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Syndesmotic injury

71 citationsUpdated Sep 2026

Overview

Syndesmotic injury diagnosis is often complex, and optimal management remains controversial [1]. Failure to diagnose and stabilize syndesmotic disruption adversely affects outcome [1]. Stable syndesmotic injuries do not require surgical stabilization and can be treated with protected weight bearing [3]. Nonsurgical management is used for stable ligamentous injuries without frank diastasis [20]. Unstable syndesmotic injuries require operative stabilization [3]. Surgical management is indicated for fractures with unstable syndesmotic injuries [20]. In type C ankle fractures, fixation of the syndesmosis is not indicated, as avoiding fixation prevents the complications associated with syndesmotic screws [2].

Intra-articular pathologies occur in up to 50% of patients with acute isolated, unstable syndesmotic injuries and necessitate additional treatment in 19% of patients [4]. Delayed surgical stabilisation of dynamically unstable syndesmotic injuries greater than 6 months is associated with significantly worse clinical function [5]. Timely identification and early referral of patients with potentially unstable syndesmotic injuries is recommended [5]. Accurate reduction and stable fixation of the syndesmosis are critical to maximize patient outcomes [32]. Malreduction is a significant predictor of poor functional results in syndesmotic injuries [32].

Current evidence for the treatment of chronic syndesmosis injuries is limited to prospective and retrospective case series [13]. Recommendations for surgical treatment are based only on level IV and V evidence [9]. Knowledge about syndesmotic injuries remains limited [9]. Future high-level studies are required to discern the most appropriate treatment strategy for chronic syndesmotic injuries of the ankle [11]. Certain patient groups have an increased risk of adverse events following the use of current surgical fixation methods for stabilizing the syndesmosis [12].

Anatomy & Pathophysiology

Anatomical Structures

The ankle syndesmosis consists of three primary structures: the anterior-inferior tibiofibular ligament, the posteroinferior tibiofibular ligament, and the interosseous membrane [43]. Only approximately 20% of the syndesmotic ligament is intra-articular [43]. A separate anterior-inferior tibiofibular ligament fascicle, known as the Bassett ligament, may be present and can contribute to syndesmotic impingement [43]. The interosseous membrane plays a critical role in weight transmission through the fibula [56]. In a biostatic model, one-sixth of the static load of the leg was carried by the fibula, a force generated by the fibula's articulation with the talus and possibly the inferior tibiofibular ligaments [78].

Pathomechanics

Syndesmotic injuries result from a combination of dorsiflexion and external rotation forces [37]. The syndesmosis ruptures in ankle fractures due to a torsional movement of the talus that forces the tibia and fibula apart, or as a result of a severe abduction force [56]. Syndesmotic diastasis requires the rupture of three strong ligaments and the interosseous membrane [56]. Severe syndesmotic injuries are associated with deltoid ligament disruption and fibula fracture [37]. Instability resulting from syndesmotic injury leads to lateral and rotatory displacement of the talus [37]. Stability of the loaded ankle is primarily due to the deltoid ligament, which exerts a restraining influence on external rotation of the talus [93].

Clinical Consequences

Untreated syndesmotic diastasis may result in persisting instability, pain, and progressive osteoarthritis [56]. Patients with radiographic evidence of syndesmosis widening demonstrated a poorer overall outcome at 5 years in a study of ankle fracture outcomes [56]. Injury to the ankle syndesmosis can result in persistent pain and dysfunction secondary to syndesmotic impingement [43]. Syndesmotic impingement most often involves the anterior tibiofibular ligament, with resulting synovitis and scarring along this ligament [43]. The accessory anteroinferior tibiofibular ligament is a normal anatomical finding that could lead to anterolateral impingement in cases with coexistent ankle instability [100]. Most studies found distinct characteristics of the incisura fibularis morphology associated with ligamentous ankle lesions, potentially due to lower osseous resistance against tibiofibular displacement [77].

Classification

Danis Weber (AO) Classification: This system categorizes ankle fractures based on the level of the fibular fracture into Type A (infrasyndesmotic), Type B (transsyndesmotic), and Type C (suprasyndesmotic) [124]. A more proximal fibular injury indicates a greater risk of syndesmosis disruption and ankle instability [124].

Sikka et al. Classification: The severity of syndesmotic injury can be classified in accordance with the classification proposed by Sikka et al. [26].

Other Considerations: An evidence-based diagnostic algorithm based on noninvasive diagnostics and an anatomy-based classification for acute syndesmotic instability has been presented [8]. Six exclusive injury patterns are defined based on lateral and syndesmotic ligament involvement, ranging from no injury to syndesmosis injury without lateral ligament injury [27]. Injury propagation in forced external rotation initiates with injuries to the medial ligaments, particularly the superficial deltoid, followed by propagation to either the syndesmotic or lateral ligaments, and finally to the interosseous membrane or the fibula [38].

Clinical Presentation

History and Mechanism

Syndesmotic injuries result from a combination of dorsiflexion and external rotation forces [37]. These injuries are easily missed and may have been previously overlooked or incorrectly diagnosed [45]. Pain is usually diffuse about the ankle and can be present anterolaterally proximal to the lateral ankle ligaments [45]. Patients commonly report pain while walking up hills, pivoting, or performing a single-leg heel raise [45]. Distal tibiofibular dislocation with an intact fibula may present with subtle clinical features [69]. In chronic presentations, persistent swelling, stiffness, push-off weakness, and subjective instability with normal stress tests are common [29]. Ongoing pain despite rest points toward syndesmotic pathology, whereas intermittent, pain-free intervals between sprains suggest lateral instability [29].

