Syndesmosis Fixation Research Articles

Tibiotalar Joint Contact Mechanics Following Syndesmosis Fixation with Screws Versus a Flexible Fixation Device (TightRope™)

Category:Ankle, Arthroscopy, TraumaIntroduction/Purpose:Background: A shift and increase in mean tibiotalar contact pressure has been demonstrated in simulated syndesmotic injuries. The effect of screw fixation and/or suspensory fixation on restoration of pressure mechanics in the setting of a syndesmotic injury remains largely unknown.Hypothesis/Purpose:The purpose of this study is to examine the contact mechanics of the tibiotalar joint following syndesmosis fixation with screws versus a flexible fixation device for complete syndesmotic injury.Methods:Six matched pairs of cadaveric below knee specimens were randomly assigned fixation with either two 3.5 mm cortical screws or two TightRopes™ (Arthrex). Motion capture trackers were fixed to the tibia, fibula, and talus and a pressure sensor was placed in the tibiotalar joint. Each specimen was first tested intact with an axial compressive load followed by external rotation torque while maintaining axial compression. The syndesmosic ligaments were then completely sectioned and subsequently repaired with either two TightRopes™ or two screws and the protocol was repeated. Mean contact pressure (MCP), peak pressure (PP), reduction in contact area (CA), translation of the center of pressure (COP), and relative talar and fibular motion were calculated. Specimens were then cyclically loaded in external rotation to failure. Comparisons were made using paired t-tests and/or Welch’s t-tests.Results:No differences in MCP, PP, or CA were observed between the intact and instrumented states during AL alone for either group. MCP relative to intact testing was increased in the screw group at 5 Nm (4.8±4.1 MPa vs 3.6±0.8 MPa, p=0.033) and 7.5 Nm torque (6.2±1.4 MPa vs 4.2±1.2 MPa, p=0.024). Likewise, PP was increased in TightRope™ group at 7.5 Nm torque (14.4±3.1 MPa vs 10.8±1.6 MPa, p=0.046). There was no change in COP in the TightRope™ group at any threshold; however, at every threshold tested there was significant medial and anterior COP translation in the screw group relative to the intact state.Conclusion:Either screws or TightRope™ fixation is adequate with AL alone. With lower amounts of torque, the TightRope™ group exhibits contact and pressure mechanics that more closely match native mechanics.

Validation of the Center-Center Technique for Intraoperative Syndesmosis Fixation Alignment

Category:AnkleIntroduction/Purpose:Distal tibiofibular syndesmosis sprain has been reported among 13% to 23% of all ankle fractures, often requiring surgery. However, post-operative malreduction rates have been reported to range from 0 to 54%. Optimal reduction is a significant predictor of overall functional outcome.The centroids of the tibia and fibula align the theoretically ideal axis of syndesmosis fixation alignment. The “Center-Center” method for syndesmosis fixation is a recently described intraoperative technique for aligning the central axes of the tibia and fibula on the ankle lateral fluoroscopic view, seemingly aligning the centroids. There is a lack of validation and outcomes data to support this technique.This study was performed in order to determine how reliably the ”center-center” technique aligns with the centroid axis of the fibula and tibia.Methods:This was a quantitative descriptive study utilizing 30 axial computed tomography scans from July 1, 2016 to June 30, 2018. Eighteen males and 12 females were included with an average age of 44-years-old. CT measurements were made using Visage 7. Three observers measured the maximum difference in degrees between the Center-Center and Centroid measurements at 10 mm, 20 mm, and 30 mm proximal to the tibial plafond for each patient. The Center-Center axis was established by internally rotating the CT image until the fibula aligned within the center of the tibia. The centroid measurement was established using a tool that calculated the centroid of each bone. Finally, the difference in external rotation required to obtain the Center-Center measurements were observed at levels 10 mm versus 20 mm, 20 mm versus 30 mm, and 10 mm versus 30 mm.Results:The Center-Center and Centroid axes were highly consistent within and between subjects and levels, differing on average by a mean 0.39 degrees (95% CI 0.29 to 0.49 degrees) across all comparisons. These axes externally rotated a mean 3.10 degrees (95% CI 2.56 to 3.64 degrees) from 10 mm to 20 mm and a mean 2.72 degrees (95% CI 2.35 to 3.09 degrees) from 20 mm to 30 mm. There were no statistically significant differences in the mean values obtained between observers for any axis at any height (p-value range 0.4 to 1.0) and intraclass correlation indicated excellent to near perfect interobserver agreement (ICC range, 0.876 to 0.988).Conclusion:The Center-Center technique consistently and closely aligns the fibula and tibia along the Centroid axis. These two axes externally rotate approximately 3 degrees for each 10 mm above the plafond. The Center-Center technique may offer the highly accurate means sought for achieving accurate and consistent intraoperative syndesmosis fixation alignment due to its highly consistent relationship to the Centroid axis. Surgeons should be aware of the external rotation of these axes between heights as the axes externally rotated a mean 3 degrees for each 10 mm height increase. Failure to correct limb rotation for each height could result in iatrogenic malreduction.

