Inferior Tibiofibular Syndesmosis Research Articles

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

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. A female patient in her early twenties sprained her left ankle while running, suffering regional pain, swelling, and limited mobility. We diagnosed a Maisonneuve fracture with superior fibular fracture and Volkmann tuberosity fracture, a slight separation of inferior tibiofibular syndesmosis (ITS). 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. 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. 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.

Open Reduction and Internal Fixation for Supination-External Rotation Type IV Ankle Fractures by Means of Anterolateral and Posterolateral Approaches.

The present study aimed to analyze and compare the efficacy of the anterolateral and posterolateral approaches for surgical treatment of supination-external rotation type IV ankle fractures. This retrospective study enrolled 60 patients (60 feet) with supination-external rotation type IV ankle fractures, including 30 patients (30 feet) treated by means of the anterolateral approach and 30 patients (30 feet) treated by means of the posterolateral approach. Postoperative clinical efficacy was compared between the groups based on operation time, intraoperative blood loss, postoperative complications, fracture healing time, visual analog scale scores, Short Form-36 Health Survey scores, and American Orthopedic Foot and Ankle Society scores. Comparisons between the two groups were performed using independent-samples t tests and analyses of variance. Intragroup differences were compared using paired t tests, and the χ2 test was used to compare categorical variables. All 60 included patients completed follow-up ranging from 12 to 18 months (mean duration, 14.8 ± 3.5 months). Although baseline characteristics were similar in the two groups, there were significant differences in operation time (86.73 ± 17.44 min versus 111.23 ± 10.05 min; P < .001) and intraoperative blood loss (112.60 ± 25.05 mL versus 149.47 ± 44.30 mL; P < .001). Although fracture healing time (10.90 ± 0.66 weeks versus 11.27 ± 0.94 weeks; P = .087) was shorter in the anterolateral group than in the posterolateral group, the difference was not significant. Postoperative complications occurred in one and three patients in the anterolateral and posterolateral approach groups, respectively. Visual analog scale scores were significantly lower in the anterolateral group than in the posterolateral group (1.43 ± 0.50 versus 1.83 ± 0.75; P = .019), although there was no significant difference in Short Form-36 Health Survey scores between the groups (73.63 ± 4.07 versus 72.70 ± 4.04; P = .377). However, American Orthopedic Foot and Ankle Society scores were higher in the anterolateral group than in the posterolateral group (80.43 ± 4.32 versus 75.43 ± 11.32; P = .030). Both the anterolateral and posterolateral approaches can achieve good results in the treatment of supination-external rotation type IV ankle fractures. Compared with the posterolateral approach, the anterolateral approach is advantageous for the treatment of supination-external rotation type IV ankle fractures given its safety and ability to reduce trauma, clear field of view revealed, and allow for exploration and repair of the inferior tibiofibular anterior syndesmosis within the same incision.

Clinical outcomes of an olive wire and external fixator versus a metallic screw in the treatment of inferior tibiofibular syndesmosis injuries in ankle fractures

BackgroundMetal screws are the most widely used in treating syndesmotic injuries, but failure and the rigidity of the screws can threaten the success of the treatment and increase the cost of care. We have provided an alternative with an olive wire and external fixator(OWEF) used for syndesmotic fixation. MethodsA retrospective longitudinal follow-up study was conducted. From February 2011 to January 2018, 58 of 72 patients with ankle fractures and associated syndesmotic disruption were treated with either screw or OWEF fixation. The costs, complications, and clinical outcomes using Olerud-Molander score and Visual Analog score in screw and OWEF fixation group were compared. ResultsWe found the severity of the injury, BMI of the patients and the different fixation methods were determinants of the complications and clinical outcomes. But if no malreduction of the syndesmosis was present, no difference in clinical result was detected. ConclusionThe OWEF method appeared to be at least equally functional and effective to screw fixation while maintaining possible lower complication rate. Levels of clinical evidenceLevel 3

Investigation of the Characteristics and Mechanism of Interosseous Membrane Injuries in Typical Maisonneuve Fracture