Physical Examination

If instability is present, the patient usually cannot bear weight [37]. Inspection reveals swelling and ecchymosis [37]. Tenderness is noted near the syndesmosis and deltoid ligament [37]. Pain is elicited with external rotation of the ankle [37]. A positive squeeze test is defined as pain at the syndesmosis when compressing the tibia and fibula at midcalf [37]. Patients with syndesmotic impingement have localized tenderness along the anterior syndesmosis, and symptoms increase with dorsiflexion and external rotation of the ankle [43]. Early red flags that heighten suspicion for syndesmotic injury include prolonged non-weight-bearing, extensive medial or proximal bruising, and marked early swelling [29].

Imaging and Diagnostic Findings

Plain radiography is the initial diagnostic modality. The AP view shows decreased tibiofibular overlap, while the mortise view shows increased tibiofibular clear space [37]. Normal tibiofibular clear space is less than 6 mm on either the AP or mortise ankle view [37]. Normal tibiofibular overlap is greater than 6 mm on the AP view and greater than 1 mm on the mortise view [37]. Tibial radiographs should be obtained to rule out a proximal fibula fracture (Maisonneuve fracture) [37]. In subtle cases, the diagnosis is confirmed by weight-bearing radiographs and stress radiographs in eversion and external rotation, with comparison to the opposite side [37].

Advanced imaging provides further characterization. CT may help evaluate the syndesmotic space, especially in chronic cases [37]. Isolated anterior syndesmosis diastasis without fracture is a rare entity that can be easily missed in routine X-rays, where computed tomography is useful for diagnosis in cases of clinical suspicion [40]. MRI may show subtle syndesmotic ligament injury [37]. MRI detected a posterior syndesmosis injury in 93.5% of patients acutely but became less reliable with time [16]. Although MRI can be used to confirm the diagnosis of a syndesmosis injury, it did not predict return to play in professional ice hockey players [25].

Quantitative assessment is critical for determining stability. The syndesmotic area is the most reliable parameter for assessing syndesmotic injuries as it increases in the presence of instability during weightbearing status [15]. Orthopaedic surgeons should consider using weightbearing cone-beam CT (WBCT) syndesmotic area measurements as an isolated, accurate, practical, and reliable marker of syndesmotic instability [42]. Traditional radiographic measurements should not be relied on solely for determining if the syndesmosis is intact and the ankle mortise is stable [47]. Intra-articular pathologies in acute isolated, unstable syndesmotic injuries occur in up to 50% of patients, with 19% necessitating additional treatment [4].

Stress testing interpretation requires caution. In a cohort of arthroscopically confirmed syndesmotic widening, most ankles had ≤5° of tilt on stress fluoroscopy, and only 13 of 34 ankles (38%) had a positive Cotton test [29]. A talar tilt ≥10 to 15° on stress films indicates lateral ligament instability and warrants stabilization, whereas minimal tilt (≤5°) should prompt syndesmotic evaluation rather than functional attribution [29].

Investigations

Clinical Examination: Diagnosis of syndesmotic injury is not straightforward, and failure to diagnose and stabilize syndesmotic disruption adversely affects outcome [1]. Initial diagnosis relies on physical examination, but further evaluation using imaging modalities such as weight-bearing CT and ultrasonography is necessary to determine instability [24]. The Chertsey test serves as an easy and reliable adjunct to ankle fixation surgery, clearly demonstrating syndesmosis injury and confirming accurate fibular reduction without the need for further radiological investigation or surgical intervention [129].

Plain radiography: Weight-bearing radiographs provide a more functionally accurate assessment of syndesmotic integrity than non-weight-bearing imaging and should be incorporated into routine diagnostic protocols, especially for active individuals and those with higher BMI [115]. The tibiofibular clear space is the most reliable plain radiographic parameter suggested to correlate with syndesmotic rupture [56]. However, cadaveric models have shown that no predictable increase in measurements on plain radiography can be found on sectioning of the syndesmotic ligaments [56]. Some normal individuals have such a shallow incisura that they have no radiographic tibiofibular overlap whatsoever [56]. Consequently, an increase in the tibiofibular clear space in comparison to the contralateral ankle may be more accurate than absolute values given the limitations of plain radiography [56].

Computed Tomography (CT): Orthopaedic surgeons should consider using WBCT syndesmotic area measurements as an isolated, accurate, practical, and reliable marker of syndesmotic instability [42]. CT was superior to simple radiography in predicting syndesmotic injury at the preoperative period in SER-type III and IV [114]. Syndesmotic joint volume measurements seem to be best suited to diagnose syndesmotic instability among patients with Weber B ankle fractures, compared with other two-dimensional and three-dimensional WBCT measurements [122]. Three-dimensional imaging may improve tibiofibular malreduction visualization in bimalleolar/trimalleolar/dislocated type Weber B fractures and in isolated type Weber C fractures with syndesmotic transfixation [126]. Applying external rotation during WBCT imaging may enhance diagnostic accuracy of subtle syndesmotic instability based on 3D measurements [119].

MRI: Pre-operative 3.0-T MRI demonstrated excellent accuracy in the diagnosis of syndesmotic ligament tears and allowed for the visualization of relevant individual syndesmosis structures [75]. MRI has been shown to provide a more accurate assessment of syndesmotic injury which correlates well with direct arthroscopic assessment [56]. MR arthrography may add further accuracy to the assessment of syndesmotic injury [56]. The oblique axial magnetic resonance imaging scan revealed that the prevalence of transverse ligament and posterior inferior tibiofibular ligament injuries in syndesmosis-injured ankles were 76.5 and 41.2%, respectively [125]. Although MRI can be used to confirm the diagnosis of a syndesmosis injury, it did not predict return to play in a population of professional ice hockey players [25]. The clinical diagnosis of Salter-Harris I fracture of the distal fibula was incorrect in 100% of cases; instead, MRI identified ligamentous sprains and/or bony contusions in almost 90% of patients [127].

