Operative treatment of isolated epiphyseal fracture of the distal fibula: 1 case report and literature review.

Pediatric ankle injuries are common; ankle epiphyseal fractures are also common in children. But isolated distal epiphyseal fibular fractures of the distal fibula are clinically rare. We describe one unusual case of an adolescent with a completely displaced Salter-Harris type II distal fibular epiphyseal fracture. The attempt of closed reduction failed, and the patient required open reduction and internal fixation. The localized periosteum and the superior peroneal retinaculum were avulsed from the distal fibular metaphysis, with the peroneal tendons underneath exposed but no obvious subluxation. To the best of our knowledge, this combination of injuries has not been previously reported.

Traumatic proximal tibiofibular fracture and dislocation.

BACKGROUND: Traumatic proximal tibiofibular fracture and dislocation (PTFD) have been rarely studied and are easily missed in clinical practice. PTFD is considered a marker of severely traumatized knees. The purpose of this study was to retrospectively analyze the incidence and impact of PTFD in traumatized knees with vascular injury. METHODS: Patients with knee trauma and vascular injury were included from January 2022 to October 2023. X-rays and CT scans of included patients were retrospectively analyzed to determine the presence of PTFD. Patients were further divided into PTFD group and non-PTFD group for further comparative analysis. RESULTS: A total of 27 patients (28 limbs) were included. Incidence of PTFD was 39.3% (11/28) in traumatic knee with vascular injury, including 8 anterolateral dislocations and 3 posteromedial dislocations. PTFD group had significantly more limbs with open injuries compared with non-PTFD group (10/11 VS 7/17, p<0.05). Amputation rate of PTFD group was as high as 40% (4/10), compared to 23.5% (4/17) in non-PTFD group. However, the difference between two groups was not statistically significant (p>0.05). CONCLUSIONS: PTFD was easily overlooked or missed. In traumatized knees with vascular injury, incidence of PTFD was high. The presence of PTFD might indicate severe knee trauma and the possibility of open injury. Although there was no significant difference compared with non-PTFD group, PTFD group had a relatively high amputation rate of 40%.

Joint preserving procedures for Takakura stage IIIB varus ankle osteoarthritis.

A man in his early 70s with right Takakura stage IIIB varus ankle osteoarthritis underwent medial opening wedge supramalleolar osteotomy with inframalleolar correction as joint preserving procedure. We also performed anteroinferior tibiofibular ligament (AITFL) resection with fibular shortening valgisation osteotomy to enhance the talar tilt correction. Postoperative decrease in talar tilt with dramatic symptom improvement was achieved. Performing the AITFL resection with fibular shortening valgisation osteotomy plus concomitant supramalleolar osteotomy and inframalleolar correction for Takakura stage IIIB varus ankle osteoarthritis resulted in successful improvement in talar tilt by making room for the valgus deviation of the talus.

[Design and application of a device for radiographic projection of the tibio-astragalangeal mortise]. / Diseño y aplicación de dispositivo para proyección radiográfica de la mortaja tibio-astragalina.

INTRODUCTION: ligamentous injuries of the distal tibiofibular syndesmosis resulting in its opening are common occurrences in traumatology; however, their diagnosis poses a challenge for orthopedic surgeons. The tibioastragaloid mortise radiograph view is the most commonly used method for diagnosing this type of injury, but its reliability is compromised due to variations in ankle positioning during the study, which often depend on the operator. OBJECTIVE: to demonstrate that the designed device achieves a correct and consistent radiographic image of the distal tibiofibular syndesmosis in the mortise view. MATERIAL AND METHODS: we present a prospective, longitudinal, observational study. We designed a polypropylene device that maintains the ankle at 90 degrees of dorsiflexion and 15 degrees of internal rotation. The device was used to take mortise view radiographs of healthy ankles, and corresponding measurements were taken to assess the syndesmosis. RESULTS: we evaluated a total of 46 radiographs of healthy ankles, with a predominance of left ankles. The obtained measurements were as follows: anterior tibiofibular distance (ATFD) ranged from 3 to 6 mm, posterior tibiofibular distance (PTFD) ranged from 1 to 3 mm, tibiofibular clear space (TFCS) ranged from 2 to 3 mm, and a Merle D'Aubigne ratio of 2:1 was observed in all ankles. When comparing the measurements obtained with those established by Harper and Keller, no statistically significant difference was found (2 < 5). CONCLUSION: with the use of the designed device, we achieved a correct and consistent radiographic image of the mortise and the distal tibiofibular syndesmosis.

