Computed tomography-based morphometric analysis of normal distal tibiofibular syndesmosis in the Indian population.

BACKGROUND: In suspected Ankle Instability, the parameters that can be defined in the X-ray have their limitation owing to their variability in positioning and rotation of the tibiofibular joint. This inaccuracy further increases due to variability in morphometric parameters of distal tibiofibular syndesmosis among different populations based on race and sex. This research aims to study morphometry of normal distal tibiofibular syndesmosis based on computed tomography imaging in the Indian population. METHODS: An Prospective observational study was performed from December 2020 to October 2022 on normal ankle CT scans of 100 Indian population using axial, sagittal, and coronal CT images. Anterior and posterior tibiofibular distance, Morphology of the incisura fibularis based on depth, Tibiofibular clear space (TFCS) and tibiofibular overlap (TFO), Transverse and longitudinal length of the fibula, and Relationship between the center of the talus and the center of a line joining the outer aspect of malleoli in the coronal plane were measured and analyzed by two different observers. RESULTS: Out of the 100 participants, 77 (77 %) were male, and 23 (23 %) were female. The overall mean age of participants was 34.69 ± 9.7 years. The incisura fibularis was concave in 54 %, and shallow in 46 %. Anterior tibiofibular distance, Posterior tibiofibular distance, and Tibiofibular overlap were significantly different in comparison to the male with female populations (p-value < 0.05). CONCLUSION: This study gives the indices that describe normal variations in the anatomical relationship between the fibula and fibular incisure in the Indian population, which will be helpful for improving the diagnostic accuracy of distal tibiofibular syndesmoses and providing optimal treatment in order to improve functional outcomes and reduce the risk of complications. LEVEL OF EVIDENCE: III.

[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.

Standing on single foot-binding test yields satisfactory results as a novel method for the diagnosis of distal tibiofibular syndesmosis instability: a prospective, cross-sectional diagnostic-accuracy study.

BACKGROUND: Non-invasive diagnosis of distal tibiofibular syndesmosis instability (DTSI) was a great challenge to clinicians. We designed a new method, the Standing on single foot-Binding test, and investigated the accuracy of the test in the diagnosis of distal tibiofibular syndesmosis instability in adults with a history of ankle injury. METHODS: 85 participants with ankle injury were subjected to the Standing on single foot-Binding test, MRI and palpation to detect the distal tibiofibular syndesmosis instability (DTSI) and the findings were compared with ankle arthroscopic results. Both participants and arthroscopist were blind to the predicted results of the clinical tests. Sensitivity, specificity, PPV, NPV, LR+, LR - and their 95% CIs were calculated for each of the clinical tests as well as for the positive clinical diagnosis. RESULTS: The Standing on single foot-Binding test (SOSF-B test) outperformed MRI and palpation, in terms of sensitivity (87.5%/84.38%), specificity (86.79%/86.79%), PPV (80%/79.41%), NPV (92%/91.2%), LR+ (6.625/6.39), LR- (0.14/0.18) and diagnostic accuracy (87.06/85.88), among others, in the diagnosis of distal tibiofibular syndesmosis instability (DTSI). The diagnostic performance of 20° SOSF-B test was virtually identical to that of 0° SOSF-B test. According to the prevalence (28.7%) of DTSI and LR of four tests, the post-test probability could be used in clinical practice for the prediction of DTSI. CONCLUSION: This prospective and double-blind diagnostic test showed that the SOSF-B test is clinically feasible for the diagnosis of distal tibiofibular syndesmosis instability (DTSI), and new diagnostic tools for rapid screening of distal tibiofibular syndesmosis instability (DTSI). LEVEL OF EVIDENCE: II.

The distal tibiofibular joint effusion may be a reliable index for diagnosing the distal tibiofibular syndesmosis instability in ankle.