Ankle joint contact loads and displacement in syndesmosis injuries repaired with Tightropes compared to screw fixation in a static model

BackgroundThe effect of syndesmotic fixation on restoration of pressure mechanics in the setting of a syndesmotic injury is largely unknown. The purpose of this study is to examine the contact mechanics of the tibiotalar joint following syndesmosis fixation with screws versus a flexible fixation device for complete syndesmotic injury. MethodsSix matched pairs of cadaveric below knee specimens were dissected and motion capture trackers were fixed to the tibia, fibula, and talus and a pressure sensor was placed in the tibiotalar joint. Each specimen was first tested intact with axial compressive load followed by external rotation while maintaining axial compression. Next, syndesmotic ligaments were sectioned and randomly assigned to repair with either two TightRopes® or two 3.5 mm cortical screws and the protocol was repeated. Mean contact pressure, peak pressure, reduction in contact area, translation of the center of pressure, and relative talar and fibular motion were calculated. Specimens were then cyclically loaded in external rotation and surviving specimens were loaded in external rotation to failure. ResultsNo differences in pressure measurements were observed between the intact and instrumented states during axial load. Mean contact presure relative to intact testing was increased in the screw group at 5 Nm and 7.5 Nm torque. Likewise, peak pressure was increased in the TightRope group at 7.5 Nm torque. There was no change in center of pressure in the TightRope group at any threshold; however, at every threshold tested there was significant medial and anterior translation in the screw group relative to the intact state. ConclusionEither screws or TightRope fixation is adequate with AL alone. With lower amounts of torque, the TightRope group appears to have contact and pressure mechanics that more closely match native mechanics.

Bimalleolar Ankle Fracture With Syndesmotic Sprain: ORIF and Suture-Endobutton Repair

Syndesmosis sprain is not uncommon in unstable ankle fractures. Surgical stabilization of the syndesmosis can be achieved with either trans-syndesmotic screws or a suture-endobutton device. The suture-endobutton provides for potential advantages including more anatomical mobility of the joint, quicker return to weight-bearing, and no need for implant removal. In this article, we describe the indications and surgical technique for management of a bimalleolar ankle fracture requiring repair of the syndesmosis. This technique focuses on methods of intraoperative reduction and assessment using fluoroscopic imaging of the contralateral ankle for reference. We also demonstrate the use of a suture-endobutton for syndesmosis fixation.

A cadaveric study investigating the role of the anterior inferior tibio-fibular ligament and the posterior inferior tibio-fibular ligament in ankle fracture syndesmosis stability

BackgroundThis cadaveric study aimed to investigate the role AITFL and PITFL have on preventing talar shift in ankle fractures, as well as investigating the role of AITFL reconstruction in preventing talar shift. MethodsTwelve lower limb cadavers were used. Talar shift was measured following: Step 1- no ligaments cut; Step 2- entire deltoid ligament division; Step 3- group A (5 specimens) PITFL cut whilst group B (7 specimens) AITFL cut; Step 4- group A had AITFL divided whilst group B had PITFL cut. Reconstruction of the AITFL was performed using part of the superior extensor retinaculum as a local flap. Measurement of talar shift was then repeated. ResultsWith no ligaments divided, mean talar shift was 0.8mm for group A and 0.7mm for group B. When the deltoid ligament was divided, mean talar shift for group A was 4.8mm compared to 4.7mm in group B (P=1.00). The mean shift in group A after PITFL division was 6.0mm, increasing the talar shift by an average of 1.2mm. In group B after AITFL division mean talar shift was 8.3mm (P=0.06), increasing talar shift by an average of 3.6mm. After division of the second tibiofibular ligament, mean talar shift in group A measured 10.0mm and in group B was 10.9mm (P=0.29). Three times more talar shift occurred after the AIFTL was divided compared to the PITFL (P=0.06). ConclusionConsequently, repairing the PITFL in isolation (for example by fixation of a posterior malleolus avulsion fracture) may not adequately prevent talar shift; we feel consideration should also be given to reconstruction of the AITFL to augment the syndesmosis fixation, which may provide a stronger restoration of ankle stability.Level of Clinical Evidence: 5.