Other Considerations: An evidence-based diagnostic algorithm based on noninvasive diagnostics and an anatomy-based classification for acute syndesmotic instability is presented [8]. Delayed surgical stabilisation (>6 months) is associated with significantly worse clinical function, and thus timely identification and early referral of those patients with potentially unstable syndesmotic injuries is recommended [5].

Treatment

Non-Operative

Stable syndesmotic injuries do not require surgical stabilization and are managed with protected weight bearing [3]. Conservative treatment is appropriate for stable syndesmosis lesions [21]. Most isolated trans-syndesmotic fibular fractures are stable and can be treated non-operatively [117]. In type C ankle fractures where the syndesmosis is stable, fixation of the syndesmosis is not indicated, thereby avoiding the complications associated with syndesmotic screws [2]. At long-term follow-up, nonoperative management of high ankle sprains without diastasis on imaging was associated with acceptable patient-reported functional outcomes and low rates of subsequent ankle injuries [22].

Operative

Indications: Unstable syndesmosis lesions require surgical procedures to avoid long-term disability and chronic instability [21]. Delayed surgical stabilisation (>6 months) is associated with significantly worse clinical function [5]. Accurate reduction and stable fixation of the syndesmosis are critical to maximize patient outcomes, as malreduction is a significant predictor of poor functional results [32].

Surgical Approach / Technique: The anatomical approach, which directly fixes broken fragments and repairs torn ligaments, is effective in reducing the rate of syndesmosis malreduction, increasing biomechanical strength, and avoiding the need for trans-syndesmotic fixation and its secondary removal [55]. Arthroscopy-assisted treatment of latent syndesmotic instability is an effective method, showing statistically significant improvement in AOFAS scores for pain and function at final follow-up [82]. Arthroscopic reconstruction of the posteroinferior tibiofibular ligament is minimally invasive and may avoid overtreatment of isolated syndesmotic ligament injuries [10].

Implant Selection: The functional outcome of acute syndesmotic injuries treated with a syndesmotic screw was good and mainly influenced by patient and fracture characteristics [6]. Suture-button treatment for acute isolated ankle syndesmotic injuries leads to favorable clinical and radiological outcomes with maintained ankle stability [34]. Flexible fixation was the preferred device choice for syndesmotic injury repair in a global survey of respondents [33]. Bolt fixation efficiently stabilises the syndesmosis during healing and provides reliable syndesmotic reduction [79]. Cadaveric and biomechanical studies support the use of syndesmotic screws in selected fractures with syndesmosis disruption, but definitive clinical application remains debated [18].

Post-Operative Care: Syndesmotic screw fixation allows for good functional outcomes regardless of removal timing, but retaining the screw increases the risk of subsequent screw breakage and osteolysis [14]. If removal on demand of the syndesmotic screw is non-inferior to routine removal in terms of functional outcome, this will offer a strong argument to adopt this as standard practice of care, meaning patients will not have to undergo a secondary procedure, leading to less complications and subsequent lower costs [28]. Sonography for syndesmotic screw removal has a similar operative time to fluoroscopy and eliminates radiation exposure, supporting its feasibility as an efficient and safe alternative [53]. Practitioners agree that after surgery patients will need physiotherapy to accelerate recovery and improve functional results [95]. Return to normal activity, including sport activities, may occur around four months post-operatively [95]. The need for immobilization after surgery is still a question open to debate, with some using cast immobilization for up to three weeks and others advocating only the use of a soft dressing [95]. The non-weightbearing period varies from surgeon to surgeon, with some authors authorizing full weight-bearing as tolerated around six weeks post-operatively [95]. Consensus had not been reached on the timing to start mobilization and physiotherapy [95].

Chronic Syndesmotic Injury: Chronic syndesmotic instability and chronic medial ankle instability are significantly associated with unsatisfactory outcomes in patients with chronic ankle instability [35]. Suture-button repair improves outcomes in arthroscopically diagnosed chronic syndesmotic injury despite low imaging sensitivity [29]. A talar tilt ≥10 to 15◦ on stress films indicates lateral ligament instability and warrants stabilization, whereas minimal tilt (≤5◦) should instead prompt syndesmotic evaluation rather than functional attribution [29]. Diagnostic arthroscopy of the syndesmosis is performed even when stress radiographs favor lateral repair, unless the clinical history and examination clearly exclude syndesmotic involvement [29]. Future high-level studies are required to discern the most appropriate treatment strategy(ies) for chronic syndesmotic injuries of the ankle [11].

Evidence Limitations: Knowledge about syndesmotic injuries is still limited as recommendations for surgical treatment are only based on level IV and V evidence [9].

Complications

Implant-related complications: Retaining a syndesmotic screw increases the risk of subsequent screw breakage and osteolysis [14].

Instability: Chronic syndesmotic instability is significantly associated with unsatisfactory outcomes in patients with chronic ankle instability [35]. Similarly, chronic medial ankle instability is significantly associated with unsatisfactory outcomes in patients with chronic ankle instability [35]. Syndesmotic instability was more prevalent than expected despite rigid fixation of the posterior malleolus in posterior pilon fractures [48].

Other Considerations: Delayed surgical stabilisation (>6 months) of dynamically unstable syndesmotic injuries is associated with significantly worse clinical function [5].

Recovery

Non-Operative Management: Stable syndesmotic lesions can be treated with conservative means [21]. Nonoperative management of high ankle sprains without diastasis on imaging was associated with acceptable patient-reported functional outcomes and low rates of subsequent ankle injuries at long-term follow-up [22].