PURPOSE: To analyze the accuracy of MRI in diagnosis of distal tibiofibular syndesmosis instability (DTSI) and construct new diagnostic parameters. MATERIALS AND METHODS: This retrospective study evaluated 212 patients with history of ankle sprains and 3 T MRI and received a final diagnosis of distal tibiofibular syndesmosis instability by ankle arthroscopic surgery from October 2017 and December 2021. We compared the accuracy of syndesmotic injury, qualitative index of distal tibiofibular joint effusion (DTJE), and quantitative index of distal tibiofibular joint effusion (DTJE) in diagnosing distal tibiofibular syndesmosis instability. The criteria for syndesmotic injury were consistent with previous literature, and DTJE was grouped according to the pre-experimental results. RESULTS: A total of 212 patients (mean age, 35.64 ± 11.79, 74 female and 138 male) were included. Independent predictive MRI features included syndesmotic injury, qualitative index of distal tibiofibular joint effusion, and quantitative index of DTJE including the height, projected area of equal-point method, and projected area of incremental-value method. The quantitative index of DTJE showed a higher area under the receiver operating characteristic curve (0.805/0.803/0.804/0.811/0.817/0.805 > 0.8, P < 0.05; in comparison with all other method). The height measurement method was simpler and easier to operate, that could be gotten only by measuring the DTJE distance of a MRI independent layer, and the cut-off value of the effusion height was 8.00 mm and the Youden index (0.56) was the best. CONCLUSIONS: Our research translated a complicated string of MRI multi-dimensional spatial measurements into a simple measuring process, and established the significance of quantifying DTJE in the diagnosis of DTSI. We found that the 8-mm height of DTJE was a more specific indicator for DTSI and could serve as a novel MRI diagnostic cutoff in clinical practice.

The distal tibiofibular syndesmosis is a reliable landmark for 3° varus tibial resection in total knee arthroplasty: a radiological evaluation on 1296 cases.

PURPOSE: The purpose of this study was to evaluate the reproducibility and the accuracy of distal tibiofibular syndesmosis (DTFS) as landmark to perform controlled varus tibial resections during total knee arthroplasty (TKA). The hypothesis was that DTFS can be used to perform an accurate 3° varus tibial cut. METHODS: A retrospective analysis on a consecutive series of standard weightbearing full-length anteroposterior views of the lower limbs radiographic images was conducted. For each radiograph, the hip-knee-ankle (HKA) angle, the angle between the tibial mechanical axis and the line connecting the centre of the tibial spines and the DTFS (tibiofibular angle, TFA) and the medial proximal tibial angle (MPTA) were calculated. Each measurement was carried out twice by three independent observers, and intra- and inter-observer measurement reliability were assessed using the intraclass correlation coefficient (ICC) analysis. RESULTS: A total of 1296 lower limbs were analysed from a series of 648 weightbearing full-length anteroposterior radiographs. The ICC were > 90% for all measurements. The mean TFA value was 2.94 ± 0.68 (range 2.38-3.51). No differences were detected comparing the mean TFA value on the right and left limb (p = 0.795) as well as comparing the values in male and female patients (p = 0.691). Linear regression analysis did not find statistically significant correlation between TFA and MPTA, or TFA and HKA angles, respectively. CONCLUSION: The distal tibiofibular syndesmosis is a reliable and easy reproducible radiographic landmark that can be used when planning a 3° varus tibial cut. Future studies are needed to confirm the validity of this method also in clinical settings. LEVEL OF EVIDENCE: IV, retrospective case series.

Distal tibiofibular syndesmosis fibular notch typing and its clinical significance based on CT / 解剖学报

Objective To investigate the morphological typing and clinical significance of the distal tibiofibular syndesmosis fibular notch based on CT images. Methods According to the inclusion and exclusion ceiteria‚ the imaging data of patients undergoing ankle joint CT examination were analyzed‚ and the inferior tibiofibular joint fibula notch was classified according to the morphological characteristics. The measurements included 8 distances. There were 123 males and 102 females‚ all of whom were Han nationality‚ aged 18-60 years old. Results Retrospectively analyzed the result of 225 patients from December 2013 to December 2022. The distal tibiofibular syndesmosis fibular notch was divided into four types according to morphological characteristics‚ C-shaped (50. 67%)‚ V-shaped (26. 67%)‚ flat-shaped (15. 11%) and L-shaped (7. 56%). The angle between the anterior and posterior facets of the flat shape (145. 56 ± 9. 25)° was the largest and the angle between the anterior and posterior facets of the L shape (125. 07 ± 13. 54)° was the smallest(P< 0. 05); the depth of the notch in the flat shape (3. 11 ± 0. 83) mm was the smallest and in the L shape (4. 47±1. 11) mm was the largest(P<0. 05);The posterior facet length (13. 06 ± 3. 56) mm and anterior tibiofibular gap (3. 83±1. 49) mm on left were larger than on the right side (P<0. 05); The posterior facet length (13. 36 ± 3. 46) mm‚ fibular notch depth (3. 93 ± 1. 10) mm and vertical distance of tibiofibular overlap (9. 10 ± 2. 55) mm larger in men than in women (P<0. 05). Conclusion In this study‚ the data related to the inferior tibiofibular syndesmosis notch were measured and divided into four types according to the shape. The flat inferior tibiofibular syndesmosis notch is more likely to have chronic ankle instability‚ and the fibula is more likely to move forward during anatomical reduction. The inferior tibiofibular syndesmosis of L-shaped and C-shaped notches is more prone to posterior displacement of fibula or poor rotation reduction during anatomical reduction.