Fracture of a Heterotopic Ossification of the Syndesmosis in a Collegiate Football Player: A Case Report

Objective: Present a clinical case detailing the assessment and management of a collegiate football player suffering from the fracturing of a heterotopic ossification of the syndesmosis. Background: Heterotopic ossifications are not uncommon following surgical fixation of the tibiofibular syndesmosis. Typically, properly healed fibular fractures do not result in further complications associated with heterotopic ossification. Treatment: A 21-year-old collegiate football player (1.8 m, 77.1 kg) reported to the athletic training staff complaining of acute lateral ankle pain following a plant and twist mechanism while running receiving routes. Initial evaluation led to a diagnosis of a syndesmotic ankle sprain, with a plan to pursue conservative management. When patient was unable to participate in the following practice due to intensity of pain, the patient was referred for x-rays a revealed poorly healed Weber Type C fracture that had been mislabeled as a Maisonneuve fracture at the patient’s previous university. This previous injury led to a heterotopic ossification of the syndesmosis that had fractured during the more recent injury. With this new diagnosis, the patient consented to conservative treatment that allowed the patient to return to football activities the following offseason. Uniqueness: While heterotopic ossification of the ankle syndesmosis has been reported in literature, there has yet to be extensive research on the condition. Generally, when these ossifications become symptomatic best practices involve surgical removal. In spite of presenting with symptoms, the patient was able to return to full participation following conservative treatment. Conclusion: When providing patient care, accurate diagnosis is crucial to optimal outcomes. Caring for patients in a collegiate setting presents a unique number of instances of patient care transfer, which may make previous misdiagnosis hard to recognize. Diligent health care practitioners should always ensure that a comprehensive medical history is obtained in order to make an accurate assessment.

Syndesmosis assessment in postoperative patients subjected to surgical treatment of supra-syndesmotic fracture

Objective: To demonstrate the patterns of syndesmosis reconstruction in ankle fractures via the measurement of pre-established and universally accepted parameters. Methods: In a retrospective study, fractures with radiographic images obtained during the postoperative period showing fixation of the distal tibiofibular syndesmosis were selected. After this selection, fracture reduction and syndesmosis fixation were evaluated by measuring radiographic parameters in the selected cases. Results: Twenty-three patients (63.8%) were male. Fourteen fractures (38.8%) were operated on by a senior surgeon (foot and ankle specialist). All syndesmoses were fixed with only 1 screw, and 35 patients (97.2%) had syndesmosis fixation involving 3 cortices. The mean syndesmosis fixation height from the articular surface was 2.20cm. Four fractures (11.1%) presented radiographic signs of medial ligament reconstruction. Regarding measurement of the tibiofibular space, in the anteroposterior (AP) view, 33 patients (91.6%) had values within the normal range. Regarding the tibiofibular overlap, in the AP view, 19 patients (52.7%) had measurements with values greater than 10mm (normal). In the evaluation of tibiofibular overlap, in the true AP view, all patients (100%) presented measurements greater than 1mm (normal). Regarding the measurement of the talocrural angle, only 1 patient did not have normal parameters. Regarding the medial clear space, only 2 patients (5.5%) had values above normal during the postoperative period. Conclusion: The adoption of objective parameters, in a standardized manner and relative to the contralateral side, adds additional value to the evaluation and ensures an accessible and reproducible method for the evaluation of these injuries. Level of Evidence II; Prognostics Studies; Retrospective Study.

Tomographic control of sindesmosis reduction after surgical fixation

Objective: To determine percentages of types A (flat) and B (concave) of the distal tibiofibular joint in patients with ankle fractures or chronic ligament instabilities, with syndesmosis lesions; check the shape of the fixation and position of the fibula in this joint; to identify poor fibular reduction and its frequency in types A and B; patients according to the AOFAS criteria. Methods: 104 patients surgically treated with syndesmosis fixation underwent clinical evaluation using AOFAS functional criteria and tomographic exams to classify the distal tibiofibular joint in types A or B and evaluated the poor position of the fibula in this joint. Results: Distal tibiofibular joint type A was present in 27 ankles and type B in 77. Non-anatomical reduction of the fibula (17 ankles) was more frequent in type A than in type B and more frequent in fractures than in instabilities. The AOFAS score was 91.79 points in the 87 patients with good reduction and 86.76 points in the 17 patients with poor fibula reduction. Conclusion: Distal tibiofibular joint type B was more frequent than type A (p=0.00001); there was poor reduction of the fibula in this joint in 17 ankles (16.34%). Poor fibula reduction was more frequent in fractures than in instabilities (p=0.006). The poor reduction was more constant in type A than in type B, without statistical significance (p=0.34). The AOFAS score was 91.79 points in patients with good reduction and 86.76 points in patients with poor fibula reduction in the distal tibiofibular joint. Level of Evidence IV; Therapeutic Studies; Case Series.

Biomechanical Comparison of 3 Syndesmosis Repair Techniques With Suture Button Implants.