Previous studies on the mechanism and scope of interosseous membrane injury in Maisonneuve fractures have been inconsistent. In order to better guide clinical treatment, the characteristics and mechanism of interosseous membrane injuries and proximal 1/3 fibular fracture in typical Maisonneuve fracture were investigated. The study comprised 15 patients between January 2019 and June 2021 with Maisonneuve fracture. All patients received X-ray and MRI examination of the calf and ankle joint, and CT scanning of the ankle joint. The injuries of medial structure, inferior tibiofibular syndesmosis, fibula, posterior malleolus, and interosseous membrane were evaluated. MR images of the calf showed that the injury of interosseous membrane (IOM) was from the syndesmosis to the proximal fibular fracture site in two patients, with a range of 32.3 and 29.8 cm, respectively. In the other 13 patients, the IOM rupture was not only confined to the distal third of the calf, but also close to the fibula fracture, and the IOM was intact between the two fracture sites. The range of distal IOM rupture was 3.7-12.2cm, with an average of 8.06 ± 2.35 cm. The proximal IOM was completely ruptured from the fibular side at the site of the fibular fracture and the range was 4.1-9.1 (average: 6.75 ± 1.64) cm. The average length of the integrate middle segment of the IOM was 14.55 ± 4.11 (5.6-20.3) cm. MR images of the calf also showed partial rupture of the posterior tibial muscle at the ending point on the fibula in 15 cases, partial rupture of soleus muscle and flexor hallucis longus in seven cases. The rupture of the IOM was caused by a combination of abduction and external rotation violence. It was manifested in two forms, most of which was not only distal end but also near fibular fracture site ruptures with the middle part intact, and a few were ruptures of the IOM from the ankle to the near fibular fracture site. The tibialis posterior muscle may be related to the location of the fibular fracture.

Kirschner wire combined with PEEK anchor for the treatment of WagstaffeⅡfracture

To explore clinical effect of Kirschner wire combined with PEEK anchor with thread to fix fibula bone block in WagstaffeⅡfracture. From January 2018 to December 2020, 29 patients with WagstaffeⅡfracture of ankle joint were treated with Kirschner wire fixation of avulsed fibular bone block, PEEK with thread anchor repair and reinforcement, and plaster external fixation, including 18 males and 11 females, aged from 27 to 69 years old with an average of (46.3±10.2) years old. All of them were unilateral operations, and the time from injury to operation ranged from 3 to 5 days with an average of(4.05±0.63) days. Clinical efficacy was evaluated by using American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot functional scoring system and visual analogue scaleat scoring system before and after operation at 6 months. All patients were followed up from 6 to 12 months with an average of (9.7±2.1) months. Two patients occurred pain of ankle joint during walking, which was relieved after strengthening rehabilitation exercise and anti-nflammatory and analgesic drug treatment. AOFAS score was incrased from(62.16±19.73) preoperativyly to(91.35±6.37) at 6 months after operation (t=5.51, P<0.01);15 patients got excellent results, 12 moderate and 2 good. VAS was decreased (5.91±1.57) preoperativly to (0.41±0.37) at 6 months after operation(t=10.54, P<0.01). Kirschner wire combined with PEEK anchor with thread to fix fibula bone block in WagstaffeⅡfracture strengthen repair of inferior tibiofibular syndesmosis ligament and anterior talofibular ligament, and effectively relieved ankle joint pain, obtain good function recovery, the avulsion fracture block was fixed securely, and receive good clinical effect.

Closed Reduction for the Treatment of Grade IV Supination-External Rotation Fracture of the Ankle Joint: A Retrospective Analysis.