In Different Gender Groups, What Is the Impact of the Fibular Notch on the Severity of High Ankle Sprain: A Retrospective Study of 360 Cases.

OBJECTIVES: The role of the distal tibiofibular ligament in the occurrence of high ankle sprain (HAS) has been widely studied. But previous studies have overlooked the physiological and anatomical differences between males and females and have not further refined gender. Therefore, the impact of the anatomical morphology of fibular notch (FN) on HAS in different genders is still unclear. This study aimed to explore the impact of different types of FN on the severity of HAS and to estimate the prognosis of patients with HAS while excluding anatomical differences caused by gender. METHODS: One hundred and eighty patients with HAS were included in this study as the experimental group (i.e., HAS group). They were further divided into four groups according to gender and FN depth, with deep concave FN ≥ 4 mm and shallow flat FN < 4 mm. Another 180 normal individuals were set as the control group. The FN morphological indicators, tibiofibular distance (TFD), and ankle mortise indexes were measured and compared with those in HAS group. The independent t-test was used to compare continuous variables between groups, the intraclass correlation coefficient (ICC) was used to analyze the reliability of intra-observer measurement, and the Pearson correlation coefficient was used to verify the correlation between FN and the severity of HAS. RESULTS: In males with shallow flat type, the measurements of anterior tibiofibular distance (aTFD), middle tibiofibular distance (mTFD), posterior tibiofibular distance (pTFD), front ankle mortise width (fAMW), middle ankle mortise width (mAMW), posterior ankle mortise width (pAMW), and depth of ankle mortise (DOAM) in HAS group were significantly larger than those in normal group (p < 0.05). In male patients with deep concave type, the measurements of aTFD, mTFD, fAMW, mAMW, and DOAM were significantly larger than those in normal group (p < 0.05). Among female patients with shallow flat type, the measurements of aTFD, mTFD, pTFD, fAMW, mAMW, pAMW, and DOAM were found to be significantly larger than those in normal group (p < 0.05). Among female patients with deep concave type, the measurements of mTFD, pTFD, fAMW, mAMW, and DOAM were found to be significantly larger than those of the normal group (p < 0.05). The depth of FN was negatively correlated with TFD, and the AOFAS score of patients with shallow flat type was significantly lower than that of patients with deep concave type after treatment (p < 0.05). CONCLUSIONS: In different gender groups, compared with the normal controls, the TFD and partial ankle mortise indices were significantly different in HAS patients. Moreover, FN depth was negatively correlated with TFD, and the AOFAS score of shallow flat patients was significantly lower than that of deep concave patients. These suggested that shallow flat FN may be associated with more severe distal tibiofibular ligament injury and ankle mortise widening, leading to poorer prognosis. This should be taken seriously in clinical practice.

Association between the distal tibiofibular syndesmosis morphology classification and ankle osteoarthritis: a retrospective study.

BACKGROUND: Syndesmosis injury is proposed to contribute to ankle stability and osteoarthritis (OA). However, whether distal tibiofibular syndesmosis structure is closely related to ankle OA is unclear. We hypothesized that different DTS morphology classifications would affect the biomechanics properties in ankle OA. The study aimed to determine the association between the distal tibiofibular syndesmosis (DTS) morphological classification and ankle OA. METHODS: This is a retrospective study examining imaging data of 147 patients (87 males and 60 females) with ankle OA. Magnetic resonance imaging was used to access the DTS morphological classification, according to measuring various parameters. Joint space narrowing and osteophytes were measured using ankle weight-bearing radiography. The classification and parameters were analyzed to determine the relationship between the syndesmosis classification and the abnormality of ankle OA. RESULTS: Five morphological classifications of the DTS, including Chevron (19.6%), Widow's peak (16.2%), Flat (22.3%), Trapezoid (32.0%), and Crescent (19.6%), were shown. There were statistical differences between DTS classification and tibial angle surface angle (TAS) (P = .009) and talar tilt angle (TTA) (P = .014). The TAS (degree) of the Crescent (86.47 ± 3.21) was less than Chevron (88.75 ± 2.72) (P = .006), Widow's peak (89.26 ± 3.15) (P = .001), Flat (88.83 ± 3.62) (P = .003) and Trapezoid (88.11 ± 2.62) (P = .041), respectively. The TTA (degree) of Crescent (86.83 ± 5.30) was less than Chevron (89.28 ± 2.46) and Widow's peak (89.82 ± 3.41). The men were greater than women for TAS (P = .008) and angle (P = .003), which are consistent with osteophyte (P = .019) and the modified Kellgren-Lawrence grades (P = .041) between gender. CONCLUSIONS: DTS morphological classification might affect the biomechanics properties in TAS and TTA in ankle OA. In clinical practice, surgeons should pay attention to the effects of DTS on ankle OA. LEVEL OF EVIDENCE: Level III, retrospective study.