Operative Management: Unstable syndesmotic lesions require surgical procedures to avoid long-term disability and chronic instability [21]. After surgical stabilization of an unstable syndesmotic injury, full weight bearing did not lead to syndesmotic diastasis in the early post-operative period [50]. Early weight-bearing and range-of-motion exercise improved early function but did not affect time to return to work after surgical fixation of unstable ankle fractures [52].

Functional Milestones: At mid-term follow-up, the operative group appeared to report higher levels of ankle-related function compared to non-surgical management, however these differences were not statistically significant [113]. One year after the procedure, roentgenograms showed stable ankles with a full range of motion [133]. Good results are achieved by anatomic reconstruction of the anterior syndesmosis, and all patients in this study would undergo the surgery again if necessary [30].

Other Considerations: Long-term functional outcomes at a mean of twenty-one years after pronation-external rotation ankle fractures treated with one or two syndesmotic screws were good to excellent in the great majority of patients despite substantial radiographic evidence of osteoarthritis in one-half of the patients [111]. The anterior tibio fibular distance widened after one year of syndesmotic screw removal [132]. Most respondents did not alter rehabilitation protocols based on injury severity, though considerable variability existed in return to activity times [33].

Key Evidence

  • [L5] Diagnosis of syndesmotic injury may not be straightforward, and optimal management remains controversial; however, failure to diagnose and stabilize syndesmotic disruption adversely affects outcome. [1] (10.5435/00124635-200706000-00002)
  • [L5] In such injuries fixation of the syndesmosis is not indicated, thus avoiding the complications of the syndesmotic screw. [2] (10.1016/s0020-1383(97)00010-7)
  • [L5] Stable syndesmotic injuries do not require surgical stabilization and can be treated with protected weight bearing, whereas unstable injuries require operative stabilization. [3] (10.1016/j.csm.2015.06.009)
  • [L3] Intra-articular pathologies in acute isolated, unstable syndesmotic injuries occur in up to 50% of patients, with 19% necessitating additional treatment. [4] (10.1007/s00167-020-06141-y)
  • [L3] Delayed surgical stabilisation (>6 months) is associated with significantly worse clinical function, and thus timely identification and early referral of those patients with potentially unstable syndesmotic injuries is recommended. [5] (10.1007/s00167-020-05962-1)
  • [L3] Overall, the functional outcome of acute syndesmotic injuries treated with a syndesmotic screw was good and mainly influenced by patient and fracture characteristics. [6] (10.1016/j.injury.2013.09.035)
  • [L1] These long-term results favour the use of suture button when treating an acute syndesmotic injury. [7] (10.1302/0301-620x.102b2.bjj-2019-0692.r2)
  • [L1] An evidence-based diagnostic algorithm based on noninvasive diagnostics and an anatomy-based classification for acute syndesmotic instability is presented. [8] (10.1530/eor-23-0097)
  • [L4] Knowledge about syndesmotic injuries is still limited as recommendations for surgical treatment are only based on level IV and V evidence. [9] (10.1302/2058-5241.2.160084)
  • [L5] Furthermore, in contrast to the standard syndesmotic treatment modalities, it is minimally invasive, as isolated syndesmotic ligament injuries may be overtreated in such cases. [10] (10.1016/j.eats.2024.103418)
  • [L1] Future high-level studies are required to discern the most appropriate treatment strategy(ies) for chronic syndesmotic injuries of the ankle. [11] (10.1016/j.arthro.2013.07.048)
  • [L3] Certain patient groups have an increased risk of adverse events following the use of current surgical fixation methods for stabilizing the syndesmosis. [12] (10.1016/j.injury.2019.12.011)
  • [L1] The current evidence on the treatment of chronic syndesmosis injuries in the ankle is limited to prospective and retrospective case series. [13] (10.1007/s00167-013-2515-y)
  • [L3] Syndesmotic screw fixation allows for good functional outcomes regardless of removal timing, but retaining the screw increases the risk of subsequent screw breakage and osteolysis. [14] (10.1016/j.injury.2006.02.003)
  • [L1] The syndesmotic area is the most reliable parameter for assessing syndesmotic injuries as it increases in the presence of instability during weightbearing status. [15] (10.1097/corr.0000000000002171)
  • [L3] MRI detected a posterior syndesmosis injury in 93.5% of patients acutely but became less reliable with time. [16] (10.1007/s00167-019-05581-5)
  • [L5] This algorithm needs to be further validated in patients with suspected traumatic syndesmotic instability. [17] (10.2106/jbjs.24.00199)
  • [L5] Cadaveric and biomechanical studies support the use of syndesmotic screws in selected fractures with syndesmosis disruption, but definitive clinical application remains debated. [18] (10.5435/00124635-199705000-00006)
  • [L5] Nonsurgical management is used for stable ligamentous injuries without frank diastasis, while surgical management is indicated for fractures with unstable syndesmotic injuries. [20] (10.5435/jaaos-d-13-00135)
  • [L5] Stable syndesmosis lesions can be treated with conservative means, while unstable lesions require surgical procedures to avoid long-term disability and chronic instability. [21] (10.1177/2325967121s00851)
  • [L4] At long-term follow-up, nonoperative management of high ankle sprains without diastasis on imaging was associated with acceptable patient-reported functional outcomes and low rates of subsequent ankle injuries. [22] (10.1177/03635465241271593)
  • [L5] Initial diagnosis of syndesmotic injury is based on physical examination, but further evaluation using imaging modalities like weight-bearing CT and ultrasonography is necessary to determine instability. [24] (10.5435/jaaos-d-20-01350)
  • [L3] Although MRI can be used to confirm the diagnosis of a syndesmosis injury, it did not predict return to play in this population. [25] (10.1177/2325967119871578)
  • [L4] [26] (10.1136/jisakos-2020-000503)
  • [L3] [27] (10.1177/0363546514529643)
  • [L2] If removal on demand of the syndesmotic screw is non-inferior to routine removal in terms of functional outcome, this will offer a strong argument to adopt this as standard practice of care, meaning patients will not have to undergo a secondary procedure, leading to less complications and subsequent lower costs. [28] (10.1186/s12891-018-1946-5)
  • [L4] [29] (10.1016/j.asmr.2025.101227)
  • [L4] Good results are achieved by anatomic reconstruction of the anterior syndesmosis, and all patients in this study would undergo the surgery again if necessary. [30] (10.1186/1471-2474-12-212)
  • [L5] Accurate reduction and stable fixation of the syndesmosis are critical to maximize patient outcomes, as malreduction is a significant predictor of poor functional results. [32] (10.5435/jaaos-d-14-00233)
  • [L4] Flexible fixation was the preferred device choice for syndesmotic injury repair, and most respondents did not alter rehabilitation protocols based on injury severity, though considerable variability existed in return to activity times. [33] (10.1016/j.jisako.2021.10.005)
  • [L3] Suture-button treatment for acute isolated ankle syndesmotic injuries leads to favorable clinical and radiological outcomes with maintained ankle stability. [34] (10.1186/s12891-024-07849-5)