ObjectiveTo investigate the curative effect of closed reduction and external fixation in the treatment of grade IV supination‐external rotation fractures of the ankle joint.MethodsFifty‐six patients treated with closed reduction and external fixation from February 2016 to March 2020 were included in this retrospective study, all with sprains. After receiving nerve block anesthesia, the patient underwent closed reduction under C‐arm fluoroscopy, and the ankle joint was fixed in a dorsiflexion‐inversion position with casting and splints after the end of the fracture met the reduction standard by fluoroscopy. One week and four weeks after the reduction treatment, oblique axial and coronal MR scans of the ankle joint were performed to determine the degree of injury and healing of the inferior tibiofibular syndesmosis; anteroposterior and lateral X‐rays of the ankle joint (including the ankle acupoints) were regularly reviewed to observe the fracture alignment and healing. Combined with the images and physical examination, the patients were instructed to undergo ankle weight‐bearing rehabilitation training when they met the clinical healing standard, and at the last follow‐up, the Mazur ankle evaluation and grading system were used for evaluation. After the reduction, the images were evaluated according to the Leeds standard. The image healing of fracture was evaluated by callus growth criteria.ResultsThe follow‐up period of patients ranged from 11 to 58 months, with an average of 26.8 months. The clinical healing time was (8.51 ± 2.12) weeks. The excellent and good rating after reduction was 82.1%, and the excellent and good rating during clinical fracture healing was 73.2%, according to the Leeds imaging evaluation. According to the Mazur ankle evaluation and grading system, the excellent and good rating was 75.0%. Pairwise comparison of callus images at 4, 6 and 12 weeks showed statistically significant differences (P < 0.05), suggesting callus growth at different time periods. A total of 56 patients had anterior inferior tibial fibular ligament (AITFL) injuries (grade II‐III), among which 11 patients had AITFL injuries combined with grade II injuries of the interosseous ligament (IOL) and 4 patients had AITFL injuries combined with grade III injuries of the IOL.ConclusionsMost of the patients with grade IV supination‐external rotation fracture of the ankle joint had good prognosis after closed reduction and plaster combined with splint fixation. For patients with IOL injury who had poor prognosis, open reduction and internal fixation therapy is appropriate.

Clinical value of ankle arthroscopy in type Danis-Weber B ankle fracture with the distal tibiofibular syndesmosis injury

Objective To investigate clinical value of ankle arthroscopy in diagnosis of type Danis-Weber B ankle fracture with the distal tibiofibular syndesmosis injury. Methods From August 2014 to January 2018, a total of 52 cases of type Danis-Weber B ankle fractures with an average age of 35.37±11.19 years, including 31 males and 21 females were treated. Each patient underwent preoperative assessment, according to the patient's clinical manifestations and imaging examination before operation. The Cotton test and the external rotation test were conducted in the C arm X-ray to evaluate whether there is the distal tibiofibular syndesmosis injury. All fractures were treated with open reduction and internal fixation. Repair was conducted with 3.5 mm wire anchor and nail for triangular ligament injury. The Cotton test and external rotation test were performed under ankle arthroscopy. The injury of the lower tibiofibular syndesmosis was observed and evaluated by cotton test and external rotation test in patients who were found to be associated with lower tibiofibular joint injury. After internal fixation of fracture and repair of tibiofibular syndesmosis injury with TightRope, the repair effects of tibiofibular syndesmosis injury was observed under direct vision of ankle arthroscopy. The VAS score, AOFAS score and Baird-Jackson score was used as an index to observe the pain and ankle function before and after operation for 12 months follow-up. Results Preoperative X-ray showed 19 cases of lower tibiofibular joint injury. Preoperative CT showed 28 cases of lower tibiofibular joint injury. Preoperative MRI showed 39 cases of lower tibiofibular joint injury. A total of 36 cases of joint injury of lower tibiofibular syndesmosis were confirmed under arthroscopy of ankle. After repair of tibiofibular syndesmosis injury with TightRope, complete reduction and stability of inferior tibiofibular syndesmosis were confirmed under ankle arthroscopy. At 12 months after operation, the VAS score decreased from 8.13±1.32 points preoperation to 0.75±0.73 points after operation. The AOFAS and Baird-Jackson scores increased from 26.59±3.35 points, 16.44±3.63 points preoperation to 94.36±3.03 points, 90.29±6.45 points after operation, respectively. There was significant difference before and after operation (P<0.05). The postoperative VAS score, AOFAS score and Baird-Jackson score of 16 patients without lower tibiofibular ligament injury were confirmed in the ankle arthroscopy group, namely 0.58±0.67 points, 95.27±4.67 points, 91.98±9.23 points. Conclusion Ankle arthroscopy can be used to observe the injury of tibiofibular syndesmosis under direct vision. The positive rate of diagnosis of inferior tibiofibular syndesmosis injury was 69.2% (36/52). It can provide reliable evidence for correct diagnosis and treatment of type Danis-Weber B ankle fracture with lower tibiofibular joint injury with significant meaning in selecting operative methods and in evaluating the effect of lower tibiofibular ligament repair. Key words: Arthroscopy; Ankle joint; Fractures, bone; Ligaments, articular