Background:Suture button fixation of syndesmotic injury is growing in popularity, as it has been shown to provide adequate stability in a more cost-effective manner than screw fixation while allowing more physiologic distal tibiofibular joint motion. However, the optimal repair technique and implant orientation have yet to be determined.Purpose/Hypothesis:The purpose of this study was to biomechanically compare 3 suture button construct configurations/orientations for syndesmosis fixation: single, parallel, and divergent. The authors hypothesized that all 3 methods would provide adequate stabilization but that the divergent technique would be the most stable.Study Design:Controlled laboratory study.Methods:The fixation strengths of 3 stabilization techniques with suture button devices were compared with 10 cadaveric legs each (N = 30). Ankle motion under cyclic loading was measured in multiple planes: first in the intact state, then following simulated syndesmosis injury, and then following fixation with 1 of 3 randomly assigned constructs—1 suture button, 2 suture buttons in parallel, and 2 divergent suture buttons. Finally, axial loading with external rotation was applied to failure.Results:All syndesmotic fixation methods provided stability to the torn state. There was no statistically significant difference among the 3 fixation techniques in biomechanical stability. Failure most commonly occurred through fibular fracture at supraphysiologic loads.Conclusion:Suture button implant fixation for syndesmotic injury appears to provide stability to the torn syndesmosis, and the configuration of the fixation does not appear to affect the strength or security of the stabilization.Clinical Relevance:This study provides further insight into the biomechanics and optimal configuration of suture button fixation of the torn syndesmosis. Based on these results, the addition of a second suture button may not significantly contribute to immediate postoperative stability.

ХИРУРГИЧЕСКОЕ ЛЕЧЕНИЕ ПЕРЕЛОМОВ ЛОДЫЖЕК С ПОВРЕЖДЕНИЕМ ДИСТАЛ ЬНОГО МЕЖБЕРЦОВОГО СИНДЕСМОЗА. СТАТИЧЕСКАЯ И ДИНАМИЧЕСКАЯ ФИКСАЦИЯ МЕЖБЕРЦОВОГО СИНДЕСМОЗА, СРАВНЕНИЕ РЕЗУЛЬТАТОВ

Introduction: a dynamic system for fixation of distal tibiofibular articulation damages in recent times cut a swath among experts in traumatology and orthopedicsarea since at a high frequency of occurrence of such damage its classical static fixation by position screw has a number of disadvantages with consequent complica-tions. A dynamic fixation provides physiologic micromotion intercostal articulation with maintenance of adequate repositioning that assumes its advantage over static fixation.a e-mail: Fedor_lazko@mail.rub e-mail: Semeonoff.aleks2011@yandex.ruc e-mail: Okneller90@gmail.comd e-mail: Ramidisser@mail.rue e-mail: Dr.Romanov67@mail.ruf e-mail: Pauldemon94@gmail.comstudy purpose: comparison of clinical and radiological results of static and dynamic fixation methods of the distal tibiofibular articulation instability.Methods: Was carried out an effectiveness analysis of treatment of 42 patients having B and C-types malleolar fractures according to AO/ASIF classification withtibiofibular syndesmosis damage, in settings of the traumatology and orthopedic department of the State Clinical Hospital No. 67 named after Vorokhobov duringthe period from 2016 to 2018. Patients were divided into two groups depending on the type of syndesmosis fixation: 21 patients were included into dynamic fixation group and 21 patients were included into static fixation group. Control examinations were carried out at 1.5; 3; 6 and 12 months after surgery. The average follow-up period was 12 months. Clinical and x-ray methods were used, scores questionnaires were filled in (AOFAS, FADI, OMAS).study results: evaluation of the obtained data showed that tendency to better clinical and radiologic results is reported in the dynamic fixation group.Conclusion: the dynamic fixation of distal tibiofibular articulation damages is a good alternative to its classical static fixation by position screw.

Treatment of Maisonneuve fracturewitharthroscopic-assistant plate-screw fixation of the syndesmosis