[TightRope elastic fixation combined with functional total repair of inferior tibiofibular ligament in treatment of distal tibiofibular syndesmosis injury].

Objective: To study the effectiveness of TightRope elastic fixation combined with functional total repair of the inferior tibiofibular ligament in the treatment of distal tibiofibular syndesmosis injury. Methods: The clinical data of 34 patients with distal tibiofibular syndesmosis injury who met the selection criteria between January 2020 and January 2022 were retrospectively analyzed, and they were divided into improved group (TightRope elastic fixation combined with functional total repair of inferior tibiofibular ligament) and control group (distal tibiofibular screw fixation) according to the surgical methods, with 17 cases in each group. There was no significant difference in age, gender, body mass index, fracture type, and other baseline data between the two groups (P>0.05). The operation time, intraoperative blood loss, and complications were recorded in the two groups. The American Orthopaedic Foot and Ankle Society (AOFAS) score, ankle metatarsal flexion and dorsal extension range of motion were used to evaluate the ankle function. The patient satisfaction survey was conducted at last follow-up. Results: All 34 patients were followed up 8-20 months, with a median of 13 months. The operation time and intraoperative blood loss in the improved group were significantly longer than that in the control group (P<0.05). In the improved group, no infection or poor reduction occurred, and only 1 patient had TightRope knot reaction at 6 months after operation. In the control group, there were 2 cases of poor reduction, 1 case of lower tibiofibular screw rupture, and 1 case of subcutaneous infection (cured after anti-infection treatment). There was no significant difference in the incidence of complications between the two groups (P>0.05). At last follow-up, the AOFAS score and ankle metatarsal flexion and dorsal extension range of motion of the improved group were significantly better than those of the control group (P<0.05). The satisfaction rates of patients in the improved group and the control group were 94.1% and 82.4%, respectively, showing significant difference (P<0.05). Conclusion: TightRope elastic fixation combined with functional total repair of inferior tibiofibular ligament in the treatment of distal tibiofibular syndesmosis injury has sufficient fixation strength, and can achieve better effectiveness and joint function compared with traditional screw fixation.

Does the Level of Syndesmotic Screw Insertion Affect Clinical Outcome after Ankle Fractures with Syndesmotic Instability?

OBJECTIVE: Ankle fractures are often combined with syndesmotic instability, requiring reduction and stabilization. However, the optimal level for syndesmotic screw positioning remains unclear. This study aims to evaluate the effect of different syndesmotic screw insertion levels on postoperative clinical outcomes and determine whether an optimal level exists. METHODS: This retrospective study included data from 43 adult patients with acute closed ankle fractures combined with intraoperative evidence of unstable syndesmotic injuries who underwent open reduction internal fixation from January 1, 2017 to March 1, 2018 according to the inclusion and exclusion criteria. All 43 patients were divided into three groups based on the syndesmotic screw placement level: trans-syndesmotic group: screw level of 2-3 cm; inferior-syndesmotic group: screw level <2 cm; and supra-syndesmotic group: screw level >3 cm. Clinical outcomes were measured at the final follow-up, including the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, Olerud-Molander Ankle Score (OMAS), short-form 36-item questionnaire (SF-36), visual analogue scale (VAS) score and restrictions in ankle range of motion (ROM). The relationships between screw placement level and clinical outcomes were analyzed with the Kruskal-Wallis H-test and Spearman correlation analysis. RESULTS: The median follow-up duration was 15 months (range, 10-22 months). No patients developed fracture nonunion or malunion or experienced hardware failure. The outcome scoring systems showed an overall score for the entire group of 94.91 points for the AOFAS ankle-hindfoot score, 83.14 for the OMAS, 96.65 for the SF-36, 1.77 for the VAS, 9.14° for the restrictions in dorsiflexion, and 1.30° for the restrictions in plantarflexion. There were no significant differences among three groups in clinical outcomes (P > 0.05). Neither the AOFAS score nor OMAS had significant correlations with screw insertion level (P = 0.825 and P = 0.585, respectively). No postoperative arthritis or widening of the tibiofibular space was observed at the final follow-up. CONCLUSION: Different syndesmotic screw placement levels appear not to affect the clinical outcomes of ankle fractures with syndesmotic instability. No optimal level was observed in this study. Our findings suggest other clinically acceptable options apart from syndesmotic screw placement 2-3 cm above the ankle.