  • [L4] Chronic syndesmotic instability and chronic medial ankle instability are significantly associated with unsatisfactory outcomes in patients with chronic ankle instability. [35] (10.1016/j.arthro.2015.02.021)
  • [L3] The embrace technique yielded equivalent outcomes compared with suture button fixation for managing syndesmotic injuries. [36] (10.1186/s13018-025-06620-3)
  • [L5] Injury propagation was not identical in all ankles that sustained a syndesmotic injury, but a characteristic sequence initiated with injuries to the medial ligaments, particularly the superficial deltoid, followed by the propagation of injuries to either the syndesmotic or lateral ligaments, and finally to the interosseous membrane or the fibula. [38] (10.1177/2325967118781333)
  • [L4] Isolated anterior syndesmosis diastasis without fracture is a rare entity that can be easily missed in routine X-rays, where computed tomography is useful for diagnosis in cases of clinical suspicion. [40] (10.1007/s00402-007-0296-9)
  • [L1] Orthopaedic surgeons should consider using WBCT syndesmotic area measurements as an isolated, accurate, practical, and reliable marker of syndesmotic instability. [42] (10.1097/corr.0000000000002223)
  • [L5] [45] (10.5435/jaaos-d-19-00358)
  • [L2] Traditional radiographic measurements should not be relied on solely for determining if the syndesmosis is intact and the ankle mortise is stable. [47] (10.1097/01.blo.0000161090.86162.19)
  • [L4] Despite rigid fixation of the posterior malleolus, syndesmotic instability was more prevalent than expected, though the short-term complication rate was low. [48] (10.1016/j.injury.2019.10.007)
  • [L3] However, further prospective studies are required to determine the efficacy of this method in reducing the syndesmosis over other methods that exists. [49] (10.1097/corr.0000000000001348)
  • [L3] After surgical stabilization of an unstable syndesmotic injury, full weight bearing did not lead to syndesmotic diastasis in the early post-operative period. [50] (10.1016/j.injury.2019.02.014)
  • [L1] [52] (10.2106/jbjs.16.01382)
  • [L3] Furthermore, this method has a similar operative time to fluoroscopy and eliminates radiation exposure, supporting its feasibility as an efficient and safe alternative for syndesmotic screw removal. [53] (10.1186/s12891-026-09569-4)
  • [L4] The anatomical approach, which directly fixes broken fragments and repairs torn ligaments, is effective in reducing the rate of syndesmosis malreduction, increasing biomechanical strength, and avoiding the need for trans-syndesmotic fixation and its secondary removal. [55] (10.1302/2058-5241.3.170017)
  • [L5] The distal tibiofibular dislocation injury of the ankle with an intact fibula may present with subtle clinical features. [69] (10.1016/s0020-1383(01)00193-0)
  • [L2] Pre-operative 3.0-T MRI demonstrated excellent accuracy in the diagnosis of syndesmotic ligament tears and allowed for the visualization of relevant individual syndesmosis structures. [75] (10.1007/s00167-014-3399-1)
  • [L2] Most studies found distinct characteristics of the incisura fibularis morphology associated with ligamentous ankle lesions, potentially due to lower osseous resistance against tibiofibular displacement. [77] (10.1016/j.jisako.2024.100361)
  • [L5] In a biostatic model, one-sixth of the static load of the leg was carried by the fibula, a force generated by the fibula's articulation with the talus and possibly the inferior tibiofibular ligaments. [78] (10.2106/jbjs.25.00088)
  • [L4] Bolt fixation efficiently stabilises the syndesmosis during healing and provides reliable syndesmotic reduction. [79] (10.1016/j.injury.2009.02.013)
  • [L4] Arthroscopy-assisted treatment of latent syndesmotic instability is an effective method, showing statistically significant improvement in AOFAS scores for pain and function at final follow-up. [82] (10.1016/j.arthro.2008.02.013)
  • [L5] Stability of the loaded ankle is primarily due to the deltoid ligament, which exerts a restraining influence on external rotation of the talus. [93] (10.2106/00004623-199607000-00006)
  • [L4] [95] (10.1302/2058-5241.6.210017)
  • [L5] Although it reflects a normal anatomical finding, it could lead to anterolateral impingement in cases with coexistent ankle instability. [100] (10.1177/0095399703258697)
  • [L5] The choice of screw fixation as a treatment for ankle syndesmosis disruption should be carefully evaluated. [107] (10.1007/s00402-006-0131-8)
  • [L4] Long-term functional outcomes at a mean of twenty-one years after pronation-external rotation ankle fractures treated with one or two syndesmotic screws were good to excellent in the great majority of patients despite substantial radiographic evidence of osteoarthritis in one-half of the patients. [111] (10.2106/jbjs.l.00426)
  • [L4] At mid-term follow-up, the operative group appeared to report higher levels of ankle-related function, however these differences were not statistically significant. [113] (10.1177/2325967126s00317)
  • [L3] CT was superior to simple radiography in predicting syndesmotic injury at the preoperative period in SER-type III and IV. [114] (10.1016/j.injury.2019.05.020)
  • [L4] Weight-bearing radiographs provide a more functionally accurate assessment of syndesmotic integrity than non-weight-bearing imaging and should be incorporated into routine diagnostic protocols, especially for active individuals and those with higher BMI. [115] (10.1186/s13018-025-05886-x)
  • [L5] Most isolated trans-syndesmotic fibular fractures are stable and can be treated non-operatively, while posterior malleolus fractures should be considered for surgical fixation to restore stability. [117] (10.1302/2058-5241.3.170057)
  • [L3] This study provides the first insights based on 3D measurements to support the potential relevance of applying external rotation during WBCT imaging to enhance diagnostic accuracy of subtle syndesmotic instability. [119] (10.1007/s00167-023-07536-3)
  • [L3] Syndesmotic joint volume measurements seem to be best suited to diagnose syndesmotic instability among patients with Weber B ankle fractures, compared with other two-dimensional and three-dimensional WBCT measurements. [122] (10.5435/jaaos-d-21-00566)
  • [L4] [124] (10.1097/01.blo.0000052935.71325.30)
  • [L4] The oblique axial magnetic resonance imaging scan revealed that the prevalence of transverse ligament and posterior inferior tibiofibular ligament injuries in syndesmosis-injured ankles were 76.5 and 41.2%, respectively. [125] (10.1186/s12891-022-05220-0)
  • [L3] Three-dimensional imaging may improve tibiofibular malreduction visualization in bimalleolar/trimalleolar/dislocated type Weber B fractures and in isolated type Weber C fractures with syndesmotic transfixation. [126] (10.1016/j.injury.2018.04.027)
  • [L3] The clinical diagnosis of Salter-Harris I fracture of the distal fibula was incorrect in 100% of cases; instead, MRI identified ligamentous sprains and/or bony contusions in almost 90% of patients. [127] (10.1016/j.injury.2010.04.015)
  • [L4] The Chertsey test proved to be an easy and reliable adjunct to ankle fixation surgery, clearly demonstrating syndesmosis injury and confirming accurate fibular reduction without the need for further radiological investigation or surgical intervention. [129] (10.1016/j.injury.2016.03.005)
  • [L2] The anterior tibio fibular distance widened after one year of syndesmotic screw removal. [132] (10.1016/j.injury.2016.07.031)