INTRODUCCIÓN: las lesiones ligamentarias de la sindesmosis tibioperonea distal que ocasionan apertura de la misma son muy frecuentes en traumatología; sin embargo, su diagnóstico es un reto para el cirujano ortopedista. La radiografía de la mortaja tibioastragalina es el método más utilizado para el diagnóstico de este tipo de lesiones, pero es poco confiable ya que la posición del tobillo durante el estudio suele variar dependiendo del operador. OBJETIVO: demostrar que con el uso del dispositivo diseñado se logra una imagen radiográfica correcta y constante de la sindesmosis tibioperonea distal en la proyección de la mortaja. MATERIAL Y MÉTODOS: estudio prospectivo, longitudinal y observacional. Diseñamos un dispositivo de polipropileno que mantiene el tobillo a 90 grados de dorsiflexión y rotación interna de 15 grados. Aplicamos el dispositivo para tomar radiografías de la mortaja en tobillos sanos y les realizamos las mediciones correspondientes para valorar la sindesmosis. RESULTADOS: valoramos un total de 46 radiografías de tobillos sanos, con un predominio de tobillos izquierdos. Las mediciones conseguidas fueron las siguientes: espacio tibioperoneo (ETP) de 3 a 6 mm, la superposición tibioperonea (STP) de 1 a 3 mm, espacio astrágalo-tibial medial (EATM) de 2 a 3 mm y una relación de Merle D'Aubigne de 2:1 en todos los tobillos. Al comparar las mediciones obtenidas con las establecidas por Harper y Keller, no se encontró una diferencia estadísticamente significativa (2 < 5). CONCLUSIÓN: con el uso del dispositivo diseñado, obtuvimos una correcta y constante imagen radiográfica de la mortaja y la sindesmosis tibioperonea distal.

High Resolution MRI Confirms Torsional Injury as Mechanism for Combined Ankle and Common Fibular (Peroneal) Nerve Injuries.

Common fibular nerve (CFN) injury due to ankle fracture is an underreported complication. The authors have proposed that torsional injury to the ankle can be translated along the interosseous membrane (IOM), producing tension on the CFN at the fibular neck. A 23-year-old woman presented to our clinic for left foot drop. Three months prior, the patient sustained a fall with left ankle inversion injury while running. She was diagnosed with a minor ankle fracture and placed in an orthopaedic boot. Unfortunately, her swelling worsened and one week later the patient was diagnosed with foot drop, which was further corroborated with EMG studies showing severe CFN injury localizing to the fibular neck. Because of the lack of recovery, she underwent decompression of the CFN. She experienced immediate symptomatic relief. High resolution imaging in this case supports our previous mechanism for indirect trauma to the ankle resulting in CFN injury. (Journal of Surgical Orthopaedic Advances 33(1):053-055, 2024).

Diaphyseal giant cell tumour of mid-shaft tibia.

SummaryGiant cell tumours of bone are benign and locally aggressive tumours that usually occur in young adults and at the epiphysial locations after physeal closure. Occurrence outside of epiphysial locations and appearance in geriatric patients is rare. We report a case of a woman in her late 60s with a giant cell tumour of the mid-shaft of the right tibia. Extended curettage and biological reconstruction were performed with autologous double-barrel fibular struts and tri-cortical iliac crest bone grafting. At the 28-month follow-up examination, we noted full bony union at both ends with successful consolidation of the fibular struts, and importantly, no evidence of recurrence or other complications was observed.

Bone Age Determination of Epiphyseal Fusion at Knee Joint and Its Correlation with Chronological Age.

Background and Objectives: Bone age determination is a valuable method for forensic and disaster identifications of unknown human remains, as well as for medical and surgical procedural purposes. This retrospective research study aimed to determine the age based on epiphyseal fusion stages and investigate differences related to gender. Materials and Methods: X-rays of the knee were collected from medical imaging centers in hospitals in the south of Jordan and examined by two observers who determined the bone epiphyseal phase of closure for the femur, tibia, and fibula bone ends close to the knee based on a three-stage classification. Results: The main results revealed that females showed earlier epiphyseal union (Stage II) at the lower end of the femur and the upper ends of the tibia and fibula compared to males. In males, the start of complete union (Stage III) at knee bones was seen at the age of 17-18 years, while in females, it was seen at the age of 16-17 years. Additionally, knee bones showed complete union in 100% of males and females in the age groups 21-22 years and 20-21 years, respectively. Although females showed an earlier start and end of epiphyseal complete union than males, analysis of collected data showed no significant age differences between males and females at the three stages of epiphyseal union of the knee bones. Conclusions: Findings of the radiographic analysis of bone epiphyseal fusion at the knee joint are a helpful method for chronological age determination. This study supports the gender and ethnicity variation among different geographical locations. Studies with a high sample number would be needed to validate our findings.