Prevalence of syndesmosis injuries associated with acute ligamentous injuries on magnetic resonance imaging

Objective: The aim of this study was to evaluate the prevalence of inferior tibiofibular syndesmosis injuries in patients with acute lateral ligament injuries found on complementary nuclear magnetic resonance imaging (MRI) performed in a diagnostic imaging clinic. Methods: The images and medical reports of 429 ankle MRI examinations were evaluated from March to December 2017. After applying the exclusion criteria, 346 examinations were eliminated. Thus, a total of 93 MRI scans compatible with acute ankle ligament injuries were examined for associated syndesmosis injury. Results: The presence of syndesmosis injury was observed in 8 patients (8.6%). In all individuals with syndesmosis injuries, the anterior fibulotalar ligament (AFTL) and the anterior inferior tibiofibular ligament (AITFL) were affected. The most common lesion in this type of injury was partial AFTL lesion (6 cases), followed by partial AITFL lesion (5 cases). Of the 93 MRI results evaluated, the lateral complex ligament most commonly affected was the AFTL, with 91 lesions, partial and total, which were present in 97.85% of the MRI examinations. Partial AFTL lesions were observed in 49 patients (52.68%), representing the most common lesion, and total AFTL lesions were observed in 42 patients (45.16%). Conclusion: No increase was found in the prevalence of syndesmosis injuries associated with acute ligamentous injuries evaluated by MRI. Level of Evidence III; Diagnostic Studies; Study of Non Consecutive Patients.

Preliminary finite element analysis of anterior inferior tibiofibular syndesmosis injuries treated with screw and tight-rope fixation

To establish finite element models of anterior inferior tibiofibular syndesmosis injuries (AITSI), screw fixation and Tight-rope(TR) fixation, and to compare its force and displacement, so as provide evidence for clinical diagnosis and treatment. A three-dimensional model of a healthy ankle complex was developed by computed tomography (CT) images, and anterior inferior tibiofibular syndesmosis injuries(AITSI) model also established, then a screw was inserted into AITSI model to obtain a screw fixation model, and a Tight-rope system was put into AITSI model to obtain a TR model. Simulated loads were applied under three conditions:neutral position with single-foot standing, internal and external rotation of the ankle. The focus was on the stress of distal tibia, distal fibula and talus articular surface, and displacement of distal tibia and fibula. AITSI increased the stress of distal tibia, distal fibula and talus articular surface, which also increased the displacement of distal tibia and fibula. when AITSI existing, either a screw or TR could restrict excessive displacement of distal tibia and fibula. However, screw fixation severely limited normal physiological activity of ankle, and increased the force of distal tibia, distal fibula and articular surface of talus. The forces were concentrated on the screw. In the screw fixation model, the maximum force of tibia and fibula was more than 1.3 times that of TR model, and the contact force of talus articular surface was about 1.8 times. In the screw fixation model, the displacement of tibial attachment point of anterior tibiofibular ligaments was approximately 0.6 times that of the normal model. While the data in the TR model is about 1.1 times, but TR has poor control of the displacement of fibula. Severe anterior inferior tibiofibular syndesmosis injuries could cause stress and displacement distribution of ankle joint to change ankle instability and should be treated with internal fixation. Both of the screw and TR could be effective for AITSI. Tight-rope has advantages over screw fixation in terms of skeletal force, activity of ankle joint, and internal fixation fracture, but Tight-rope has disadvantage in fibular rotation. Patients with Weber type C ankle fractures and obesity are more suitable for screw fixation.