See Also

References

[1] Ankle Syndesmotic Injury. Journal of the American Academy of Orthopaedic Surgeons. 2007. DOI: 10.5435/00124635-200706000-00002

[2] The fate of the syndesmosis in type C ankle fractures: a cadaveric study. Injury. 1997. DOI: 10.1016/s0020-1383(97)00010-7

[3] Acute and Chronic Injuries to the Syndesmosis. Clinics in Sports Medicine. 2015. DOI: 10.1016/j.csm.2015.06.009

[4] Acute, isolated and unstable syndesmotic injuries are frequently associated with intra‐articular pathologies. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-06141-y

[5] Delayed stabilisation of dynamically unstable syndesmotic injuries results in worse functional outcomes. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-05962-1

[6] Technical aspects of the syndesmotic screw and their effect on functional outcome following acute distal tibiofibular syndesmosis injury. Injury. 2014. DOI: 10.1016/j.injury.2013.09.035

[7] Better outcome for suture button compared with single syndesmotic screw for syndesmosis injury: five-year results of a randomized controlled trial. The Bone & Joint Journal. 2020. DOI: 10.1302/0301-620x.102b2.bjj-2019-0692.r2

[8] A systematic review of studies on the diagnostics and classification system used in surgically treated, acute, isolated, unstable syndesmotic injury: a plea for uniform definition of syndesmotic injuries. EFORT Open Reviews. 2024. DOI: 10.1530/eor-23-0097

[9] Management of syndesmotic injuries of the ankle. EFORT Open Reviews. 2017. DOI: 10.1302/2058-5241.2.160084

[10] Arthroscopic Reconstruction of the Posteroinferior Tibiofibular Ligament: An Operative Technique. Arthroscopy Techniques. 2025. DOI: 10.1016/j.eats.2024.103418

[11] Paper #44: Treatment of Chronic Syndesmotic Injury: A Systematic Review and Meta‐Analysis. Arthroscopy. 2013. DOI: 10.1016/j.arthro.2013.07.048

[12] Factors associated with adverse events after distal tibiofibular syndesmosis fixation. Injury. 2020. DOI: 10.1016/j.injury.2019.12.011

[13] Treatment of chronic syndesmotic injury: a systematic review and meta‐analysis. Knee Surgery, Sports Traumatology, Arthroscopy. 2013. DOI: 10.1007/s00167-013-2515-y

[14] Syndesmotic screw fixation in Weber C ankle injuries–should the screw be removed before weight bearing?. Injury. 2006. DOI: 10.1016/j.injury.2006.02.003

[15] Can Weightbearing Cone-beam CT Reliably Differentiate Between Stable and Unstable Syndesmotic Ankle Injuries? A Systematic Review and Meta-analysis. Clinical Orthopaedics & Related Research. 2022. DOI: 10.1097/corr.0000000000002171