Maisonneuve fracture treated with short leg cast: A case report with 41-month follow-up.

RATIONALE: Maisonneuve fracture is a specific type of severe ankle injury. To our current knowledge, once a Maisonneuve fracture is diagnosed, the surgery is always recommended for fear of sequelae from inaccurate joint reconstruction. However, in this case, we treated a Maisonneuve fracture with a short leg cast, and the 41-month follow-up showed a favorable outcome with no post-traumatic osteoarthritis, chronic pain, and instability. Therefore, this case provides evidence for the feasibility of conservative treatment of Maisonneuve fracture. PATIENT CONCERNS: A female patient in her early twenties sprained her left ankle while running, suffering regional pain, swelling, and limited mobility. DIAGNOSES: We diagnosed a Maisonneuve fracture with superior fibular fracture and Volkmann tuberosity fracture, a slight separation of inferior tibiofibular syndesmosis (ITS). INTERVENTIONS: The patient rejected our surgical recommendations in favor of nonsurgical treatment, in addition to refusing immobilization of the knee. Consequently, we had to treat her with a short leg cast for 8 weeks and asked her to return for regular follow-up visits. OUTCOMES: At the final follow-up, the radiography showed complete healing of proximal fibula fracture. The patient reported no discernible subjective differences between her bilateral ankles. The range of motion of the left ankle was measured at 22° of dorsiflexion and 40° of plantarflexion. Functional assessments using Olerud-Molander ankle scale and American Orthopedic Foot and Ankle Society Ankle-Hindfoot scale both scored 100 points. Additionally, the radiographic assessment classified arthritis as stage 0 according to Morrey-Wiedeman classification. LESSONS: To avoid missing and misdiagnosing, the physical examination should always extend to 2 neighboring joints. Secondly, if a Maisonneuve fracture is suspected, further computed tomography scans, radiography, and magnetic resonance imaging can help to determine the stability of the ITS and the integrity of the lateral collateral ligaments before making therapeutic decisions. Finally, considering the lateral collateral ligaments may remain intact, we recommend stabilizing ITS by repairing the medial ligaments, which can be conducted arthroscopically and be more minimally invasive, providing an elastic fixation that aligns better with the biomechanics of the ITS which is characterized as a micro-mobile rather than fully fixed joint.

A new and simple method for patellar height measurement: Fibula-condyle-patella angle.

OBJECTIVES: This study aims to evaluate the inter-observer reliability of fibula-condyle-patella angle measurements and to compare it with other measurement techniques. PATIENTS AND METHODS: Between January 01, 2023 and January 31, 2023, a total of 108 patients (20 males, 88 females; mean age: 47.5±12.0 years; range, 18 to 72 years) who underwent X-rays using the fibula-condyle-patella angle, Insall-Salvati, Caton-Deschamps, Blackburne-Pell, and plateau-patella angle (PPA) methods were retrospectively analyzed. Knee lateral radiographs taken in at least 30 degrees of flexion and appropriate rotation were scanned. All measurements were made by two orthopedic surgeons who were blinded to measurement methods. RESULTS: Right knee patellar height measurements were conducted in 56 patients, while left knee patellar heights were assessed in 52 patients. The highest inter-observer concordance was found in the fibula-condyle-patella angle. The second highest concordance was found in the Insall-Salvati. The highest concordance correlation was found with PPA in the measurements of both researchers. CONCLUSION: The fibula-condyle-patella angle is a reliable technique with a good inter-observer reliability for measuring patellar height. We believe that this study will inspire future research to establish comprehensive reference values for clinical applications.

Predicting Tibia-Fibula Geometry and Density From Anatomical Landmarks Via Statistical Appearance Model: Influence of Errors on Finite Element-Calculated Bone Strain.