Current research on injury to the distal tibiofibular syndesmosis and prospects of its treatment / 中华创伤骨科杂志

Among ankle injuries, the injury to the distal tibiofibular syndesmosis is common and likely neglected. The stability of the distal tibiofibular syndesmosis is related to the depth of the fibular notch. In imaging diagnosis, X-ray examination cannot be used for a definite diagnosis of the injury to the distal tibiofibular syndesmosis. For diagnosis of the distal tibiofibular separation>3 mm, CT scan can be accurate but is not sensitive enough for a separation<1 mm while MRI is more sensitive in diagnosis of the injury. Arthroscopy has gradually been used as the "gold standard" in diagnosis of the injury to the distal tibiofibular syndesmosis due to its advantage of direct vision. The distal tibiofibular separation occurs in the injuries of pronation external rotation Ⅳ°, supination external rotation Ⅲ° and Ⅳ°, and pronation abduction Ⅱ° and Ⅲ° by the Lange-Hansen classification. Most patients with simple stable injury to the distal tibiofibular syndesmosis may have a good prognosis after nonoperative treatment. Surgical anatomic reduction and maintenance of stability of the distal tibiofibular syndesmosis are the basic management principles for unstable distal tibiofibular syndesmosis or the injury to the distal tibiofibular syndesmosis combined with ankle fracture. Screw fixation is the most commonly used in the surgical treatment of the injury. Elastic fixation has the advantages of maintaining the biological characteristics of the distal tibiofibular syndesmosis fretting joint, better reduction fault tolerance, and lower rates of complications and long-term reduction loss. The angle of nail placement is the key to maintaining good reduction of the distal tibiofibular syndesmosis, but there has been little description of the specific methods to ensure the theoretical angle of nail placement in practice. This article also reviews the prospects of the future treatment of the injury to the distal tibiofibular syndesmosis.

TightRope elastic fixation combined with functional total repair of inferior tibiofibular ligament in treatment of distal tibiofibular syndesmosis injury / 中国修复重建外科杂志

OBJECTIVE@#To study the effectiveness of TightRope elastic fixation combined with functional total repair of the inferior tibiofibular ligament in the treatment of distal tibiofibular syndesmosis injury.@*METHODS@#The clinical data of 34 patients with distal tibiofibular syndesmosis injury who met the selection criteria between January 2020 and January 2022 were retrospectively analyzed, and they were divided into improved group (TightRope elastic fixation combined with functional total repair of inferior tibiofibular ligament) and control group (distal tibiofibular screw fixation) according to the surgical methods, with 17 cases in each group. There was no significant difference in age, gender, body mass index, fracture type, and other baseline data between the two groups (P>0.05). The operation time, intraoperative blood loss, and complications were recorded in the two groups. The American Orthopaedic Foot and Ankle Society (AOFAS) score, ankle metatarsal flexion and dorsal extension range of motion were used to evaluate the ankle function. The patient satisfaction survey was conducted at last follow-up.@*RESULTS@#All 34 patients were followed up 8-20 months, with a median of 13 months. The operation time and intraoperative blood loss in the improved group were significantly longer than that in the control group (P<0.05). In the improved group, no infection or poor reduction occurred, and only 1 patient had TightRope knot reaction at 6 months after operation. In the control group, there were 2 cases of poor reduction, 1 case of lower tibiofibular screw rupture, and 1 case of subcutaneous infection (cured after anti-infection treatment). There was no significant difference in the incidence of complications between the two groups (P>0.05). At last follow-up, the AOFAS score and ankle metatarsal flexion and dorsal extension range of motion of the improved group were significantly better than those of the control group (P<0.05). The satisfaction rates of patients in the improved group and the control group were 94.1% and 82.4%, respectively, showing significant difference (P<0.05).@*CONCLUSION@#TightRope elastic fixation combined with functional total repair of inferior tibiofibular ligament in the treatment of distal tibiofibular syndesmosis injury has sufficient fixation strength, and can achieve better effectiveness and joint function compared with traditional screw fixation.

[Comparison of short-term effectiveness of metal screws and absorbable screws in repair of distal tibiofibular syndesmosis].