[16] MRI for high ankle sprains with an unstable syndesmosis: posterior malleolus bone oedema is common and time to scan matters. Knee Surgery, Sports Traumatology, Arthroscopy. 2019. DOI: 10.1007/s00167-019-05581-5

[17] Cadaveric Diagnostic Study of Subtle Syndesmotic Instability Using a 3-Dimensional Weight-Bearing CT Distance Mapping Algorithm. Journal of Bone and Joint Surgery. 2024. DOI: 10.2106/jbjs.24.00199

[18] Injuries to the Distal Lower Extremity Syndesmosis. Journal of the American Academy of Orthopaedic Surgeons. 1997. DOI: 10.5435/00124635-199705000-00006

[20] High Ankle Sprains and Syndesmotic Injuries in Athletes. Journal of the American Academy of Orthopaedic Surgeons. 2015. DOI: 10.5435/jaaos-d-13-00135

[21] Syndesmosis Instability. Orthopaedic Journal of Sports Medicine. 2023. DOI: 10.1177/2325967121s00851

[22] Nonoperative Management of High Ankle Sprains: A Case Series With ≥18-Year Follow-up. The American Journal of Sports Medicine. 2024. DOI: 10.1177/03635465241271593

[24] Diagnosis and Treatment of Syndesmotic Unstable Injuries: Where We Are Now and Where We Are Headed. Journal of the American Academy of Orthopaedic Surgeons. 2021. DOI: 10.5435/jaaos-d-20-01350

[25] High Ankle Sprains in Professional Ice Hockey Players: Prognosis and Correlation Between Magnetic Resonance Imaging Patterns of Injury and Return to Play. Orthopaedic Journal of Sports Medicine. 2019. DOI: 10.1177/2325967119871578

[26] Limited intrarater and interrater reliability of acute ligamentous ankle injuries on 3 T MRI. Journal of ISAKOS. 2021. DOI: 10.1136/jisakos-2020-000503

[27] Ligamentous Injuries and the Risk of Associated Tissue Damage in Acute Ankle Sprains in Athletes. The American Journal of Sports Medicine. 2014. DOI: 10.1177/0363546514529643

[28] Routine versus on demand removal of the syndesmotic screw; a protocol for an international randomised controlled trial (RODEO-trial). BMC Musculoskeletal Disorders. 2018. DOI: 10.1186/s12891-018-1946-5

[29] Suture‐Button Repair Improves Outcomes in Arthroscopically Diagnosed Chronic Syndesmotic Injury Despite Low Imaging Sensitivity. Arthroscopy, Sports Medicine, and Rehabilitation. 2025. DOI: 10.1016/j.asmr.2025.101227

[30] Chronic instability of the anterior tibiofibular syndesmosis of the ankle. Arthroscopic findings and results of anatomical reconstruction. BMC Musculoskeletal Disorders. 2011. DOI: 10.1186/1471-2474-12-212

[32] Technical Considerations in the Treatment of Syndesmotic Injuries Associated With Ankle Fractures. Journal of the American Academy of Orthopaedic Surgeons. 2015. DOI: 10.5435/jaaos-d-14-00233

[33] Significant variations in surgical construct and return to sport protocols with syndesmotic injuries: an ISAKOS global perspective. Journal of ISAKOS. 2022. DOI: 10.1016/j.jisako.2021.10.005

[34] Outcome of flexible fixation for acute isolated syndesmotic injuries. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-07849-5

[35] Concomitant Syndesmotic Instability and Medial Ankle Instability Are Risk Factors for Unsatisfactory Outcomes in Patients With Chronic Ankle Instability. Arthroscopy. 2015. DOI: 10.1016/j.arthro.2015.02.021

[36] Outcomes of suture button fixation versus embrace fixation for syndesmotic injury. Journal of Orthopaedic Surgery and Research. 2026. DOI: 10.1186/s13018-025-06620-3

[37] Aaos Comprehensive Orthopaedic Review 3. Acute and Chronic Injuries of the Ankle > IV. Syndesmotic Instability.

[38] Propagation of Syndesmotic Injuries During Forced External Rotation in Flexed Cadaveric Ankles. Orthopaedic Journal of Sports Medicine. 2018. DOI: 10.1177/2325967118781333

[40] Isolated anterior syndesmosis diastasis without fracture. Archives of Orthopaedic and Trauma Surgery. 2007. DOI: 10.1007/s00402-007-0296-9

[42] CORR Insights®: Can Weightbearing Cone-beam CT Reliably Differentiate Between Stable and Unstable Syndesmotic Ankle Injuries? A Systematic Review and Meta-Analysis. Clinical Orthopaedics & Related Research. 2022. DOI: 10.1097/corr.0000000000002223

[43] Aaos Comprehensive Orthopaedic Review 3. Arthroscopy of the Ankle > IV. Syndesmotic Impingement.

[45] Syndesmosis Injury From Diagnosis to Repair: Physical Examination, Diagnosis, and Arthroscopic-assisted Reduction. Journal of the American Academy of Orthopaedic Surgeons. 2020. DOI: 10.5435/jaaos-d-19-00358

[47] Radiographic Measurements Do Not Predict Syndesmotic Injury in Ankle Fractures. Clinical Orthopaedics and Related Research. 2005. DOI: 10.1097/01.blo.0000161090.86162.19

[48] Posterior pilon fracture: Epidemiology and surgical technique. Injury. 2019. DOI: 10.1016/j.injury.2019.10.007

[49] Is the Fibular Station on Lateral Ankle Radiographs Symmetric? A Retrospective Observational Radiographic Study. Clinical Orthopaedics & Related Research. 2020. DOI: 10.1097/corr.0000000000001348

[50] Syndesmotic fixation in unstable ankle fractures: Does early post-operative weight bearing affect radiographic outcomes?. Injury. 2019. DOI: 10.1016/j.injury.2019.02.014

[52] Early, Rather than Late, Weight-Bearing and Range-of-Motion Exercise Improved Early Function But Not Time to Return to Work After Surgical Fixation of Unstable Ankle Fractures. Journal of Bone and Joint Surgery. 2017. DOI: 10.2106/jbjs.16.01382

[53] Removal of syndesmotic screws – is sonography a precise and efficient method of guidance?. BMC Musculoskeletal Disorders. 2026. DOI: 10.1186/s12891-026-09569-4

[55] Repair of syndesmosis injury in ankle fractures. EFORT Open Reviews. 2018. DOI: 10.1302/2058-5241.3.170017

[56] Rockwood And Green S Fractures In Adults. 59: Patellar Fractures and Dislocations and Extensor Mechanism Injuries > Syndesmotic Injuries.