Objective To investigate the effect of the treatment for Maisonneuve fracture with arthroscopic-assistant plate-screw fixation ofsyndesmosis. Methods From January 2015 to December 2016, totally 22 patients with Maisonneuve fracture were treated in Shanghai Jiao Tong University Affiliated Six People′s Hospital. Eleven patients in minimal invasive surgery (MIS)group were treated by the arthroscopic-assistant plate-screw fixation ofthe syndesmotic injury. Another 11 patients in the control group were performed a classic syndesmosis screw fixation. Plain radiographic examination was carried out during the follow-up. Functional evaluation was measured according to the American Orthopedic Foot Ankle Society (AOFAS) ankle hindfoot score and the Visual analogue scale(VAS). A t test was applied for the statistic analysis of post-operative outcome between the two groups at 6th and 12th month. Results The patients were followed for an average 18 months (range from 12 to 24 months) except one of MIS group.The X-ray demonstrated the solid bone union occurred on the 12th week in MIS group and 12.5th week in the control group. The implants of syndesmosis were removed at 12th week post-operatively. No cases of re-diastasis occurred during the follow-up. There was significant difference with in the groups. In the MIS group, the AOFAS ankle hindfoot score was (85.9±4.1) points at 6th month post-operatively, and increased to (90.8±3.7) at 12th month (P<0.05). VAS score was (2.4±1.2) at 6th month and (1.1±0.7) at 12th month after the operation(P<0.05). In the control group, the AOFAS ankle hindfoot score was (81.1±4.7) points at 6th month after operation, and increased to (89.1±3.4) at 12th month after operation (P<0.05). VAS score was (3.2±1.3) at the 6th month and (1.0±1.0) at the 12th month after operation(P<0.05). However, for the outcome comparison between the two groups, only the AOFAS ankle hindfoot score of 6th month post-operatively in MIS group was better than the control group (P<0.05), other results, had no significant difference.Nocomplications of implant failure, nonunion, malunion or post-traumatic arthritis were occurred during the follow-up. Conclusion The treatment of Maisonneuve fracture by arthroscopic-assistant plate-screw fixation proved to have an advantage of minimal invasion and accurate reduction and fixation, which is a safe and effective surgical method. Key words: Ankle joint; Fracture; Fracture fixation, internal; Arthroscopes

Biomechanical Comparison of Syndesmotic Repair Techniques During External Rotation Stress

The purpose of this study was to compare mechanical behavior of conventional syndesmosis fixation devices with new anatomic repair techniques incorporating various repair augmentations to determine which approach would return rotational ankle mechanics closer to those of an intact ankle. Ten pairs of fresh-frozen through-the-knee cadaveric lower limbs were subjected to 7.5 Nm of external rotation torque while under 750 N of axial compression. After testing specimens intact and with the deltoid and syndesmotic ligament complexes completely destabilized, specimens underwent syndesmotic fixation using a screw, a suture button construct, a prototype structurally augmented flexible trans-syndesmotic fixation device, or the prototype device plus suture repairs of the anterior-inferior tibiofibular ligament and deep deltoid ligament. Syndesmotic repair devices were exchanged between tests so that each specimen was tested with 2 different fixation techniques. Whole-foot rotation angles at 7.5 Nm of applied torque were measured for comparison of the different repair strategies, and reflective markers mounted on the tibia, fibula, and talus were used to track translations and rotations of the talus and the fibula relative to the tibia during testing. Syndesmotic destabilization significantly ( P < .001) increased whole-foot, talus, and fibula rotation in an axial plane and posterior fibula translation under 7.5 Nm of torque. Neither the suture button nor the augmented flexible trans-syndesmotic fixation device reduced those increases. Screw fixation or addition of anatomic ligament repairs to the augmented flexible fixation device successfully reduced axial plane rotations and sagittal plane translations to near intact levels. Flexible trans-syndesmotic fixation alone was found to be insufficient for restoring rotational stability to the ankle/talus or preventing sagittal plane displacement of the fibula. Repairs to simulate anatomic structures disrupted during a syndesmosis injury were required to restore rotational stability to the foot when using flexible trans-syndesmotic fixation that may have clinical applicability.

Effect of Deltoid Ligament Repair versus Syndesmosis Fixation on Ankle Joint Stability After Bimalleolar Equivalent Ankle Fracture

Category: Trauma Introduction/Purpose: The current standard for stabilization of the talus within the ankle mortise after bimalleolar equivalent ankle fracture is open reduction and internal fixation (ORIF) of the lateral malleolus followed by syndesmotic screw fixation of the syndesmosis. Syndesmotic fixation may be associated with complications such as mal-reduction, joint stiffness, altered ankle biomechanics, and potential additional surgery for hardware removal. Consequently, some surgeons advocate ORIF of the lateral malleolus in conjunction with deltoid ligament repair rather than syndesmosis fixation. To our knowledge, clinical reports of this treatment option lack biomechanical evidence to support this approach. The purpose of this investigation was to compare ankle joint stability and contact pressures in a bimalleolar equivalent ankle fracture model treated with trans-syndesmotic screw fixation versus deltoid ligament repair. Methods: We prepared and tested seven fresh frozen cadaveric whole lower leg specimens with an undisturbed proximal tibiofibular joint. We tested each leg was tested under five conditions: (1) intact, (2) syndesmosis disrupted and deltoid ligament sectioned, (3) syndesmosis reduced w/ screw fixation, (4) deltoid repaired, and (5) both syndesmosis and deltoid ligament repaired. Under a nominal axial load, we applied controlled anterior, posterior, lateral, and medial drawer stresses to the foot using a custom-built testing apparatus and documented the resulting talar translation relative to the tibia. We also applied controlled internal and external rotation stresses to the ankle model and measured the provoked ankle joint rotations. In each condition, we measured peak ankle contact pressure (PACP) using a Tekscan pressure sensor under a physiologic axial load simulating single-limb stance. Results: Concurrent disruption of the syndesmosis and the deltoid ligament significantly (p&lt;.05) increased anterior drawer, lateral drawer, and internal and external rotation. Subsequent deltoid repair significantly reduced anterior displacement to normal levels, but syndesmosis fixation did not. Lateral drawer was not significantly corrected until both deltoid ligament and syndesmosis were repaired. Deltoid repair and syndesmosis fixation each reduced internal rotation significantly, with further reduction to normal levels when both were repaired. External rotation remained elevated relative to the intact condition regardless of which structures were repaired. Deltoid repair and syndesmosis fixation achieved similar levels of posterior, lateral and medial drawer reduction, but these measures did not approach normal values until both were repaired. No significant differences in PACP were identified among the five tested conditions. Conclusion: Isolated repair of the deltoid ligament after a bimalleolar equivalent ankle fracture achieves markedly better anterior displacement stability than does fixation of the syndesmosis with a screw. Under the described testing conditions, the two procedures offer similar posterior, medial, and lateral talar displacement stability and similar levels of internal and external rotational stability. Given the complications that may be associated with rigid syndesmotic screw fixation, our investigation suggests that deltoid repair may represent a reasonable alternative to syndesmosis fixation.

