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.

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.

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%.

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.

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.

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.

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).

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.

Proximal fibular physeal stress injury: a known entity in an unusual location.

In the skeletally immature patient, physeal stress injury is a common diagnosis in repetitive stress injury; in this case, we present an atypical location of physeal stress injury of the bilateral proximal fibulae. There are multiple well-documented diagnoses of physeal stress injury involving the shoulder, elbow, wrist and tibia, often considered when patients present with the typical history of intensive sports training and pain exacerbated by repetitive movements. However, isolated proximal fibular physeal stress injury is either unusual or under-recognized and underreported. Although less common, proximal fibular physeal stress injury should be among the diagnostic considerations in active adolescents complaining of lower extremity pain as failure to identify this entity can lead to delayed care and preventable potential long-term musculoskeletal effects.

The lowest point of fibula (LPF) could be used as a reliable bony landmark for arthroscopic anchor placement of lateral ankle ligaments ----compared with open Broström procedure.

BACKGROUND: Arthroscopic technique procedures was wide accepted for the treatment of chronic ankle instability (CAI). But little acknowledge was involved to the bony landmarks and anatomic features of different bundles of lateral ligaments under arthroscopic view. METHODS: Sixty patients with acute or chronic lateral ankle ligaments injury (LAI) were collected prospectively, and divided randomly into two groups. In arthroscopic group, the bone tunnels were made on the LPF arthroscopically. And in open group, the bone tunnels were made on the Fibular obscure tubercle (FOT) in open procedure. The inferior bundle of ATFL and Arcuate fibre was also identified reference to the LPF and labeled by a PDS II suture penetration. Following that, The distances of the bone tunnels to the different bony markers were measured and compare between two groups. The penetrating locations of PDS II on the inferior bundle of ATFL and Arcuate fibre were also confirmed intraoperatively. And the safe angle of anchor implantation on the axial view was measured on postoperative CT scan. RESULTS: The distances of bone tunnel to the fibular tip, the fibular insertion of anterior-inferior tibiofibular ligament (AITFL), and the FOT in arthroscopic and open locating groups were 4.9 ± 2.2 and 6.3 ± 2.2 mm, 13.5 ± 2.7 and 12.4 ± 1.1 mm, 5.8 ± 2.2 and 5.6 ± 1.0 mm, respectively. The distances of bone tunnels to the FOT and fibular tip on 3d-CT view was 4.4 ± 1.5 and 4.6 ± 0.9 mm, 14.4 ± 3.2 and 13.2 ± 1.8 mm in arthroscopic and open group, and there were no significant differences between two groups. The safe angle of arthroscopic anchor placement on the axial plan was ranged from 24.9 ± 6.3o to 58.1 ± 8.0o. The PDS II sutures penetrating on the inferior bundles of ATFL and the arciform fibres were also comfirmed successfully by open visualizaion.The average distance of penetration point to the horizontal line cross the fibular tip was 2.3 ± 2.7 mm (ranged from - 3.1 to 6.0 mm), and to the vertical line cross the FOT was 2.7 ± 2.7 mm (ranged from - 2.5 to 7.5 mm). CONCLUSION: Take the lowest point of fibula under arthroscopy (LPF) as a bony reference, we could identify the iATFL under arthroscopic visualization. By this way, we could place the suture anchors properly to the fibular footprint and suture the iATFL fibres successfully.

Comparison of different fibula procedures in tibiotalocalcaneal arthrodesis with a retrograde intramedullary nail: a mid-term retrospective study.

BACKGROUND: Tibiotalocalcaneal (TTC) arthrodesis with a retrograde intramedullary nail for severe tibiotalar and talocalcaneal arthritis has a high fusion rate; however, no studies have focused on how to handle the fibula intraoperatively to achieve better results. This study aimed to compare the efficacies of various fibular procedures. METHODS: We retrospectively reviewed the cases of severe tibiotalar and talocalcaneal arthritis in adults treated with TTC arthrodesis using a retrograde intramedullary nail between January 2012 and July 2017. The patients were divided into three groups according to different fibular procedures: Fibular osteotomy (FO), fibular strut (FS), and fibular preservation (FP). Functional outcomes and pain were assessed using the American Orthopedic Foot and Ankle Society (AOFAS) ankle and hindfoot score and visual analog scales (VAS), respectively. The operation time, fusion time, radiographic evaluation, and complications were also recorded. RESULTS: Fifty-eight patients with an average age of 53.2 (range, 32-69) years were enrolled in the final analysis. The numbers of patients enrolled in the three groups were 21, 19, and 18 in the FO, FS, and FP groups, respectively. The mean postoperative follow-up time was 66.0 (range, 60-78) months. All groups showed a high fusion rate (90.5% for FO, 94.7% for FS, and 94.4% for FP) and significant improvement in AOFAS ankle and hindfoot scores and VAS scores at the latest follow-up. There were no significant differences in these parameters among the three groups. The mean operation time of FS (131.3 ± 17.1 min) was longer than that of FO (119.3 ± 11.7 min) and FS (112.2 ± 12.6 min), but the fusion time was shorter (15.1 ± 2.8 weeks for FS, 17.2 ± 1.9 weeks for FO, and 16.8 ± 1.9 weeks for FP). Statistically significant differences were observed in these parameters. CONCLUSIONS: TTC arthrodesis using a retrograde intramedullary nail is an effective procedure with a high rate of fusion to treat severe tibiotalar and talocalcaneal arthritis in adults; however, FSs can shorten fusion time when compared with FO and FP. LEVEL OF CLINICAL EVIDENCE: Level 3.