State-of-the-art participant-specific finite element models require advanced medical imaging to quantify bone geometry and density distribution; access to and cost of imaging is prohibitive to the use of this approach. Statistical appearance models may enable estimation of participants' geometry and density in the absence of medical imaging. The purpose of this study was to: (1) quantify errors associated with predicting tibia-fibula geometry and density distribution from skin-mounted landmarks using a statistical appearance model and (2) quantify how those errors propagate to finite element-calculated bone strain. Participant-informed models of the tibia and fibula were generated for thirty participants from height and sex and from twelve skin-mounted landmarks using a statistical appearance model. Participant-specific running loads, calculated using gait data and a musculoskeletal model, were applied to participant-informed and CT-based models to predict bone strain using the finite element method. Participant-informed meshes illustrated median geometry and density distribution errors of 4.39-5.17 mm and 0.116-0.142 g/cm3, respectively, resulting in large errors in strain distribution (median RMSE = 476-492 µÎµ), peak strain (limits of agreement =±27-34%), and strained volume (limits of agreement =±104-202%). These findings indicate that neither skin-mounted landmark nor height and sex-based predictions could adequately approximate CT-derived participant-specific geometry, density distribution, or finite element-predicted bone strain and therefore should not be used for analyses comparing between groups or individuals.

The calcaneofibular ligament groove at the inferior fibula, an ultrasonographic anatomical landmark.

PURPOSE: Calcaneofibular ligament (CFL) injuries are harder to diagnose than anterior talofibular ligament (ATFL) ones. This study aimed to clarify the fibular attachment of the CFL and verify the bony landmark for evaluating the CFL on ultrasonography. METHODS: Fifty-nine ankles were used in this anatomical study. To confirm the control function of the CFL, we performed passive movement manually using cadaveric ankles and observed the ankle positions where the CFLs were tense. Histological observation of CFL attachment of the fibula was performed using Masson's trichrome stain. The ATFL and CFL were removed, and the bone morphology of the CFL attachment and inferior fibular end was imaged using a stereomicroscope and a 3D scanner. Using ultrasonography, we evaluated the bone morphology of the fibular attachment of the CFL in short-axis images of 27 healthy adult ankles. RESULTS: The CFL was tensed according to ankle motions: supination, maximum dorsi flexion, maximum plantar flexion, and mild plantar flexion-external rotation. Below the CFL attachment of the fibula was a slight groove between the inferior tip and the obscure tubercle of the fibula. This groove was observed in 81.5% of cases using short-axis ultrasonography. CONCLUSION: The CFL was tensed in various ankle positions to control the movements of the talocrural and subtalar joints. There was a slight groove at the inferior end of the fibula where the CFL coursed downward. We called it the CFL groove and proposed that it could serve as a landmark for the short-axis image of ultrasonography.

Pronounced cortical porosity and sex-specific patterns of increased bone and osteocyte lacunar mineralization characterize the human distal fibula with aging.

The high occurrence of distal fibula fractures among older women suggests a potential link to impaired bone health. Here we used a multiscale imaging approach to investigate the microarchitecture, mineralization, and biomechanics of the human distal fibula in relation to age and sex. Micro-computed tomography was performed to analyze the local volumetric bone mineral density and various microarchitectural parameters of the trabecular and the cortical compartment. Bone mineral density distribution and osteocyte lacunar parameters were quantified using quantitative backscattered electron imaging in periosteal, endocortical, and trabecular regions. Additionally, cortical hardness and Young's modulus were assessed by nanoindentation. While cortical porosity strongly increased with age independent of sex, trabecular microarchitecture remained stable. Notably, nearly half of the specimens showed non-bony hypermineralized tissue located at the periosteum, similar to that previously detected in the femoral neck, with no consistent association with advanced age. Independent of this finding, cortical and trabecular mineralization, i.e., mean calcium content, as well as endocortical tissue hardness increased with age in males but not females. Importantly, we also observed mineralized osteocyte lacunae that increased with age specifically in females. In conclusion, our results indicate that skeletal aging of the distal fibula is signified not only by pronounced cortical porosity but also by an increase in mineralized osteocyte lacunae in females. These findings may provide an explanation for the increased occurrence of ankle fractures in older women.

Fibular morphology is not associated with incidence of peroneal tendon dislocation.