Arthroscopic Grading of Injuries of the Inferior Tibiofibular Syndesmosis

The objective of this study was to describe the technical details of performing a newly developed arthroscopic grading of inferior tibiofibular syndesmosis injuries. Arthroscopy is emerging as the gold standard for evaluating painful, unstable ankles. The inferior tibiofibular syndesmosis contributes substantially to disorders of the ankle. However, no structured grading system exists that would help surgeons evaluate injuries of the syndesmosis. Seventy-eight patients with pain or instability symptoms in the ankle were arthroscopically evaluated for syndesmosis injury. The lesions were graded according to the prospectively developed protocol.More than 61% of the patients had syndesmosis disruptions of various grades affecting the anterior/posterior ligaments or both ligaments. Fourteen patients had anterior ligament disruptions whereas 4 patients had posterior lesions; another 7 patients had both ligaments asymmetrically injured. Eighteen of the 78 patients had symmetric grade 1 lesions, and 5 had grade 2 lesions.More than half of chronic ankle pain cases have syndesmotic lesions. Symmetrical lesions of the anterior and posterior ligaments predominate, followed by isolated anterior ligament disruptions. The proposed grading system for inferior tibiofibular syndesmosis disruptions serves as a guide to systematic documentation of injuries of the syndesmosis.

Computational biomechanical analysis of postoperative inferior tibiofibular syndesmosis: a modified modeling method

To analyze the biomechanical effect of syndesmotic screw through three and four cortices, a total of 12 finite element models simulating healthy ankles, tibiofibular syndesmosis injured ankles, and post-operative ankles by screw fixations through three or four cortices were built. A set of biomechanical data were obtained to find that screw fixation methods for inferior tibiofibular syndesmosis can help recover most of the biomechanical relations of the ankle especially the tricortical fixation, while the screw of quadricortical fixation bear more stress than the tricortical fixation. The modeling method for finite element models was also modified for saving more time and realizing personalized modeling for clinical application.

Comprehensive Sonographic Protocol for Assessment of Ankle Inversion Injuries

Ankle inversion injuries are very common and well suited to ultrasound evaluation of soft tissue and bony injury. The breadth of information which may be obtained by the ultrasound assessment is broad and has led us to question the need for a dedicated protocol. A review of ultrasound , plain x-ray and MRI findings in patients suffering ankle inversion stress was performed to establish the scope of potential injury. The standard commonly performed ultrasound examination is inadequate and expansion to a more comprehensive protocol results in higher yield from the ultrasound examination. “Ultrasound is an excellent modality for soft tissue and bony assessment in patients who have suffered ankle inversion stress injury. This paper outlines a comprehensive protocol for thorough investigation of these injuries. It goes beyond the standard investigation of lateral ligaments to include: •Anterior ankle joint •Subtalar joint •Anterior talofibular ligament •Calcaneofibular ligament •Anterior inferior tibio-fibular syndesmosis •Dorsal talo-navicular ligament •Peroneal tendons •Superior peroneal retinaculum •Base of 5th metatarsal •Calcaneo-cuboid ligament (Bifurcate) •Extensor digitorum brevis muscle and origin enthesis •Fibula extensor retinaculum avulsion injury •Tibio-talar deltoid ligament (POMI Lesion) •Flexor retinaculum / deltoid ligament conjoint attachment to medial malleolus. A variety of commonly encountered patterns of injury will be discussed involving injury to these easily examined structures.”

Correlation between plain radiographs and three-dimensional reconstruction on measurements of proportion of posteri- or malleolar fragments to tibial plafond