An Accuracy of Syndesmotic Reduction by Direct Visualization Technique

Category: Trauma Introduction/Purpose: Syndesmotic injury is commonly seen associated with acute ankle fracture. Syndesmotic malreduction was proven be a poor prognostic factor. Many methods have been purposed to assess the quality of reduction such as direct visualization, comparing radiographic parameters to contralateral ankle fluoroscopy, and intra-operative computed tomography. In this study, we demonstrated syndesmotic malreduction rate using bilateral CT after using direct visualization technique for syndesmotic fixation. Methods: A prospective case series of 34 patients (13 left and 21 right sides) with an average age of 42 years who had rotational ankle fractures with syndesmotic injury confirmed by arthroscopic examination. All patients were treated with an open reduction and internal fixation of distal fibula using either 1/3 tubular plate or distal anatomical locking plate. Syndesmosis was fixed by one or two of 3.5-mm cortical screw with three or four cortices. Before syndesmotic fixation, syndesmotic reduction is made by using a large point reduction clamp and quality of the reduction was checked by direct visualization at anterior tibiofibular line. The accuracy of syndesmotic reduction is then evaluated by post-operative bilateral CT. A widening of distance between anterior tibia and fibular at 1-cm above the ankle joint more than 2 mm compared to uninjured sides considered a malreduction of syndesmosis. Results: The accuracy of syndesmotic reduction was 97.1 percent (33/34) compare to contralateral ankle. An average of BMI was 27.2 and an average of operative time was 98.2 minutes. One malreduction, was diagnosed on the criteria of a 2 mm difference from the contralateral side occurred due to a small fragment interposition at the syndemosis. This patient underwent revision surgery to remove the fragment and then fixation of syndesmosis with same manner to achieve anatomical reduction. In all cases, the screws are removed at 12 weeks. Neither breakage nor migration of screws is observed and no wound or nerve complications following this technique. Conclusion: A syndesmotic fixation using direct visualization technique demonstrate lower rate of malreduction as demonstrated by poster-operative bilateral CT scan and no complications. This technique is effective, safe, and should be considered for treatment of syndesmotic injury associated ankle fracture.

Improved Reduction of the Tibiofibular Syndesmosis with Tightrope Compared to Screw Fixation

Category: Trauma Introduction/Purpose: Flexible fixation of the tibio-fibular syndesmosis is designed to allow increased ankle motion and to potentially improve clinical outcomes compared to screw fixation. Flexible fixation has also been suggested to improve the rate of anatomic reduction. This randomized, multi-center study was designed to compare the rate of malreduction following treatment of high fibular fractures associated with syndesmosis injury with open reduction and internal fixation with either two fully threaded screws or one knotless Tightrope device. Methods: 101 patients from eleven sites were randomized and underwent operative fixation of their AO/OTA 44-C injury between June 2015-16. All patients demonstrated radiographic syndesmosis diastasis or instability following malleolar bony fixation. Open syndesmosis reduction was performed in all cases. Fixation was randomized to either Tightrope (T) or screws (S). Surgical techniques and rehabilitation were standardized. Follow-up at 2 and 6 weeks, 3, 6 and 12 months. The primary outcome measure was the rate of malreduction based on bilateral ankle CT scan results at 3 months post fixation. Secondary outcome measures included adverse events, reoperation, and validated functional outcomes including the EQ5D, OM Score, FADI, and WPAI. The estimated sample size required to detect a difference in reduction rate was 72 patients, but the estimated sample size required to detect a difference in functional outcome scores was 240 patients, suggesting the study was adequately powered for radiographic results only. Results: The rate of malreduction was 39% using screws compared to 15% using Tightrope (p = 0.028). Analysis of CT results was performed using a 2 mm translation or 10 degree rotation threshold for malreduction, and included fibular translation, syndesmosis distance, medial compression; and rotation. Patients in Group T had greater anterior translation compared to the contralateral limb (p=0.007) or Group S (p = 0.04). Group T syndesmoses also had greater diastasis compared to control limb (p=.005) and less fibular medialization compared to Group S (p = 0.05). Functional outcome measures demonstrated significant improvements but no differences between groups. FADI scores at each time interval were equivalent. The reoperation rate was higher in the screw group compared to Tightrope (30% vs 4%, p= 0.02). Conclusion: Treatment of tibio-fibular syndesmosis injury with the knotless flexible Tightrope device achieves lower rates of malreduction and reoperation compared to screw fixation.