Objective: To compare the short-term effectiveness of repairing distal tibiofibular syndesmosis with metal screws and absorbable screws. Methods: A retrospective analysis was performed on the clinical data of 63 patients with ankle fracture combined with injury of the distal tibiofibular syndesmosis admitted between January 2017 and January 2020. Among them, 31 patients were treated with absorbable screw fixation of the distal tibiofibular syndesmosis (research group) and 32 patients were treated with metal screw fixation of the distal tibiofibular syndesmosis (control group). There was no significant difference in gender, age, cause of injury, surgical side, time from injury to operation, fracture type, preoperative visual analogue scale (VAS) score, and American Orthopaedic Foot & Ankle Society (AOFAS) score between the two groups ( P>0.05). The operation time and fracture healing time were recorded and compared between the two groups. X-ray film was taken to evaluate the effect of ankle joint reduction and fixation. Olerud-Molander ankle fracture efficacy score (short for OM score), AOFAS score, and VAS score were used to evaluate the effectiveness. Results: There was no significant difference in operation time between the two groups ( t=-0.683, P=0.497). In the control group, 1 case of delayed healing and 1 case of poor healing occurred in the lateral incision after operation, which healed after dressing change; the rest of the patients had primary healing of the incision. Patients in both groups were followed up 12-24 months, with an average of 13.8 months. In the control group, 1 patient with fracture of pronation and external rotation walked with full weight bearing after removing the metal screw of the distal tibiofibular syndesmosis at 8 weeks after operation, the anatomical plate of the lateral malleolus was broken, and the lateral malleolus was fixed again and recovered after 5 months; 1 patient had mild ankle pain after operation, and the pain disappeared after removing the metal screw of the distal tibiofibular syndesmosis at 8 weeks. No complication such as nerve and blood vessel injury occurred in all patients. There was no significant difference in fracture healing time between the two groups ( t=-1.128, P=0.264). The AOFAS and VAS scores significantly improved in both groups at 12 months after operation ( P<0.05). There was no significant difference between the two groups in the OM scores, and the difference of AOFAS and VAS scores between before and after operation ( P>0.05). Conclusion: Using absorbable screws to repair the distal tibiofibular syndesmosis can effectively restore the ankle acupoint structure, prevent ankle instability, and restore good ankle function. There is no significant difference in effectiveness between absorbable screws and metal screws, and there is no need for secondary operation to remove screws.

Application of an arched, Ni-Ti shape-memory connector in repairing distal tibiofibular syndesmosis ligament injury.

OBJECTIVE: To investigate the clinical effect of internal fixation of a Ni-Ti arched shape-memory connector in the treatment of distal tibiofibular syndesmosis ligament injury. METHODS: From January 2013 to January 2016, 108 cases of ankle fracture with distal tibiofibular syndesmosis ligament injury in our hospital were selected, and all of them were fixed with ASCs or screw fixation. The functional evaluation and efficacy evaluation were performed according to the Olerud Molander Ankle Score (Omas) and SF-36. At the same time, follow-ups recorded the incidence of postoperative complications: osteoarthritis, superficial infection, symptomatic hard and soft tissue irritation, early removal and poor reduction of internal fixation, and later loss of reduction. RESULTS: In the ASC(Ni-Ti Arched shape-memory Connector) group, the incidence of symptomatic hardware, soft tissue or superficial infection decreased to 2.77%(from 13.8% or 11.1% in SCREW group). The early removal rate(2.77%) of internal fixation was also lower than that of the screw group. While the incidence of osteoarthritis is 13.8% in SCREW group, the incidence of osteoarthritis in the later follow-up was also as low as 1.38% in ASC group. Loss of fracture reduction due to removal of the fixation device for the distal tibiofibular syndesmosis ligament was not observed in the ASC group. With two postoperative scoring systems (OMAS and SF-36), patients in the ASC group significantly get higher score than that in SCREW group. CONCLUSION: The design of the Ni-Ti arched shape-memory connector can be adapted to the irregular anatomical structure of the malleolus and the ability to continue to contract by body temperature. The use of ASCs in fixation of articular ligaments can preserve a slight range of motion, and the results suggest that ASCs can effectively reduce the incidence of fixation looseness, fracture, infection and other complications.

Statistical shape model-based tibiofibular assessment of syndesmotic ankle lesions using weight-bearing CT.