Objective To investigate the correlation between plain radiographs and three-dimensional reconstruction on measurements of proportion of posterior malleolar fractures to tibial plafond. Methods From June 2013 to Dec. 2014, data of 27 patients with posterior malleolar fractures involving the tibial plafond who had undergone surgical treatment were retrospectively analyzed. There were 10 males and 17 females. The mean patient age was 48.9 years (range, 15-70 years). There were 14 cases of trimalleolar fracture, 11 of bimalleolar fracture and 2 cases with only posterior malleolar fracture. According to the Lauge-Hansen classification system, there were 22 cases of supination-external rotation, 1 of pronation-external rotation, 2 of pronation-abduction and 2 of unclassified type. According to the AO/OTA classification system, there were 22 cases of B, 3 of C and 2 of unclassified type. According to the Haraguchi classification system, there were 15 cases of type I and 12 of type II. There were 2 cases with the deep deltoid ligament disrupted and 3 cases with the inferior tibiofibular syndesmosis injury. The width of the posterior plafond fragment (PPF) and the remaining plafond fragment (RPF) were measured on the lateral plain radiograph. After 3D reconstruction was established, the area of the PPF and the RPF was measured. The width ratio of the PPF and the total plafond fragment (TPF) and the area ratio of the PPF and the TPF were calculated. Results The width ratio of the PPF and the TPF was 31.10% (range, 11.86%-52.24%), the area ratio of the PPF and the TPF was 20.13% (range, 5.86%-35.22%) and the correlation coefficient (r) between the width ratio of the PPF and the TPF and the area ratio of the PPF and the TPF was no statistically significant (r=0.350, P= 0.073). Concusion The width ratio of the PPF and the TPF could not represent the area ratio of the PPF and the TPF in the patients with the posterior malleolar fracture who's fracture line involved the plafond, and the ratio could be overrated in the lateral X-rays measurements. According to the plain radiographs, the evaluation of the proportion of posterior malleolar fragments to tibial plafond could not be as a reliable criterion for internal fixation of the posterior malleolar fragments. Key words: Ankle joint; Fractures bone; Imaging, three-dimensional

"Logsplitter" injury in clinical treatment and prognosis evaluation in ankle fractures

Objective Logsplitter injury as a kind of unique ankle fracture with the inferior tibiofibular syndesmosis separation caused by varieties of violence does not catch the attention of domestic orthopedic surgeons enough in the past years. This passage is to discuss the damage mechanism, clinical treatment and prognosis evaluation of this kind of injury through the analysis of the case of injury. Methods Retrospective analysis 23 patients of Logsplitter injury from December 2006 to December 2014, male in 17 cases, female in 6 cases, average age (43.68±12.67) years (21-60 years). Hurt injury in 9 cases, sports injury in 1 case, falling injury in 2 cases, traffic injuries in 10 cases, crushing injury in 1 case. Open injures in 10 cases, of which the Gustilo Ⅱtype in 7 cases, Gustilo ⅢA type or above in 3 cases, closed injuries in 13 cases. According to the AO/OTA fracture classification, 44c type in 19 cases, 44b type in 3 cases, 44a type in 1 case. Fibula fractures in 22 cases, 19 cases of medial malleolus fracture. Results 23 patients received follow-up, with an average period was (0.91±0.26) years (0.4-2.37 years). 21 cases underwent open reduction internal fixation (ORIF), 2 cases underwent closed reduction external fixation and K-wire fixation.17 cases were fixed with the syndesmosis screws, among them,1 screw was used to fix 14 cases, two screws were used to fix 3 cases;the utilization rate of 3.5 mm screws is higher, at 94.1%, and all screws were entered through 3 layers of cortical; Combined with medial malleolus fracture cases were fixed with cannulated screws/K-wire internal fixation. Average healing time of the skin surrounding the ankle skin was (2.26±1.91) weeks; average healing time of fracture was (15.34±5.13) weeks; Joint pain ocurred combined with joint space narrowing after loading in 18 cases, at 78.3%; Postoperative infection, 2 cases, the proportion was 8.7%; Fracture delayed union 1 case. Functional examination of the ankle joint (angle measurement method): Dorsiflexion average angle (23.9±2.21) degrees, Plantar flexion average angle (32.1±4.13) degrees. Average angle of introversion was (23.91±2.24) degrees. Hallux valgus average angle (27.6±3.81) degrees. 75 points and over were got in AOFAS in 21 cases, the ratio of excellent was 91.3%. Conclusion Logsplitter injury represents a kind of important and unique ankle fracture, dislocation and the inferior tibiofibular syndesmosis separation caused by varieties of violence, accompany with potentially soft tissue injury and platford injury, according to existing treatment principle and treatment strategy summarizied by us,the clinical therapeutic effect of this damage is ideal, functional recovery is relatively satisfactory prognosis. Key words: Ankle injuries; Fractures, bone; Fracture fixation, internal

Effects of inferior tibiofibular syndesmosis injury and screw stabilization on motion of the ankle: a finite element study.

