Bone marrow edema (BME) is one of the most common findings on magnetic resonance imaging (MRI) after an ankle injury but can be present even without a history of trauma. This article will provide a systematic overview of the most common disorders in the ankle and foot associated with BME. The presence of BME is an unspecific but sensitive sign of primary pathology and may act as a guide to correct and systematic interpretation of the MR examination. The distribution of BME allows for a determination of the trauma mechanism and a correct assessment of soft tissue injury. The BME pattern following an inversion injury involves the lateral malleolus, the medial part of the talar body, and the medial part of the distal tibia. In other cases, a consideration of the distribution of BME may indicate the mechanism of injury or impingement. Bone in direct contact with a tendon may lead to alterations in the bone marrow signal where BME may indicate tendinopathy or dynamic tendon dysfunction. Changed mechanical forces between bones in coalition may lead to BME. Degenerative changes or minor cartilage damage may lead to subchondral BME. Early avascular necrosis, inflammation, or stress fracture may lead to more diffuse BME; therefore, a detailed medical history is crucial for correct diagnosis. A systematic analysis of BME on MRI can help to determine the trauma mechanism and thus assess soft tissue injuries and help to differentiate between different etiologies of nontraumatic BME.

Purpose This study aimed to test the hypothesis that routine MRI ankle can be used to evaluate dimensions and correlations between dimensions of single and double fascicular variants of the ATFL and the CFL. Methods We reviewed ankle MRIs for 251 patients. Differences between the length, thickness, width, and length of the bony attachments were evaluated twice. P < .05 was considered as significant. Results For the ATFL, we observed a negative correlation between thickness and width, with a positive correlation between thickness and length (p < 0.001). The average values for the ATFL were thickness, 2.2 ± 0.05 mm; length, 21.5 ± 0.5 mm; and width, 7.6 ± 0.6 mm. The average values for the CFL were thickness, 2.1 ± 0.04 mm; length, 27.5 ± 0.5 mm; and width, 5.6 ± 0.3 mm. A negative correlation was found between length and width for the CFL (p < 0.001). Conclusions Routine MRI showed that most dimensions of the ATFL and CFL correlate with each other, which should be considered when planning new reconstruction techniques and developing a virtual biomechanical model of the human foot. Level of evidence III

Aim: This imaging anatomy study aimed at detecting anatomical variations and potential interconnections of the superior peroneal retinaculum to other lateral stabilizing structures. Materials and methods: We retrospectively reviewed the imaging archives of 63 patients (38 females, 25 males, mean age 32.7, range 18–58 years) with available ankle US, MR and CT images to detect whether US and MR can detect the presence of interconnections between the superior peroneal retinaculum and the anterior talofibular ligament, inferior extensor retinaculum and peroneal tendon sheath. We evaluated the presence of common anatomical variations including low peroneus brevis muscle belly, peroneal tubercle, os peroneum, and retromalleolar fibular groove shape in relation to the presence of superior peroneal retinaculum connections. Results: The connections of the superior peroneal retinaculum can be revealed on magnetic resonance imaging (MRI) and ultrasound (US). The connection to the anterior talofibular ligament was located (a) inferior to the lateral malleolus, (b) at the level of the lateral malleolus and (c) on both levels, respectively (a) 49.2% on MRI and 39.7% on US, p <0.05, (b) 44.4% and 58.7%, p <0.05, 36.5% and (c) 27%, p <0.05. Superior peroneal retinaculum–inferior extensor retinaculum (MRI 47.6%, US 28.6% p <0.001) and superior peroneal retinaculum–peroneal tendon sheath (MRI 22.2%, US 25.4% p >0.05) connections were also found both on MR and US. Conclusion: Ankle US and MR revealed interconnections between the superior peroneal retinaculum and the anterior talofibular ligament, inferior extensor retinaculum, and superior peroneal retinaculum. Our results are a starting point for further studies on the connections of the superior peroneal retinaculum and the applicability of ultrasound and MRI in assessing their occurrence. Knowledge of the anatomical connections of the superior peroneal retinaculum may help radiologists with the assessment of lateral ankle injuries, and surgeons with treatment planning.