Forced external rotation is hypothesized as the key mechanism of syndesmotic ankle injuries, inducing a three-dimensional deviation from the normal distal tibiofibular joint (DTFJ) alignment. However, current diagnostic imaging modalities are impeded by a two-dimensional assessment, without considering ligamentous stabilizers. Therefore, our aim is threefold: (1) to construct an articulated statistical shape model of the normal DTFJ with the inclusion of ligamentous morphometry, (2) to investigate the effect of weight-bearing on the DTFJ alignment, and (3) to detect differences in predicted syndesmotic ligament length of patients with syndesmotic lesions with respect to normative data. Training data comprised non-weight-bearing CT scans from asymptomatic controls (N = 76), weight-bearing CT scans from patients with syndesmotic ankle injury (N = 13), and their weight-bearing healthy contralateral side (N = 13). Path and length of the syndesmotic ligaments were predicted using a discrete element model, wrapped around bony contours. Statistical shape model evaluation was based on accuracy, generalization, and compactness. The predicted ligament length in patients with syndesmotic lesions was compared with healthy controls. With respect to the first aim, our presented skeletal shape model described the training data with an accuracy of 0.23 ± 0.028 mm. Mean prediction accuracy of ligament insertions was 0.53 ± 0.12 mm. In accordance with the second aim, our results showed an increased tibiofibular diastasis in healthy ankles after weight-bearing. Concerning our third aim, a statistically significant difference in anterior syndesmotic ligament length was found between ankles with syndesmotic lesions and healthy controls (p = 0.017). There was a significant correlation between the presence of syndesmotic injury and the positional alignment between the distal tibia and fibula (r = 0.873, p < 0,001). Clinical Significance: Statistical shape modeling combined with patient-specific ligament wrapping techniques can facilitate the diagnostic workup of syndesmosic ankle lesions under weight-bearing conditions. In doing so, an increased anterior tibiofibular distance was detected, corresponding to an "anterior open-book injury" of the ankle syndesmosis as a result of anterior inferior tibiofibular ligament elongation/rupture.

Distal tibiofibular syndesmosis: A meta-analysis of cadaveric studies.

Though injuries to the distal tibiofibular (DTF) syndesmosis are commonly encountered in orthopedic and trauma settings, its anatomical structures have been poorly researched. The commonly overlooked DTF ligament injuries are known to cause chronic ankle pain, instability and post-traumatic osteoarthritis. Quantitative and morphological evidence synthesis has not been yet conducted. A meta-analysis was conducted to collect data from morphological studies to document more accurate details on the prevalence, size, and insertion sites of its components. The Checklist for Anatomical Reviews and Meta-Analyses (CARMA) was followed. Ten studies met the inclusion criteria with a total of 265 investigated ankles. The analysis demonstrated that the anterior and posterior tibiofibular ligaments along with the interosseous ligament were present in 100% of joints. The inferior transverse tibiofibular and the distal fascicle of the anterior tibiofibular ligament were the least prevalent with frequencies of 96% and 86.5%, respectively. The inferior transverse ligament was recorded as the longest ligament. The widest ligament was found to be the interosseous tibiofibular ligament at its fibular attachment. The thickest of the ligamentous components was the posterior tibiofibular ligament. While more cadaveric research is warranted, these results would help directing future biomechanical investigations and planning new research to further aid in diagnostic and therapeutic approaches to the injuries of the distal tibiofibular syndesmosis.

Mechanics Analysis on Novel Micro-Movement Elastic Implant of Distal Tibiofibular Syndesmosis in Dorsiflexion Position / 医用生物力学

Objective To study mechanical properties of the novel micro-movement elastic implant of distal tibiofibular syndesmosis in dorsiflexion position.Methods A combination of simulation and experiment was used. The normal ankle dorsiflexion model, the bone nail repaired model and the micro-movement elastic implant repaired model were established by using Mimics and CT data. Besides, ANSYS Workbench was used for finite element analysis. Mechanical experiments on lower limb specimens were conducted on Instron E10000 mechanical test instrument, and five sets of experimental data were measured and analyzed.Results Mechanical properties of the micro-movement elastic implant repaired model were closer to those of the normal ankle dorsiflexion model, but stress of the micro-movement elastic implant repaired mode was greater than that of the bone nail repaired model. The results of two-sample heteroscedasticity t test indicated that there was no significant difference in resistance torque between the micro-movement elastic implant repaired model and the normal ankle dorsiflexion model.Conclusions For dorsiflexion position, repairing mechanical properties of the novel micro-movement elastic implant are much better than those of the bone nail, and there is still room for optimizing the micro-movement elastic implant.

Biomechanical comparison of screw, tightrope and novel double endobutton in the treatment of tibiofibular syndesmotic injuries.