Medial Structure Injury During Suture Button Insertion Utilizing “Center-Center” Technique for Syndesmotic Stabilization

Category: Ankle Introduction/Purpose: The “Center-Center” technique for syndesmosis fixation has been described as an improved and reliable technique for proper reduction of the syndesmosis during ankle fracture repair. Concurrently, the use of a flexible suture button is becoming an established means of syndesmotic stabilization. The purpose of this cadaveric study was to assess for medial structure injury during the placement of a suture button utilizing the “Center-Center” technique for ankle syndesmotic repair at 3 insertion intervals. Methods: Simulated open syndesmosis repair was performed on 10 cadaveric specimens. Three intervals were measured at 10 mm, 20 mm, and 30 mm proximal to the level of the distal tibial articular surface along the fibula. Proper longitudinal alignment of the “Center-Center” technique was completed under fluoroscopic guidance and was marked on the medial aspect of the tibia. The 3 intervals were drilled in the appropriate technique trajectory. The suture button was passed through each drill-hole interval. Using a digital caliper, the distance was measured from each suture button aperture with respect to the anterior tibial tendon, posterior tibial tendon, greater saphenous vein and nerve by single observer. Results: The average distance from the suture button to each anatomic structure was -2.61 ± 3.75 mm for the greater saphenous vein, -3.44 ± 6.82 mm for the saphenous nerve, 15.09 ± 4.02 mm for the anterior tibial tendon, and -21.70 ± 4.89 mm for the posterior tibial tendon. Direct impingement of the greater saphenous vein was seen in 11/30 (36.6%) interval measurements. Six of the 11 (54.5%) entrapment intervals occurred at the 10 mm drill hole. Conclusion: The results of the present study suggest the use of the “Center-Center” technique for syndesmotic repair with suture button application does involve risk of injury to the greater saphenous vein and saphenous nerve. These injuries could manifest as persistent lower extremity edema and paresthesias for injury to the saphenous vein and nerve respectively. The “Center-Center” technique with suture button fixation may warrant a minimal medial open dissection, prior to quadricortical drilling, for optimal placement to prevent neurovascular injury.

Surgical Implications of the Distal Tibia Morphology at the Incisura for Glenoid Augmentation

Objectives:Distal tibia allograft (DTA) glenoid augmentation has been introduced as a viable treatment approach for glenoid bone loss in conjunction with shoulder instability. An ideal graft has a flat or nearly flat lateral border of the tibia, allowing the surgeon to retain the lateral cortical bone for increased screw fixation (Figure 1A). DTA grafts with a deep concavity are difficult to prepare for fixation, as it is necessary to remove most of the cortical bone to create a flat contour of the graft (Figure 1B). Previous anatomic studies have sought to evaluate the morphology at the incisura as it pertains to syndesmosis fixation. No previous study has assessed the morphologic variation of the distal tibia at the incisura as it relates to graft dimensions for glenoid augmentation.Methods:Magnetic resonance images (MRI) of the ankle were reviewed over a 3 month period. Studies that met inclusionary criteria underwent morphology assessment to characterize the appearance and depth of the distal tibia at the incisura, both at the articular surface and the physeal scar, representing the typical depth of a DTA graft. Measurements were performed by two independent observers and inter-rater reliability was assessed. A three-part classification system was created reflecting the suitability of the distal tibial for glenoid augmentation. Type A grafts contained a flat contour of the lateral tibia, indicative of an ideal graft. Type B grafts had a slight concavity, with a central depth < 5 mm and were deemed acceptable grafts. Type C grafts had a deep concavity, with a central depth > 5 mm and were deemed unacceptable for glenoid augmentation. Statistical analysis was performed using univariate analyses to compare recorded patient demographics against acceptable morphology for glenoid augmentation.Results:101 patients were identified with 16 excluded, leaving 85 patients for study inclusion (53 male, 32 female, average 35.1 years ±10.3 years). Overall, 12 patients (14.1%) demonstrated a type A morphology, with an additional 61 patients (71.8%) having a type B morphology for a total of 85.9% with an acceptable specimens for glenoid augmentation. The inter-rater reliability was moderate to strong between measuring observers (0.793). Only gender has found to effect the likelihood of an acceptable graft with 100% of female patients having an acceptable morphology, compared to 77% of male patients (p=0.004).Conclusion:The morphology of the distal tibia at the incisura, as it relates to glenoid augmentation was variable in this patient cohort. 14.1% of patients demonstrated an ideal morphology for glenoid augmentation, with an additional 71.8% were deemed suitable for graft usage with only minor contouring necessary. 14.1% of patients were found to have an unacceptable morphology. Gender was a significant factor for predicting acceptable grafts, with 100% of female patients having an acceptable morphology. This information will help surgeons accept or reject grafts based on the knowledge of the epidemiology of the distal tibia morphology as it relates to glenoid augmentation.

