Ultrasonography for the diagnosis of deltoid injury in supination external rotation ankle fractures - A scoping review.

BACKGROUND: Lauge-Hansen supination external rotation (SER)-type ankle fractures are very common and account for up to 75% of all ankle fractures. Assessing deltoid integrity is key for surgical decision making. Ultrasound has been used recently to assess the integrity of the deltoid ligament and differentiate between SER II and SER IV fractures. The aim of this article is to review the literature for studies assessing the diagnostic accuracy of ultrasound in this group of patients. METHODS: After registering the protocol with PROSPERO, Embase, Ovid MEDLINE, Web of Science Core Collection, and Google Scholar were systematically searched. Studies that satisfied the following inclusion criteria were assessed: (1) Adult patients (>16 years), (2) Acute SER-type ankle fractures assessed within 2 weeks of the injury, (3) Diagnostic accuracy studies. Risk of bias assessment was conducted and a narrative synthesis of the results presented. RESULTS: A total of five studies satisfied our inclusion criteria and were included for review. These had a total of 175 patients studied. All studies showed a sensitivity of 100% and specificity of 90-100% for detecting a complete tear of the deltoid. All papers had a significant risk of bias inherent to the design. Only patients undergoing surgery were exposed to the gold standard of operative intervention. CONCLUSION: Ultrasound scan has shown excellent diagnostic accuracy for detecting complete deltoid ruptures in SER ankle fractures. These results however should be interpreted with caution. Perhaps a different approach is needed to assess the efficacy of ultrasound scans in patient with SER type fractures.

Ankle Joint Pressure in Supination-External Rotation Injuries: A Biomechanical Study in an Unrestrained Cadaver Model.

BACKGROUND: Previous biomechanical studies simulating supination-external rotation (SER) IV injuries revealed different alterations in contact area and peak pressure. We investigated joint reaction forces and radiographic parameters in an unrestrained, more physiological setup. METHODS: Twelve lower leg specimens were destabilized stepwise by osteotomy of the fibula (SER II) and transection of the superficial (SER IVa) and the deep deltoid ligament (SER IVb) according to the Lauge-Hansen classification. Sensors in the ankle joint recorded tibio-talar pressure changes with axial loading at 700 N in neutral position, 10° of dorsiflexion, and 20° of plantarflexion. Radiographs were taken for each step. RESULTS: Three of 12 specimen collapsed during SER IVb. In the neutral position, the peak pressure and contact area changed insignificantly from 2.6 ± 0.5 mPa (baseline) to 3.0 ± 1.4 mPa (SER IVb) (P = .35) and from 810 ± 42 mm2 to 735 ± 27 mm2 (P = .08), respectively. The corresponding medial clear space (MCS) increased significantly from 2.5 ± 0.4 mm (baseline) to 3.9 ± 1.1 mm (SER IVb) (P = .028).The position of the ankle joint had a decisive effect on contact area (P = .00), center of force (P = .00) and MCS (P = .01). CONCLUSION: Simulated SER IVb injuries demonstrated radiological, but no biomechanical changes. This should be considered for surgical decision making based on MCS width on weightbearing radiographs. LEVELS OF EVIDENCE: Not applicable. Biomechanical study.

Compatibility of Lauge-Hansen Classification Between Plain Radiographs and Magnetic Resonance Imaging in Ankle Fractures.

We evaluated the accuracy of the predictive injury sequences of the Lauge-Hansen (L-H) classification using magnetic resonance imaging (MRI) in patients with ankle fractures and determined the possible causes of mismatch. Sixty-five patients with ankle fractures who had a complete series of anteroposterior, lateral, and oblique radiographs and ankle MRI studies available were included. The fracture pattern was assigned by 2 senior orthopedic surgeons according to the L-H classification system. The syndesmotic ligaments, lateral collateral ligaments, and medial deltoid complex ligaments were evaluated on the preoperative MRI scans. Comparisons were performed between the predicted ankle ligamentous injury based on the radiographic L-H classification and preoperative MRI analysis. Of the 65 feet in 65 patients, 50 feet (76.9%) were classified as having a supination-external rotation (SER) fracture, 6 feet (9.2%) as having a pronation-external rotation fracture, 4 feet (6.2%) as having a supination adduction fracture, and 2 feet (3.1%) as having a pronation abduction fracture. The overall compatibility of the radiologic classification with the MRI classification was 66.1%. In the evaluation of 50 feet with the MRI SER designation, maximum compatibility was found for stage 4 (77.3%). The main cause for the discrepancy in the SER designation was missing the presence of deltoid ligament disruption on the plain radiographs, especially in the stage 2 and 3 SER fracture pattern. In the evaluation of deltoid complex injuries, all injuries were localized to the anterior part of the medial deltoid complex. The validity of the L-H classification system was low. A new classification system is needed to address the medial malleolus fracture or deltoid complex injuries without posterior injury. Also, stress radiographs could be added to standard radiographs for the classification to address deltoid complex injuries.

Predicting syndesmotic injuries in ankle fractures: a new system based on the medial malleolar focus.