Traditional studies of syndesmosis injury and screw stabilization have been conducted in cadaveric models, which cannot yield sufficient and exact biomechanical data about the interior of the ankle. The purpose of this study was to evaluate the effects of inferior tibiofibular syndesmosis injury (ITSI) and screw stabilization on the motion of the ankle with finite element analysis. Three-dimensional models of the ankle complex were created with CT images of a volunteer's right ankle in three states: normal, post-ITSI, and stabilization with a screw 2.5cm above (parallel to) the ankle. Simulated loads were applied under three conditions: neutral position with single foot standing, internal rotation, and external rotation of the ankle. Compared with the normal state, ITSI increased the relative displacement between the lower extremes of the tibia and fibula in the anteroposterior and mediolateral directions and the angular motion of the tibia, fibula, and talus at internal and external rotations (ERs). However, when stabilized with syndesmotic screws, the range of motion (ROM) and all these parameters significantly decreased. ITSI can lead to internal and ER instability of the ankle joint. Screw stabilization is effective in controlling the instability, but may reduce markedly the ROM of the ankle joint. Through this study, it can be proposed that the screws should be removed once the healing is gained in order to restore normal function of the ankle joint as soon as possible.

Analysis of the Stress and Displacement Distribution of Inferior Tibiofibular Syndesmosis Injuries Repaired with Screw Fixation: A Finite Element Study

BackgroundStudies of syndesmosis injuries have concentrated on cadaver models. However, they are unable to obtain exact data regarding the stress and displacement distribution of various tissues, and it is difficult to compare models. We investigated the biomechanical effects of inferior tibiofibular syndesmosis injuries (ITSIs) and screw fixation on the ankle using the finite element (FE) method.Methodology/Principal FindingsA three-dimensional model of a healthy ankle complex was developed using computed tomography (CT) images. We established models of an ITSI and of screw fixation at the plane 2.5 cm above and parallel to the tibiotalar joint surface of the injured syndesmosis. Simulated loads were applied under three conditions: neutral position with single-foot standing and internal and external rotation of the ankle. ITSI reduced contact forces between the talus and fibula, helped periarticular ankle ligaments withstand more load-resisting movement, and increased the magnitude of displacement at the lower extreme of the tibia and fibula. ITSI fixation with a syndesmotic screw reduced contact forces in all joints, decreased the magnitude of displacement at the lower extreme of the tibia and fibula, and increased crural interosseous membrane stress.Conclusions/significanceSevere syndesmosis injuries cause stress and displacement distribution of the ankle to change multidirectional ankle instability and should be treated by internal fixation. Though the transverse syndesmotic screw effectively stabilizes syndesmotic diastasis, it also changes stress distribution around the ankle and decreases the joint's range of motion (ROM). Therefore, fixation should not be performed for a long period of time because it is not physiologically suitable for the ankle joint.

Effects of the screw positions at the tibiofibular syndesmosis on the stress distribution at the ankle: a finite element analysis

Objective To analyze the effects of 2 different screw positions on the stress distribution at the ankle in three-dimensional finite element models of screw fixation of the inferior tibiofibular syndesmosis.Methods Helical CT scan images of the right foot of a 30 year-old male volunteer were obtained.Software (Mimics,SolidWorks and Simulation) was used to reconstruct three-dimensional bone structures,to simulate ligamentous connections and to generate articular contacts in 3 finite element models of normal ankle,screw fixation for tibiofibular syndesmosis injury with screw placement at 2.5 cm and 5.0 cm above the tibiotalar joint respectively.Loads were applied in simulations of the ankle at the neutral position with single-foot standing,internal rotation and external rotation for calculation of the stress distributions at the ankle.Results Screw fixation with 2 different placement positions decreased the stresses on the periarticular ligaments of the ankle but increased the stresses on the crural interosseous membrane.The stresses on the fibular attachment point of the proximal crural interosseous membrane increased to 28.91MPa and 27.76MPa respectively in the load simulation under internal rotation of the ankle.The contact forces at the major articulations were reduced.The contact forces in the load simulation under internal rotation of the ankle decreased to 136.55N and 120.14N between the tibia and talus,and 42.68N and 39.33N between the fibula and talus; the contact forces in the load simulation under external rotation of the ankle decreased to 167.93 N and 158.17 N between the tibia and talus,and 39.47N and 40.21N between the fibula and talus,respectively.Conclusion The three-dimensional finite element models of screw fixation of the inferior tibiofibular syndesmosis show that 2different screw placement positions will lead to changes in the stress distribution at the ankle but the differences are not significant between the 2 positions. Key words: Internal fixation; Biomechanics; Finite element analysis; Inferior tibiofibular syndesmosis injury