PURPOSE: The association of peroneal tendon dislocation with peroneal bone morphology and postoperative redislocation rates remains unknown. This study compared the fibula morphology in patients with peroneal tendon dislocation with that in a control population. METHODS: The study enrolled 48 patients who underwent surgery for peroneal tendon dislocation at our institution during between 2018 and 2023. Thirty-five patients with preoperative magnetic resonance imaging of the ankle were defined as Group D and 35 with magnetic resonance imaging of the ankle for other reasons and with similar background data were selected as the control group (Group C). The posterior tilting angle of the fibula, posterolateral angle and posterolateral edge angle were evaluated at the plafond level. The posterior tilting angle, posterolateral angle and retromalleolar bone shape according to the Rosenberg classification (flat, convex, concave) were evaluated at the midpoint between the plafond and the tip. RESULTS: At the plafond level, the posterior tilting, posterolateral and posterolateral edge angles were 57.7 ± 11.1°, 123.8 ± 12.3° and 90.8 ± 13.7°, respectively, in Group D and 64.1 ± 15.4°, 121.1 ± 12.3° and 88.7 ± 12.2°, respectively, in Group C, with no significant differences. No significant between-group differences existed in the posterior tilting and posterolateral angles at the midpoint level. Moreover, no significant differences existed in distribution of the bone geometry according to the Rosenberg classification. CONCLUSION: There were no differences in morphology between patients with peroneal tendon dislocation and controls. This study provides useful information on the indications for primary surgery and whether bony approach is useful for peroneal tendon dislocation. LEVEL OF EVIDENCE: Level IV.

An imageology-based feasibility study of plating posterolateral tibial plateau fractures via an anterolateral trans-fibular-head approach.

BACKGROUND: There are many difficulties in the reduction and fixation of the tibial plateau fractures involving posterolateral quadrant using general plates via traditional approaches. By imaging the area above the fibulae capitulum, this study was performed to investigate the feasibility of the trans-fibular-head approach and to design an ideal anatomical plate. METHODS: MRI and CT scans of the knee joint were collected from 205 healthy volunteers (103 males, 102 females). Gender and height were used to divide the volunteers into groups separately: (1) A1 group and A2 group according to gender, (2) B1 group and B2 group according to height. Based on the images, several parameters were defined and measured to describe the space above the head of the fibula. In addition, differences in these parameters between genders and height were compared. RESULTS: The narrowest distance in the bony region was (10.96 ± 1.39) mm, (5.41 ± 0.97 mm) in the bone-ligament region. The narrowest distance of bony region in the A1 group was more than that in the A2 group (11.21 ± 1.62 mm, 10.85 ± 1.47 mm, p = 0.029). The narrowest distance of the bony region was (10.21 ± 1.42) mm and (11.65 ± 1.39) mm in the B1 group and B2 group, respectively (p = 0.002). The narrowest distance of the bone-ligament region was (5.39 ± 0.78) mm and (5.22 ± 1.21) mm in the A1 group and A2 group, respectively. No statistically significant differences were observed between the A1 group and the A2 group in terms of the narrowest distance of the bone-ligament region. In the B1 group, the narrowest distance of the bone-ligament region (5.18 ± 0.71 mm) was not significantly less than that (5.31 ± 0.91 mm) in the B2 group. CONCLUSION: The space above the fibular capitellum was ample enough to place the plate for treating tibial plateau fractures involving posterolateral quadrant. The divisions of the lateral tibial plateau by 3-dimensional CT and the parameters of each region were crucial for providing guidance for designing the anatomical plate for the trans-fibular-head approach.

Image Rotation Alters Apparent Fibula Length: An Evaluation of Talocrural Angle, Shenton Line, and Dime Sign.