[69] Distal tibiofibular joint dislocation with an intact fibula: a classification system. Injury. 2003. DOI: 10.1016/s0020-1383(01)00193-0

[75] Magnetic resonance imaging characterization of individual ankle syndesmosis structures in asymptomatic and surgically treated cohorts. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3399-1

[77] Ligamentous ankle injuries in relation to the morphology of the incisura fibularis: A systematic review. Journal of ISAKOS. 2025. DOI: 10.1016/j.jisako.2024.100361

[78] High-Quality Evidence That a Postoperative Protocol of Immediate Weight-Bearing Is Superior to Non-Weight-Bearing and Cast Use After Operatively Treated Malleolar Ankle Fractures. Journal of Bone and Joint Surgery. 2025. DOI: 10.2106/jbjs.25.00088

[79] Bolt fixation for syndesmotic injuries. Injury. 2009. DOI: 10.1016/j.injury.2009.02.013

[82] Arthroscopy‐Assisted Repair of Latent Syndesmotic Instability of the Ankle. Arthroscopy. 2008. DOI: 10.1016/j.arthro.2008.02.013

[93] Motion of the Ankle in a Simulated Supination-External Rotation Fracture Model. The Journal of Bone & Joint Surgery*. 1996. DOI: 10.2106/00004623-199607000-00006

[95] Ankle and syndesmosis instability: consensus and controversies. EFORT Open Reviews. 2021. DOI: 10.1302/2058-5241.6.210017

[100] The Accessory Anteroinferior Tibiofibular Ligament as a Cause of Talar Impingement. The American Journal of Sports Medicine. 2004. DOI: 10.1177/0095399703258697

[107] The distal tibiofibular syndesmosis during passive foot flexion. RSA-based study on intact, ligament injured and screw fixed cadaver specimens. Archives of Orthopaedic and Trauma Surgery. 2006. DOI: 10.1007/s00402-006-0131-8

[111] Long-Term Outcome of Pronation-External Rotation Ankle Fractures Treated with Syndesmotic Screws Only. Journal of Bone and Joint Surgery. 2013. DOI: 10.2106/jbjs.l.00426

[113] Paper 60. Preliminary Outcomes and GPS Device-Measured Load and Performance Following High Ankle Sprains and Return-to-Sport in Division 1 Football Players: Comparing Semirigid Fixation and Non-Surgical Management. Orthopaedic Journal of Sports Medicine. 2026. DOI: 10.1177/2325967126s00317

[114] Relationship between fracture morphology of lateral malleolus and syndesmotic stability after supination-external rotation type ankle fractures. Injury. 2019. DOI: 10.1016/j.injury.2019.05.020

[115] Radiographic comparison of weight-bearing and non-weight-bearing positions in evaluating the distal tibiofibular syndesmosis: a single-center study of 72 ankles. Journal of Orthopaedic Surgery and Research. 2025. DOI: 10.1186/s13018-025-05886-x

[117] Stability in ankle fractures. EFORT Open Reviews. 2018. DOI: 10.1302/2058-5241.3.170057

[119] Application of external torque enhances the detection of subtle syndesmotic ankle instability in a weight‐bearing CT. Knee Surgery, Sports Traumatology, Arthroscopy. 2023. DOI: 10.1007/s00167-023-07536-3

[122] Utility of WBCT to Diagnose Syndesmotic Instability in Patients With Weber B Lateral Malleolar Fractures. Journal of the American Academy of Orthopaedic Surgeons. 2021. DOI: 10.5435/jaaos-d-21-00566

[124] Syndesmotic Disruption in Low Fibular Fractures Associated With Deltoid Ligament Injury. Clinical Orthopaedics and Related Research. 2003. DOI: 10.1097/01.blo.0000052935.71325.30

[125] The prevalence of posterior inferior tibiofibular ligament and inferior tibiofibular transverse ligament injuries in syndesmosis-injured ankles evaluated by oblique axial magnetic resonance imaging: a retrospective study. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-022-05220-0

[126] Incidence and severity of malreduction of the tibiofibular syndesmosis following surgical treatement of displaced ankle fractures and impact on the function –Clinical study and MRI evaluation. Injury. 2018. DOI: 10.1016/j.injury.2018.04.027

[127] Magnetic resonance imaging of clinically suspected Salter–Harris I fracture of the distal fibula. Injury. 2010. DOI: 10.1016/j.injury.2010.04.015

[129] A new assessment for syndesmosis injury – The ‘Chertsey test’. Injury. 2016. DOI: 10.1016/j.injury.2016.03.005

[132] Changes in the syndesmotic reduction after syndesmotic screw fixation for ankle malleolar fractures: One-year longitudinal evaluations using computer tomography. Injury. 2016. DOI: 10.1016/j.injury.2016.07.031

[133] WITH SPECIAL REFERENCE TO PERONEAL-NERVE BLOCK AS A DIAGNOSTIC ALD*. 1951.

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