The early establishment of the diagnosis of a syndesmotic injury is essential for treatment selection. However, such injuries may not be apparent radiographically. Previous studies have attempted to describe correlations between medial malleolar fracture geometry and syndesmotic disruption. The main objective of this study was to create predictive models for assessing syndesmotic injuries based on an originally described angle, i.e., the medial crural-focal angle (MCFA). This study included 138 ankle fractures involving the medial malleolus. Any measure from the plain radiograph that could potentially lead to the suspicion of a syndesmotic disruption was recorded, and the newly described MCFA (formed by the main line of the medial malleolus fracture and a line perpendicular to the bearing surface of the tibial plafond) was also recorded. The inter- and intraobserver reliabilities were obtained using Krippendorff's alpha coefficients. To examine the predictive abilities of every parameter, several statistical methods were applied including logistic regression, an ad hoc clinical rule, and discriminant analysis. After variable selection, we obtained the best possible logistic model. The variables that were found to be statistically significant were the MCFA, the tibiofibular clear space (TFCS) and the type of injury in the Lauge-Hansen (L-H) classification. This model was tested by cross validation, which revealed a mean percentage of correctly classified patients of 88%. A simpler and more intuitive alternative model was sought that was based solely on the influences of the MCFA and the TFCS. Our study revealed that an absence of syndesmotic disruptions when the MCFA was under 60°, and there were no uninjured patients with tibiofibular clear space values over 6mm. Cross-validation revealed that the mean percentage of patients who were correctly classified with this model was 86%. The application of discriminant analysis to this combination of variables resulted in a function was able to correctly classify a mean of 84% of patients. In conclusion, three models that can predict syndesmotic injury using parameters from preoperative plain radiographs were obtained and validated. The MCFA measurement was in these models and found to be a reliable technique.

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.

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.

Arthroscopic diagnosis of tibiofibular syndesmosis disruption.

PURPOSE: We have been able to diagnose tibiofibular syndesmosis injury by ankle arthroscopy, and in the present study we compare these results with the results from plain radiographs. TYPE OF STUDY: Case series. METHODS: Thirty-eight type-B (Weber system) distal fibular fractures in 38 patients were diagnosed to determine whether tibiofibular syndesmosis disruption was present. According to the Lauge-Hansen system, 16 patients had supination-external rotation fractures and 22 had pronation-abduction fractures. Standard non-weight-bearing anteroposterior radiographs and mortise radiographs were evaluated. Furthermore, ankle arthroscopy was performed on all patients. RESULTS: Tibiofibular syndesmosis disruptions were diagnosed in 16 of the 38 patients (42%) by anteroposterior radiography, 21 of 38 patients (55%) by mortise radiography, and 33 of 38 patients (87%) by ankle arthroscopy. All of the patients who were diagnosed with tibiofibular syndesmosis disruption by anteroposterior radiography and mortise radiography were also confirmed by ankle arthroscopy to have injured their tibiofibular syndesmosis. In 12 patients, ankle arthroscopy was the only method used to diagnose the tibiofibular syndesmosis disruption. CONCLUSIONS: Ankle arthroscopy excels in term of the diagnosis ratio for tibiofibular syndesmosis disruption compared with both anteroposterior and mortise radiography. Therefore, we conclude that ankle arthroscopy is necessary for the correct diagnosis of tibiofibular syndesmosis disruption.

Pronation injuries of the ankle in children. Retrospective study of radiographical classification and treatment.

In a retrospective study in children aged 0-18 years, 457 ankle fractures in children were classified traumatologically according to Gerner-Smidt or Lauge-Hansen. Anatomically, ankle fractures with open growth plates were classified according to the Salter-Harris classification. Pronation injuries constituted 18% of the ankle injuries and showed different fracture patterns. In total 83 pronation injuries were found. Of these, 52 showed open growth plates: 25 pronation-abduction, 23 pronation-eversion, and 4 pronation-dorsal flexion injuries. The pronation-abduction injuries were classified into two groups. In 15, a detachment of the deltoid ligament at the medial malleolus, visible on radiographs as a minimal fragment or transverse fracture of the medial malleolus, was found; seven showed in addition a fracture through the growth plate (Salter-Harris type I or II) or a metaphyseal fracture of the distal fibula. In 10, a physeal fracture through the distal tibia (Salter-Harris type I) was found. Of these, seven had in addition a metaphyseal fibular fracture. Pronation-eversion injuries showed in 21 cases a physeal-metaphyseal fracture (Salter-Harris type II) with an antero-lateral metaphyseal fragment (Stage I-II); 17 had in addition a metaphyseal fibular fracture (Stage III). A minimal posterolateral metaphyseal fragment of the distal tibia represents the fourth stage but could not adequately be separated from the third, so Stages III and IV were combined. Pronation-dorsal flexion showed a physeal-metaphyseal fracture in four cases with an anteriorly situated metaphyseal fragment (Stages I-II); one case also had a metaphyseal fracture of the distal fibula (Stage III). Pronation-eversion injuries showed frequently displacement and were more commonly treated by reduction than pronation-abduction and supination injuries including supination-eversion injuries of intra-articular type. However, complete reduction of pronation-eversion injuries with closed methods often proved difficult.