BACKGROUND: Adequate reduction and stabilization of the syndesmosis are significant to prevent early degeneration of the ankle joint and get better clinical outcomes. However, the routine surgical methods have diffierent limitations. The purpose of this study was to develop a novel double Endobutton fixation to treat the distal tibiofibular syndesmotic injuries, and determine whether the novel double Endobutton fixation demonstrates a better biomechanical property compare with the intact syndesmosis, the screw fixation and the Tightrope fixation. METHODS: Twenty-four normal fresh-frozen ankle specimens with a mean age of 42 ± 8 (range, 28-62) years were randomly divided equally into four groups: (1) the intact group, (2) the screw group, (3) the Tightrope group, (4) the Endobutton group. 3D printer technology was used to establish the personalized distal tibiofibular syndesmotic navigation modules to determine the accurate bone tunnel. Axial loading was applied in five ankle positions: neutral position, dorsiflexion, plantar flexion, varus and valgus. Rotation torque was applied in two ankle rotation of the neutral position: internal and external. RESULTS: In most situations, the displacements of the intact group were larger than the screw group, the Tightrope group and the Endobutton group (P < .05), and the displacements of the screw group were smaller than other three groups (P < .05). The displacements of the double Endobutton group were slightly larger than the Tightrope group but no significant differences were found between these two groups except in the dorsiflexion position of axial loading experiments (P < .05). The novel double Endobutton fixation was steadier than intact syndesmosis and more micromotional than screw fixation. CONCLUSION: Our study demonstrated that the novel double Endobutton can be considered as the better fixation in treatment of distal tibiofibular syndesmotic injuries. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Self-made wire-rope button plate: A novel option for the treatment of distal tibiofibular syndesmosis separation.

OBJECTIVE: To compare the clinical effect of the self-made wire-rope button plate and cortical screw in the treatment of the distal tibiofibular syndesmosis separation. METHODS: Total 26 patients with distal tibiofibular syndesmosis separation were treated with internal fixation with a self-made wire-rope button plate and cortical screw. They were divided into a self-made wire-rope button plate group and cortical screw group. self-made wire-rope button plate group: 12 cases of inferior tibiofibular syndesmosis were reconstructed by self-made wire-rope button plate. Cortical screw group: 14 cases of inferior tibiofibular syndesmosis were reconstructed by cortical screw. The follow-up data of 2, 6, 12 weeks and 6 and 12 months after operation were collected. RESULTS: There was no significant difference in operative time, the amount of intraoperative bleeding and postoperative complications between the two groups (P > 0.05). Comparison of postoperative complications: There was no loosening and rupturing of internal fixation in the self-made wire-rope button plate group. In the cortical screw group, the rupture of screws was found in 1 case, which occurred in the 10th weeks after the operation, and the broken screws were removed after 1 year with other internal fixations. Within 12 weeks of reoperation to remove the internal fixation rate: There was a significant difference in the rate of reoperation to remove the internal fixation within 12 weeks (p < 0.05). At the last follow-up, the AOFAS score of the ankle joint were 94 ± 4.79 in the self-made wire-rope button plate group and 92.8 ± 6.73 in the cortical screw group. There was no significant difference (P > 0. 05). CONCLUSION: The self-made wire-rope button plate and cortical screw can effectively treat the separation of the tibiofibular syndesmosis. It provides a new choice for the treatment of inferior tibiofibular syndesmosis.

Can Syndesmosis Screws Displace the Distal Fibula?

Background. There has been historical debate as to whether the distal tibiofibular syndesmosis can be overtightened during operative fixation. We used finite-element analysis to determine if overtightening of syndesmotic screws can cause widening of the lateral gutter clear space in the ankle joint. Methods. A 3D finite-element model was constructed and analyzed using geometries from a computed tomography scan of a cadaveric lower leg. Starting 2 cm from the plafond, screw fixation was simulated at 5-mm increments to a distance of 5 cm from the plafond. The fibula was compressed 2 mm toward the tibia at each interval, and the change in distance between the lateral talus and distal fibula was measured. Results. Medial deflection of the fibula resulted in widening of the lateral clear space, which was proportional to the amount of deflection. The effect increased as screws were placed closer to the plafond, with 1.5 mm of widening at 2 cm (0.76 mm/mm) versus 0.7 mm at 5 cm (0.34 mm/mm). Conclusion. Our finite-element model demonstrated that overtightening of the distal tibiofibular syndesmosis with medial fibular displacement can cause widening of the lateral clear space. Clinical relevance. The results suggest that screws placed farther from the plafond widen the lateral clear space to a lesser degree, which may be advantageous during surgical fixation to prevent clear space widening and increased tibiotalar contact forces.Levels of Evidence: Level I.