosyntesefragen (AO) in adult patients with primary ankle fractures. METHODS: A total of 496 consecutive ankle fractures were included, and the X-ray images were reviewed 2 times by 2 medical students, 2 residents, and 1 consultant in orthopedic traumatology. The raters were blinded to each other and to their own results. Unweighted Kappa statistics were used to assess reproducibility. RESULTS: Overall mean (95% CI) interrater Kappa results were 0.65 (0.64; 0.68) for Lauge-Hansen, 0.62 (0.60; 0.63) for AO and 0.61 (0.57; 0.62) for the stability assessment. The intrarater results ranged from a mean Kappa of 0.64-0.80 for the medical students, 0.65-0.81 for the residents and 0.82-0.84 for the consultant. CONCLUSION: The stability assessment has substantial to almost-perfect agreement which is comparable to the Lauge-Hansen and AO classifications.

Characteristics and proposed classification system of posterior pilon fractures.

Posterior pilon fractures involve the medial malleolus (MM). Our purpose was to define the characteristics of posterior pilon fractures, and propose a classification system based on fracture morphology and type of management.The records of patients with posterior pilon fractures treated from 2011 to 2015 were retrospectively reviewed. The injury mechanism, fracture morphology, surgical approach, and follow-up results were reviewed and analyzed. This study was approved by the Institutional Review Board of PLA Army General Hospital.Thirty-six patients, 18 males and 18 females (mean age: 48.9 years) were included in the study. Four characteristics were used to define posterior pilon fractures. A simple posterolateral approach or a combined posterolateral and posteromedial approach was used for reduction and fixation in all patients. The mean follow-up time was 28.2 months, and at the end of follow-up, the mean American Orthopedic Foot and Ankle Society Score (AOFAS) was 82.5 points (range: 35-100 points). Based on injury mechanism and fracture morphology, we classified posterior pilon fractures into 3 types that suggest the optimal surgical approach: type I, a single complete fracture fragment; type II, a posterior malleolus fracture with 2 subtypes; type III, a posterior malleolus fracture associated with complete MM fracture with 2 subtypes.The proposed classification system based on injury mechanism and fracture morphology can guide the surgical approach to maximize outcomes.

Management of Isolated Lateral Malleolus Fractures.

Isolated lateral malleolus fractures represent one of the most common injuries encountered by orthopaedic surgeons. Nevertheless, appropriate diagnosis and management of these injuries are not clearly understood. Ankle stability is maintained by ligamentous and bony anatomy. The deep deltoid ligament is considered the primary stabilizer of the ankle. In the setting of an isolated lateral malleolus fracture, identifying injury to this ligament and associated ankle instability influences management. The most effective methods for assessing tibiotalar instability include stress and weight-bearing radiographs. Clinical examination findings are important but less reliable. Advanced imaging may not be accurate for guiding management. If the ankle is stable, nonsurgical management produces excellent outcomes. In the case that clinical/radiographic findings are indicative of ankle instability, surgical fixation options include lateral or posterolateral plating or intramedullary fixation. Locking plates and small or minifragment fixation are important adjuncts for the surgeon to consider based on individual patient needs.

Epidemiology of Adult Ankle Fractures: 1756 cases identified in Norrbotten County during 2009-2013 and classified according to AO/OTA.

BACKGROUND: The ankle fracture is one of the most common fractures, increasing in an ageing population, but not generally seen as an osteoporotic fracture. The aim of this study was to examine the relationship between different AO/OTA classes of ankle fractures, age, sex and type of trauma. METHODS: Ankle fractures, treated at any of the hospitals in Norrbotten County in Sweden between 2009 and 2013, were retrospectively identified and classified according to the AO/OTA-classification system. Information about the trauma mechanism was also obtained. RESULTS: In Norrbotten County, 1756 ankle fractures in 1735 patients aged 20 years or older were identified. This gave an incidence in the county of 179 per 100,000 person-years. Of these patients, 34.6% were 65 years or older, 58.4% were women and 68.2% of the trauma leading to a fracture was defined as low-energy. In 1.5% of the cases the fractures were open. Incidences of type B fractures increased substantially with age, from 62 (95% CI 50-77) at 30-39 years of age to 158 (95% CI 131-190) in patients older than 80 years of age per 100,000 person-years. Type B fractures showed a slightly higher proportion of low-energy trauma while type C showed a lower mean age and proportion of women. CONCLUSIONS: This study shows an incidence of 179 adult ankle fractures annually per 100,000 persons. More than two thirds of the fractures were caused by a low-energy trauma and ankle fractures are more frequent among females. Females generally have an increased incidence during their life, mainly between the ages of 30 and 60. This is in contrast to men who have more of an even distribution throughout their life. Classification according to AO/OTA reveals some heterogeneity among the classes of ankle fractures in age and gender as well as the energy involved in the trauma.

X-ray features to predict ankle fracture mechanism.

INTRODUCTION: The genetic Lauge-Hansen classification has been traditionally used for reconstruction of the mechanism of ankle injury. The ability of the Lauge-Hansen classification to predict actual mechanism of the injury has been questioned in recent studies, leaving a void in medicolegal reasoning. The aim of this study is to identify morphologic features of malleolar fractures on plain X-rays that may be used to reveal the fracture mechanism. MATERIAL AND METHODS: Radiographs of 78 patients with acute malleolar fractures were analyzed and compared with fracture mechanisms reported by these patients. RESULTS: A modified Pankovich classification of medial malleolus fractures and the presence of a posterior malleolus fracture were able to significantly predict the mechanism of fracture reported by the patient (p<0.05). Lateral fracture morphology was not useful for predicting the fracture mechanism except for infrasyndesmotic fractures pointing to a supination mechanism. CONCLUSION: A supination mechanism of the fracture can be predicted by observing pure ligamentous or chip-avulsion deltoid injury. The presence of an anterior colliculus fracture of the medial malleolus is correlated with a pronation mechanism. A fracture of the posterior malleolus correlates with pronation while an intact posterior malleolus correlateds with supination as a fracture mechanism. Absolute determination of fracture mechanism from the X-ray morphology of the fracture is impossible in the majority of cases.