Reconstruction of complicated spinal tuberculosis with long-segment fibula transplantation: a case report.

BACKGROUND: Treating complex cases of spinal tuberculosis (STB) that involve multiple vertebral bodies and cause destruction of the spinal structure, kyphotic deformity, and acute nerve injury can be challenging. This report describes the course of treatment and 5-year follow-up of a complex case of multisegmental STB. CASE PRESENTATION: This report describes a case of tuberculosis affecting the vertebrae extending from thoracic 12 to lumbar 5 in a 60-year-old woman who suffered sudden paralysis in both lower extremities. The patient underwent emergency posterior paraspinal abscess clearance, laminectomy with spinal decompression. Partial correction of the kyphotic deformity via long-segment fixation from the T9 vertebral body to the ilium in a one-stage posterior procedure. The patient's neurological status was diagnosed as grade E on the American Spinal Injury Association (ASIA) scale after the one-stage operation. Following standardized 4-combination anti-tuberculosis drug therapy for three months in postoperative patients, the patient underwent two-stage transabdominal anterior abscess removal, partial debridement of the lesion and bilateral fibula graft support. One year after the two-stage operation, the patient's visual analog scale (VAS) score of back pain was 1 point, and the patient's erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels returned to normal. Five years after the second-stage operation, the Oswestry disability index (ODI) of patient quality of life was 14 points. There was a 4-degree change in the Cobb angle over five years. During the five-year follow-up period, the grafted fibula did not experience any subsidence. CONCLUSION: For patients with spinal tuberculosis and acute paralysis, it is essential to relieve spinal cord compression as soon as possible to recover spinal cord function. For lesions that cannot be debrided entirely, although limited debridement combined with anti-tuberculosis drug therapy has the risk of sinus formation and tuberculosis recurrence, it is much safer than the risk of thorough debridement surgery. In this case, an unconventional long-segment fibula graft, pelvis-vertebral support, was an effective reconstruction method.

A Young Skier with Leg Pain.

BACKGROUND: Proximal tibiofibular joint (PTFJ) dislocation is a rare injury that can disrupt the proximal tibia-fibula joint. The abnormalities in knee x-ray imaging can be subtle and difficult to detect, requiring careful assessment. This rare cause of lateral knee pain requires a high level of suspicion for diagnosis. Treatment is closed reduction; unstable PTFJ dislocations often require surgical intervention. CASE REPORT: A 17-year-old young man presented to the emergency department (ED) with right lateral knee pain and difficulty walking after colliding with another skier 2 days prior. The examination showed right lateral ecchymosis and tenderness over the lateral proximal fibula. He remained neurovascularly intact with a full passive and active range of motion. X-ray studies were obtained. The patient was referred by his outpatient orthopedic surgeon after the initial knee x-ray study was concerning for PTFJ dislocation and unsuccessful reduction. In the ED, the patient underwent moderate sedation and successful orthopedic-guided reduction via medial force on the lateral fibular head, while hyper-flexing the knee and holding the foot dorsiflexed and everted. Post-reduction radiographs showed improved proximal tibiofibular alignment without fracture. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: PTFJ dislocation is a rare injury that can be missed easily and requires a high level of suspicion when presented with an acute traumatic knee pain. Closed reduction of PTFJ dislocation can be achieved in the ED and early identification can prevent long-term sequelae.

Expanding the digital workflow for a prefabricated prelaminated fibula flap: A dental technique.

The workflow for a prefabricated prelaminated fibula free flap has been almost entirely digitized. One of the last 2 remaining steps is the impression making in stage 1 surgery. This article describes a novel computed-tomography based digital scanning technique with an assessment of the resultant accuracy.

Lateral malleolar crest and its clinical importance.