BACKGROUND: Fibula shortening can compromise ankle stability and force transmission, thereby impacting clinical outcomes. Because radiographs depict 3-dimensional anatomy in 2 dimensions, accurate radiographic assessment of fibula length is a commonly encountered clinical challenge. The talocrural angle (TCA), Shenton line, and dime sign are useful parameters of fibula length. Yet, the impact of 3-dimensional limb positioning on these radiographic parameters is not established. METHODS: Bone models were constructed from CT scans of 30 lower limbs. Fibula length was computationally manipulated, and digitally reconstructed radiographs were generated reflecting 1-degree increments of sagittal and axial plane rotation of each limb for each fibula length condition. The TCA was computationally measured on each image. The presence of an aligned mortise view, intact Shenton line, and intact dime sign was assessed by 2 observers. RESULTS: The mean TCA, which was 78.0 (95% CI ± 1.6) degrees for a true mortise projection with anatomic fibula length, changed by approximately 1 degree per millimeter of fibula length change. On average, 14.7 degrees of caudal rotation obscured 2 mm of fibular shortening by virtue of producing the same TCA as a true mortise view with anatomic fibula length, designated a false positive view. Axial rotation had a comparatively small effect. Observers 1 and 2 were, respectively, 91% and 88% less likely to accurately judge the image alignment of the false positive images compared to true mortise images. Moreover, intraobserver agreement was poor to moderate (mean 0.47, range 0.13-0.59) and interobserver agreement was uniformly poor (mean 0.08, range 0.01-0.20). CONCLUSION: In our study using digitally reconstructed radiographs from CT scans of 30 limbs, we found that sagittal plane rotation impacts the radiographic appearance of fibula length as measured by the TCA. Limb axial rotation had a comparatively small effect. Further study of human perception of Shenton line and dime sign is needed before the effect of rotation on these parameters can be fully understood. LEVEL OF EVIDENCE: Level IV, case series.

Pachydysostosis of the fibula in a case of familial adenomatous polyposis.

BACKGROUND: Familial Adenomatous Polyposis (FAP) is a colorectal cancer (CRC) predisposition syndrome caused by germline APC mutations and characterised by an increased risk of CRC and colonic polyps and, in certain forms, of specific prominent extraintestinal manifestations, namely osteomas, soft tissue tumours and dental anomalies. Pachydysostosis of the fibula is a rare clinical entity defined by unilateral bowing of the distal portion of the fibula and elongation of the entire bone, without affectation of the tibia. CLINICAL REPORT: We report a 17-year-old male, who presented with a non-progressive bowing of the right leg detected at 18 months of age caused by a fibula malformation (later characterized as pachydysostosis) and a large exophytic osteoma of the left radius, noticed at the age of 15 years, without gastrointestinal symptoms. There was no relevant family history. Detailed characterisation revealed multiple osteomas, skin lesions and dental abnormalities, raising the hypothesis of FAP. This diagnosis was confirmed by genetic testing [c.4406_4409dup p.(Ala1471Serfs*17) de novo mutation in the APC gene] and endoscopic investigation (multiple adenomas throughout the colon, ileum and stomach). DISCUSSION: This case report draws attention to the phenotypic spectrum of skeletal manifestations of FAP: this patient has a congenital fibula malformation, not previously associated with this syndrome, but which is likely to have been its first manifestation in this patient. This clinical case also illustrates the challenges in the early diagnosis of FAP, especially without family history, and highlights the importance of a multidisciplinary approach and the adequate study of rare skeletal abnormalities.

Ultrasound Assessment of Ankle Syndesmotic Injuries in a Pediatric Population.

OBJECTIVE: To determine sensitivity and specificity for anterior-inferior tibiofibular ligament (AiTFL) integrity and tibiofibular clear-space (TFCS) cut-off points for dynamic evaluation using ultrasound (US) in a pediatric population. DESIGN: Prospective cohort study. SETTING: Tertiary care university-affiliated pediatric hospital patients between the ages of 12 and 18 sustaining acute ankle trauma with syndesmotic injury. INTERVENTIONS: Participants were assigned to the syndesmotic injury protocol that included a standardized MRI and US. MAIN OUTCOME MEASURES: Anterior-inferior tibiofibular ligament integrity for static assessment and TFCS measurements for dynamic assessment on US. For dynamic assessment, the distance between the distal tibia and fibula was first measured in neutral position and then in external rotation for each ankle. The US results on AiTFL integrity were compared with MRI, considered as our gold standard. Optimal cut-off points of TFCS values were determined with receiver operating characteristics curve analysis. RESULTS: Twenty-six participants were included. Mean age was 14.8 years (SD = 1.3 years). Sensitivity and specificity for AiTFL integrity were 79% and 100%, respectively (4 false negatives on partial tears). For dynamic assessment, the cut-off points for the differences in tibiofibular distance between the 2 ankles in 1) neutral position (TFCS N I-U ) and 2) external rotation (TFCS ER I-U ) were 0.2 mm (sensitivity = 83% and specificity = 80%) and 0.1 mm (sensitivity = 83% and specificity = 80%), respectively. CONCLUSIONS: Static US could be used in a triage context as a diagnostic tool for AiTFL integrity in a pediatric population as it shows good sensitivity and excellent specificity.