Screw versus staple in stabilization of diastasis of tibiofibular syndesmosis

The aim of this study is to compare the syndesmotic screw versus the staple in stabilization of the syndesmotic diastasis in unstable ankle fractures. Seventy-six patients with unstable ankle fractures (grades 3 or 4 Lauge-Hansen) and diastasis of the inferior tibiofibular syndesmosis underwent surgical treatment aiming for anatomical reduction and stable fixation. The syndesmotic diastasis was stabilized by one of two methods; in the first group (38 patients) it was stabilized with a screw; in the second group the syndesmosis was stabilized with a steel staple. The mean follow up period was 34.8 months and the mean age was 35.1 years. No recurrence of diastasis was detected in either group, chronic pain in the region of the syndesmosis was elicited in 65% of the first group compared with 5% in the second. Heterotrophic ossification was found in the region of the syndesmosis in 50% of the first group and in 5% of the second. Tibiofibular synostosis occurred at the site of the screw in one case in the first group. A broken screw complicated the first group in one case and a broken staple in the second group. The staple does not interfere with the kinematics of the ankle, it allows early mobilization and weight bearing and minimizes the possibility of heterotrophic ossification which causes chronic pain in the region of the syndesmosis. It is therefore considered as the superior alternative in stabilization of the syndesmotic diastasis.

The Accessory Anteroinferior Tibiofibular Ligament as a Cause of Talar Impingement

Background A distal fascicle of the anteroinferior tibiofibular ligament has been reported as a possible cause of anterolateral ankle impingement. Hypothesis This fascicle represents an independent accessory ligament in the anterior aspect of the inferior tibiofibular syndesmosis. Study Design Descriptive anatomical study. Methods The inferior tibiofibular syndesmosis was exposed in 24 fresh-frozen cadaveric ankles. Morphological characteristics of the inferior tibiofibular ligaments and interactions between the anterior ligaments and the talus were investigated in different degrees of ankle motion. Results A separate accessory anterior ligament was identified in 22 specimens. Its orientation was parallel and distal to the anterior tibiofibular ligament, from which it was separated by a fibrofatty septum. Its length ranged from 17 to 22 mm, its thickness from 1 to 2 mm, and its width from 3 to 5 mm. Impingement of this ligament against the talar dome was documented in all specimens in neutral ankle position, with bending of the ligamentous bands in dorsiflexion. Distraction maneuvers reproducing traction during arthroscopic approaches relieved contact. Conclusions An accessory anteroinferior tibiofibular ligament with distinct anatomical features was recognized. Clinical Relevance Based on its increased incidence in the cadaver ankles, the accessory ligament reflects a normal anatomical finding. Nevertheless, it could lead to anterolateral impingement in cases with coexistent ankle instability.

The fate of the syndesmosis in type C ankle fractures: a cadaveric study

Ankle fractures that involve a fracture of the fibula above the syndesmosis (AO type C) associated with a medial lesion are always said to indicate rupture of the inferior tibiofibular syndesmosis. This study shows that fresh cadaver ankles subjected to a combination of abduction and direct lateral force over the shaft of the fibula consistently produce displaced bimalleolar ankle fractures without disruption of the inferior tibiofibular syndesmosis. The results of this study suggest that the presence of an AO type C ankle fracture does not necessarily indicate diastasis of the inferior tibiofibular joint and, therefore, internal fixation of the syndesmosis of the fracture may not be indicated.