PURPOSE: During study of anatomy of a fractured posterior malleolus of the ankle on CT scans, the authors noticed a prominent crest on the lateral malleolus, which they termed the lateral malleolar crest (LMC). As, in their view, LMC is a clinically important structure which was only briefly mentioned by a few authors without an official term, they focused on the anatomy of this structure. MATERIALS AND METHODS: A total of 352 dry fibulae were analyzed and the following parameters recorded: (F) length of the fibula, (LMC) total length of LMC, (A) length of the part of the examined crest from the superior border of the articular facet of the lateral malleolus (AFLM) to its most proximal intersection with the midline of the fibula, (B) height of the medial triangular rough surface, and (A/F) A/F ratio. RESULTS: The crest was observed in all specimens. (F) was 346.5 ± 26 mm (95% confidence interval [CI] 344-349), (LMC) was 85.4 ± 11.6 mm (95% CI 84.2-86.6), (A/F) was 25% ± 3% (95% CI 24.7-25.3) in the whole group. (A) was 25.9 ± 6.5 mm (95% CI 24.8-26.8) in the whole group, (B) was 34.9 ± 4.7 mm (95% CI 34.3-35.5) in the whole group, 36 ± 6.1 mm (95% CI 35.1-36.9). CONCLUSION: LMC is an important structure on the lateral malleolus. The knowledge of its anatomy is essential for placement of syndesmotic screws or/and the fibular plate.

The Relationship Between Fibular Notch Anatomy and ATFL Rupture.

The anterior talofibular ligament (ATFL) is the first to be damaged during a lateral ankle sprain. Dynamic and static structures have been investigated to better understand ATFL rupture, but the predisposing factors have not been fully elucidated. This study aims to define the fibular notch version that can evaluate the position of the fibular notch relative to the tibia and investigate the relationship between the fibular notch version (FNV) and ATFL rupture. This study included 71 patients with isolated ATFL rupture diagnosed clinically and radiologically and 71 control patients without any foot or ankle pathologies. Anterior facet length (AFL), posterior facet length (PFL), anterior-posterior facet angle (APFA), fibular notch depth (ND), and FNV measurements were performed on axial magnetic resonance images (MRI). We defined FNV as a parameter that evaluates the fibular notch's relative position to the distal tibia. The mean FNV was 16.6° ± 4.9° in patients with ATFL rupture and 12.4° ± 5.6° in the control group; when both groups were compared, FNV measurements were significantly higher in patients with ATFL rupture (p = .002). The mean APFA was 123.9° ± 10° in the group with ATFL rupture and 129.7° ± 7.8° in the control group. When both groups were compared, APFA was significantly lower in patients with ATFL rupture (p = .014). There was no significant difference between the groups regarding AFL, PFL, and ND. A more posterior (retroverted) fibular notch and a lower fibular notch angle seem to be associated with higher rates of ATFL rupture.

[Radiographic diagnosis of distal fibula avulsion fractures: Comparison of ankle X-ray and three-dimensional reconstruction of CT].

OBJECTIVE: To investigate the difference in sensitivity between X-ray and three-dimensional reconstruction of computed tomography (3D-CT) for the diagnosis of distal fibular avulsion fracture, and the radiographic presentation of the ossicle. METHODS: From January to October 2018, 92 patients with distal fibular avulsion fracture were visited for surgical treatment in Department of Sports Medicine, Peking University Third Hospital, and 60 cases were finally enrolled according to the inclusion and exclusion criteria. Intraoperative detection was regarded as the gold standard, and the diagnostic sensitivity of preoperative ankle X-ray and 3D-CT for the distal fibular avulsion fractures was statistically determined. The ossicle maximum diameter as well as the degree of its displacement were also measured. On 3D-CT, the distance from the ossicle center point to the anterior fibular tuberosity (a), the distance to the fibular tip (b), and the a/b value was used to present the ossicle displacement. RESULTS: Among the 60 patients, 36 and the 52 patients were correctly detected by X-ray and 3D-CT, respectively, and the sensitivities was 60.0% and 86.7%, respectively (P=0.004). The mean diameter of the ossicle on X-ray and 3D-CT was (9.2±3.9) mm and (10.5±3.2) mm, respectively. The mean distance from the ossicle center to the anterior fibular tuberosity (a) was (17.5±3.6) mm and the mean distance to the fibular tip (b) was (17.4±4.8) mm, with mean a/b values of 1.1±0.7. The intraclass correlation coefficients (ICC) for each measurement ranged from 0.891-0.998 with a high degree of consistency. CONCLUSION: Compared with X-ray, 3D-CT has higher sensitivity in diagnosing distal fibular avulsion fractures, can help clinicians evaluate ossicle's location and choose surgical methods, and is recommended to be performed in patients with suspected distal fibula avulsion fractures in clinical practice.