Surgical treatment of patients with ankle joint fracture and damage of syndesmosis

Treatment of unstable ankle joint fractures with damage of syndesmosis is one of important problems in modern traumatology practice.Objective: to evaluate the results of surgical treatment of patients with ankle joint fractures and damage of syndesmosis due to analysis of functional ankle state and assessment of life quality in postoperative period.Methods: we analyzed the results of surgeries of 80 patients (18–67 y. o.) with ankle joint fracture and damage of syndesmosis. In all cases we made os­teosynthesis and restoring of syndesmosis stability with following course of rehabilitation, which was the same in our groups. In the main group 44 patients we used developed devices (modeling plates with polyaxial screws blocking for external malleous and tight loops for syndesmosis stabilization). In comparative group (36 patients) we used method АО/ASIF (for external malleous we used AO ⅓ and 1–2 cortical screws of 3.5 mm for syndesmosis fixation). We assessed the results of treatment in 3, 6, 12 months after surgery with 100 score Ankle-Hindfoot Scale AOFAS and SF-36 system.Results: it was established that in the early terms after surgery (3 mon.) in the main group the functional results were better according to AOFAS scale on 17 %. The quality of life according to SF-36 was also better: the signs of physical condition — 21 %, psychological — 7.4 %.Conclusions: suggested method combines stable osteosynthesis of external malleous fractures with stable dynamic fixation of syndesmosis, it allow in improve the life quality and to get excellent and good results in 95.5 % cases.

In Vivo CT Analysis of Physiological Fibular Motion at the Level of the Ankle Syndesmosis During Plantigrade Weightbearing.

Background. It is clear that motion at the syndesmosis occurs due to ranging of the ankle joint, but the influence of weightbearing with the foot in the plantigrade position is unclear. In vivo computed tomographic (CT) evaluation of the syndesmosis has not been previously described. The purpose of this study is to quantify physiological fibular motion at the level of the ankle syndesmosis in both weightbearing and nonweightbearing conditions with the foot in the plantigrade position. Methods. CT images were obtained from 9 normal healthy subjects using a weightbearing CT imaging system. The subjects were positioned in a nonweightbearing and weightbearing state with their foot in the plantigrade position. Fibular translation and rotation were measured from the axial CT images using previously validated techniques. Results. Both the average lateral and anteroposterior translation of the fibula between weightbearing and nonweightbearing states was minimal (0.3 mm and 0.2 mm, respectively). The largest difference in translation observed in either direction was 0.9 mm. An average of 0.5° was found for rotational differences of the fibula between weightbearing and nonweightbearing. Neither of the translational and rotational parameters reached statistical significance. Conclusion. In vivo CT analysis of the distal tibiofibular joint with an intact syndesmosis did not reveal statistically significant physiological motion between weightbearing and nonweightbearing conditions with the foot in plantigrade position. Our findings suggest that weightbearing accounts for little motion at the syndesmosis and supports further investigation into the role of early protected weightbearing after syndesmosis fixation. Levels of Evidence: Level III: Case-control study.

Stability in ankle fractures: Diagnosis and treatment.

Medial column (deltoid ligament) integrity is of key importance when considering the stability of isolated lateral malleolus ankle fractures.Weight-bearing radiographs are the best method of evaluating stability of isolated distal fibula fractures.Computed tomography (CT) scanning is mandatory for the assessment of complex ankle fractures, especially those involving the posterior malleolus.Most isolated trans-syndesmotic fibular fractures (Weber-B, SER, AO 44-B) are stable and can safely be treated non-operatively.Posterior malleolus fractures, regardless of size, should be considered for surgical fixation to restore stability, reduce the need for syndesmosis fixation, and improve contact pressure distribution.Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170057