What is the best treatment for syndesmosis fixation? Suture-button or syndesmotic screw ? Bilateral CT-based early postoperative analysis.

BACKGROUND: The aim of this study was to compare the effectiveness of syndesmotic screw (SS) and suture button (SB) on the reduction and fixation of syndesmosis via early postoperative bilateral computed tomography (CT). METHODS: This single-center retrospective study included 76 patients aged ≥ 18 years with a unilateral syndesmosis injury. SS was applied to 40 patients and SB to 36 patients. The differences between the sides stabilized using SB or SS and the intact sides were analyzed using the parameters of tibio-fibular clear space (∆CS) and anterior or posterior sagittal translation (∆ST) depending on the orientation of the fibula. The cases in which the fibula was translocated to the posterior of the tibia after the change of ∆ST and ∆CS> 2 mm were evaluated as malreduction. Axial CT images taken from the level of syndesmosis fixation were divided into 4 zones according to the orientation angle of the implant sent from the fibula to the tibia. RESULTS: No significant difference was found in the analyses performed between total patient group with malreduction and fixation groups in terms of ∆CS and ∆ST values (p = 0.708, p = 0.289). It was observed that the fixation material was in zone 3 in 54 patients and in zone 2 in 22 patients. No significant difference was found in the analyses performed between the SS and SB groups according to the implant zone (p = 0.191). In the SS group sent from Zone 2, the malreduction rate according to the ∆ST value of syndesmosis was found to be significantly higher than in the SB group (p = 0.008, p = 0.003). CONCLUSION: When the implant is applied with the correct technique, there is no difference between SS and SB in terms of early postoperative reduction. When the SS is advanced at an inappropriate angle, it negatively affects the reduction of the fibula, while SB can better tolerate angle errors up to certain degrees due to its flexible structure. Therefore, it can be presumed that the suture button system is a more convenient method in the reduction and fixation of syndesmosis than the syndesmotic screw. LEVEL OF EVIDENCE: Level IV.

Maisonneuve ankle fracture.

Maisonneuve fracture (MF) is defined as an ankle fracture-dislocation associated always with a fracture of the proximal quarter of the fibula and rupture of the anterior and interosseous tibiofibular ligaments. Other injuries are variable. Recent CT studies have demonstrated that MF is a far more complex injury than initially supposed. Therefore it is necessary to change substantially the current concepts related to this issue. MF is combined in about 80% of cases with a fracture of the posterior malleolus and also with malposition of the distal fibula in the fibular notch. An exact assessment of these injuries requires post-injury CT examination which should be used as a standard in MFs. The main goal of treatment is anatomical reduction of the distal fibula into the fibular notch. In case of avulsion of a larger fragment of the posterior malleolus, it is necessary to perform as the first step its reduction and fixation from the posterolateral approach and thus restore integrity of the notch. Closed reduction of the distal fibula is associated with malposition in up to 50% of cases and therefore open reduction from a short anterolateral approach is preferred. Accuracy of reduction should be always checked by postoperative CT scan.

Can CT-based assessment of lateral malleolus anatomy indicate when and how to perform an intramedullary fixation in distal fibula fractures? An analysis of 150 ankles.

PURPOSE: The primary aim was to analyse the lateral malleolus morphology with a focus on the shape of the distal fibula for IM fixation of the fibula in infra- and transsyndesmotic fracture patterns. The secondary aim was to propose a treatment algorithm according to the lateral malleolar anatomy. METHODS: 77 healthy, skeletally mature volunteers underwent CT scanning of the ankle. The fibula medullary canal and its cortical thickness were quantitatively analysed at 4 different levels measured from the fibular tip (1.5 cm, 3.0 cm, 4.5 cm, and 6.0 cm). A geometric classification was proposed, and a decision algorithm was developed. Statistical significance was set at a p-value < 0.05. RESULTS: The smallest diameter of the medullary canal of the fibula was at 6.0 cm from the tip of the fibula, in 98.2% of the ankles. The distal fibula can be classified into triangular and rectangular type, according to the cortical thickness index (p < 0.0001). In 16.7% ankles, the internal diameter of the fibula at 6.0 cm was equal or narrower than 3.5 mm (p < 0.05). CONCLUSION: The shape of the distal fibula as evaluated by CT-guided analysis allows for IM osteosynthesis of the lateral malleolus in 83% of individuals. In our study, the smallest diameter of the medullary canal of the fibula was located 6.0 cm from the tip of the lateral malleolus. Coronal CT evaluation is advantageous in indicating which type of IM implant should be used safely for infra- and transsyndesmotic fracture patterns, potentially reducing intraoperative risks.